# Battery Strings, Banks, Terminals, Cables.



## JeepHammer (May 12, 2015)

Using batteries for back up power, or power storage, like singing,
Everyone can do it, but only a few will do it well outside the shower!

People that are familiar with Alternating Current (AC) get completely stumped and make a ton of mistakes when it comes to Direct Current (DC).

AC & DC have completely different rules for efficient & effective useage!

AC seeks an 'Earth Ground', a conductive metal rod driven into the actual ground under your feet,

While DC seeks to complete a circuit back to the opposite terminal from its original source.

A DC source, such as a battery or a solar panel, will have a Positive & Negative,
Current THEROY is the Positive will seek its polar opposite, which is Negative.
At no time will DC seek an earth 'Ground'.

When you work with DC, the most common useage is automotive.
If you hook up a light or what ever,
You give that DC load a good Positive, but its usually a mistake to hook the load Negative to sheet metal and call it a 'Ground'.

Your load/appliance will work MUCH better if you give it a solid Negative path back to the battery,
Mostly since steel and cast iron are HORRIBLE conductors of DC current.
Steel is high resistance, cast iron is very high resistance and cripples the full connection of the DC circuit.

Again, when you are working with DC, forget about 'Grounds',
You don't have a metal rod driven to 'Earth Ground' with a long wire/cable to keep you 'Grounded',
When working with DC, think 'Negative Path' back to the battery or other power source.
If you take as much care with the Negative as you do with the Positive,
Your system will show you MUCH more efficiency and a lot less problems.


----------



## JeepHammer (May 12, 2015)

When you select terminals, especially that will connect to batteries or be in close proximity to batteries, take care what you choose!

Bare copper is attacked and destroyed very quickly by battery acid and gasses,
So using bare copper anywhere around a battery is a failure in the making...
Most of us have better things to do with our time than continuously tracking down failed or failing connections and replacing terminal ends.

Choosing a terminal end that won't fail in short order isn't as simple as it seems...

LINK: http://www.civilianjeep.info/Wiring/Winch/WinchInstall25.gif

This image shows Flattened Barr Copper Tubing Terminals,
Right next to solid copper, Blind Cable Socket, lead/silver cadmium plated terminals.

First off is contact patch, notice the narrow area between the hole for a bolt and the edge of the flattened tubing?
This is a higher quality piece, some are MUCH thinner.
This narrow strip that will be compressed by a bolt or nut simply isn't big enough to properly conduct high amperage efficiently.

Notice the very large contact face on the heavy plated terminals?
Good, solid, high amperage connection with this amount of contact patch.


----------



## JeepHammer (May 12, 2015)

OK, lets see if I can get image links to post...
Since Its my understanding this forum lays a copyright on any image you post,
And since I do technical writing and use my images, already copyrighted by me,
I will have to post links to the images instead of post them directly.

Sorry for the extra steps...

------------

You can have a HUGE solar electric panel field,
You can have a truck load of the most powerful batteries,
You can have the most powerful generator,
BUT,
Its all for very little unless you pay attention to the Cables & Wires (Conductors),
And the Terminal Ends on those Wires/Cables!

This is a link to some Terminals & Cables,
LINK: http://www.civilianjeep.info/Wiring/Winch/WinchInstall01.gif

Don't be fooled by the automotive link, this is still the same way you should make any High Amperage DC cables...

Top Left, Anderson Connector Cover, rubber cover used to protect the open end of the Anderson connector when its not in use.

Top, Second Left, High Amperage Anderson Connector.

Top, Third Left, this is a flattened tubing connector,
This one is fairly heavy copper, Nickel plated against corrosion,
This is MINIMUM terminal end I would ever use...

Top, Middle.
This is a heavy duty 'Splice' connector, also used for stud terminals.
This particular terminal is lead/silver cadmium plated against corrosion,
It also has 'Blind' sockets for the cables,
I'll explain that in depth further on.

Top, Third Right,
A POSITIVE battery terminal clamp,
Not one of those cheap lead 'Universal' clamps that don't fit either terminal correctly.

Top, Two Right,
These are Splice & Stud/Bolt terminals,
Again, solid Copper, Blind Socket, Lead/Silver Cadmium plated to resist corrosion.

MIDDLE,
Left, Vinyl insulated 'Battery' cable, thicker strands,
And keep in mind Vinyl burns furiously.

Middle Right, High Amperage rubberized insulation welding cable.

BOTTOM, Heavy Crimpers for Heavy Duty Terminal Ends,
And a set of cable cutters.

----- 

If you have a good look at the picture, you will see a few things that most Solar Installers don't know exist...
Solar installers are fond of 'Quick' instead of built to last...

This is something you should take the time to do for your system since you normally only do it ONCE, and the efficiency usually is 10% or more increase,
And your system doesn't decline as time goes by.

As I go through these terminals/cables & explanations, you will see why these do so much better and last so much longer!


----------



## JeepHammer (May 12, 2015)

Now, This Is What Happens When You Don't Pay Attention To Details...

This particular cable wasn't in service a year when it developed a serious issue.
This was a mystery since the issue wasn't visable,
When large loads were demanded, the cable couldn't supply the amperage needed and the Circuit Breakers kicked the circuit out before the cable overheated to the point of total failure...

Since it was an intermittent problem, and the cable didnt get hot enough from corrosion resistance to locate the issue, it was VERY hard to find!

LINK: http://www.civilianjeep.info/Wiring/Winch/WinchInstall12.gif

This particular failure was a crimped terminal end, no solder, connected to a battery bank.
The acid creeped into the flattened tubing terminal,
Capillary movement of liquid moved the acid right into the cable strands,
No external signs of corrosion to speak of...

This is an image of why you check the pre-made, off the shelf cables,
Flattened tubing terminals crimped on, no solder, and the heat shrink is cheap, no glue to seal up the connections,

LINK: http://www.civilianjeep.info/Wiring/Winch/BadTerminals03.gif

Notice the Heat Shrink that is for decoration,
The crimping die tore a hole in the terminal sockets!
Direct access hole for any contamination!

Pre-Made cables are usually made with as cheap of components,
And put together as cheaply as possible,
I've got to the point I won't use them at all...


----------



## Darren (May 10, 2002)

Who sells the crimp on terminals? I've been looking for those to relocate a tractor battery. Have you used one of the hydraulic crimpers? Do you use dielectric grease? Do You solder the connections after crimping?


----------



## JeepHammer (May 12, 2015)

For small systems,
Find a battery supply shop that sells the good terminals, cables, heat shrink,
And most times you won't have to buy the heavy duty crimping tool,
If you buy from them, normally the will cut the cable, set the heat shrink on the cable, and crimp on the ends they sold you for free.

Take those cables home, solder on the ends, and shrink the tubing in place.

If you have a larger system, it pays to buy the cable, terminals & heat shrink in bulk,
Pay the $300 for a good crimper tool,
And make your own to exactly & specifically fit your application.

For larger cables,

Silver Bearing Electrical Solder, Rosin Core.
(Acid Core Plumbing solder will corrode your work as quickly as battery contact will! NO ACID CORE SOLDER EVER!)

Silver Bearing Solder will have a 2% to 4% silver content normally.
True Silver Solder & Silver Bearing ELECTRICAL Solder are NOT the same thing,
Actual Silver Solder is very expensive and takes more heat to melt than Electrical Solder does.

Heat Shrink Tubing,
The 'Dull' rubberized kind, NOT the shiny 'Vinyl' kind,
And make sure it has glue inside!
That glue makes all the difference when you cables are exposed to moisture or batteries!

Solid Terminals with 'Blind' cable/wire sockets.
If you are forced to use flattened tubing terminal ends,
Make sure you solder the socket shut BEFORE you install the cable so acid/moisture can't creep up the seperation line where the tubing was flattened.

For high amperage DC, stick to Welding Cable,
Its usually virgin (pure) copper, no alloys,
And its finer strands, which means its easier to bend/work with mechanically,
Finer strands also means it packs tighter, more copper to carry load in the same size cable.
Insulation on welding cable is also better suited to this particular application.

A Propane or MAPP gas torch,
This is the ONLY way to get the terminal hot enough for solder to flow.
Copper moves heat VERY quickly, soldering irons & pen size torches simply won't do the job.

Cable cutters that will CLEANLY cut through large gauge cable.

Heavy Duty Crimping Tool.
You must get enough leverage to crimp a heavy duty terminal end onto the cable,
And this is NOT a flimsy flattened tubing terminal,
A good sold copper terminal is going to take several hundred pounds per square inch of pressure, you simply can't produce that with a set of flimsy 'Pliers'.

A SOLID MECHANICAL CRIMP,
This is required!
*IF* something goes wrong in your system,
A solder only connection CAN DE-SOLDER itself!
Without a sold mechanical crimp, the cable can and will pull out of the terminal when de-soldering takes place...

CRIMP: http://www.civilianjeep.info/Wiring/Winch/WinchInstall08.gif

Something as simple as a loose bolt or nut can create enough resistance to cause a de-solder situation.

Crimp is a mechanical connection,
To make an ELECTRICAL connection, you have to solder.
Heat the TERMINAL, not the cable or socket!

A simple way to know EXACTLY when you have enough heat is to cut a small piece of solder,
Wrap it around the cable next to the terminal socket,
When the solder melts STOP THE HEAT,
Feed solder into the socket.

Take Note: Silver Bearing ELECTRICAL Solder...

SOLDER: http://www.civilianjeep.info/Wiring/Winch/WinchInstall09.gif

There will be plenty of heat left to melt as much solder as you need.

Heat Shrink,
DO NOT apply the heat shrink directly to the connection!
There will be TOO MUCH HEAT and you will damage the heat shrink!

Wait until the connection cools down quite a bit,
Then slide heat shrink into place,
USE A HEAT GUN to shrink the tubing,
Starting at the terminal and moving your way back to the cable,
Keep moving the heat gun to get a uniform shrink all the way around the terminal/cable.

DO NOT USE A TORCH TO SHRINK THE TUBING!
You WILL damage the tubing causing it to fail prematurely.

HEAT SHRINK: http://www.civilianjeep.info/Wiring/Winch/WinchInstall10.gif

You will screw one, or all of these steps once or twice before you get the hang of making your own cables,
But when you acquire this skill, you will make BULLET PROOF CABLES on demand, 
And your cables will far outlive anything currently on the market I've seen...

You won't save any money, but your cables will have roughly TWICE the capacity of the pre-mades, and the service life will be several times longer than the pre-mades.

FINISHED TERMINATION OF CABLES,
Notice the glue beading up at the ends of the heat shrink letting you know you have an Enviornmental Seal against the enemies of your expensive copper!

http://www.civilianjeep.info/Wiring/Winch/WinchInstall11.gif

--------------

SOURCES:
I'm not going to list particular part numbers from warehouses/dealers,
Those change all the time.

Start with welding cable, good high amperage terminals, heat shrink, ect,
Obviously, it makes sense to start at a welding supply shop!

The biggest verity of VERY high amperage terminals,
Heavy Equipment supply & parts stores.
Heavy Truck Supply houses.

Heavy equipment will draw way more amperage than about any solar system,
Some heavy equipment will draw 4,000 Amps to get it started!

The largest single inverter for solar I've seen up close was 7,500 Watts output.
7,500 Watts Devided by 24 Volts = 312 Amps from a SINGLE battery string!
Cables/Terminals that are capable of 4,000 Amps will deliver 312 Amps continously with no issues!
(Try that with pre-made cables and you will have a fire!)

That same 7,500 Watt Inverter at 48 Volts,
7,500 Watts Devided by 48 Volts = 156 Amps,
Now you are talking smaller cables to do the same job.

More on cable sizing in another post when I get time...

If the terminals, correctly positioned on heavy equipment,
Under the worst possible contamination/corrosion conditions,
The worst possible vibration/mechanical conditions will still get that heavy equipment running,
Think how long it will last in you fairly small solar system!

Catalog sources for terminals include, but not limited to,
EBay, McMaster-Carr, Granger, NAPA, ACE Battery, and a host of other retailers.


----------



## JeepHammer (May 12, 2015)

SIZING YOUR CABLES FOR YOUR APPLICATION.

Maybe one person will have followed along to this point,
This is where I loose even them...

In a recent thread, a guy was considering a 4,500 Watt Output Inverter that would surge momentarily to 7,000 Watts.

For a continous 4,500 Watt output,
And to be safe, you ALWAYS size your cables to the Maximum 'Normal' current draw, plus 25%.
The added 25% is safety margin, surge, potential corrosion resistance, ect.

Math is ALWAYS where you loose people, but here we go anyway...

4,500 Watts Nominal + 25% = 5,625 Watts draw potential from the batteries.
24 Volt Battery strings devided into 5,625 Watts = 234 Amps.

48 Volt Battery strings devided into 5,625 Watts = 117 Amps.

Now, to find the MINIMUM cable gauge size, you consult the Brown & Sharp Scale,
Look in the 'Amps' column for your target Amperage,

LINK: http://www.civilianjeep.info/Wiring/B&Sscale01.gif










For 24 Volts, you are looking at a REALLY large 000 Ga. (Also expressed as 3/0 Ga.) to carry that 234 Amps safely without heating up.

For 48 Volts, you are looking at a much more common 2 Ga. Cable to carry 117 Amps safely without heating up.

Now remember, you are going to see wire gauge/amperage scales all over the Internet.
The Brown & Sharp Scale is the DIRECT CURRENT STANDARD.
The Internet amperage/wire gauge sizing charts you find are for AC, NOT DC!
You can cause yourself real problems by using an AC scale for DC,
Just like AC works okay with aluminum or alloy wire,
But aluminum or alloy wire is a disaster with DC!

SO!
With this particular Inverter, your MAIN lines to your battery strings are pretty well laid out.

We'll go through it again with a 2,500 Watt Output Inverter.

2,500 Watts + 25% safety margin = 3,125 Watt Capicity.
3,125 Watts Devided by 24 Volts = 130 Amps.
3,125 Watts Devided by 48 Volts = 65 Amps.

Again, reference the 'Amps' column,
24 Volt String, 130 Amps, 2 Ga. Cable.
48 Volt String, 65 Amps, 6 Ga. Cable.
These are MINIMUM safe gauges.


----------



## JeepHammer (May 12, 2015)

Darren said:


> Who sells the crimp on terminals? I've been looking for those to relocate a tractor battery. Have you used one of the hydraulic crimpers? Do you use dielectric grease? Do You solder the connections after crimping?


NAPA has heavy terminals in smaller gauges,
You will have to find a NAPA that carries truck supplies to get larger gauges on the shelf or order them.

Granger Supply catalog has a mind boggling array of LUGS (ring & eyes),
And heavy battery post terminals.

This is a link to a site that has a front page that will educate,
LINK: http://crimpsupply.com/battery-terminals-copper-lugs

I do use dielectric grease, Especally in small gauge wire connectors to add moisture protection.

I use a 'Red' spray on battery terminal protector on battery connections.

I have a hydraulic crimper, its dies often don't fit the heavy duty thick walled terminals needed to conduct full current from batteries to inverter.

I solder every connection,
ELECTRICAL, Rosin Core, Silver Content Bearing Solder.

No matter how hard you crimp the terminal on the cable,
There are still pathways for Oxygen, Moisture, Acid to get into the terminal & cable copper.
The solder seals up the terminal, 'Tins' the exposed copper of the cable,
Silver 'Floats' on the outside skin of the solder, and provides an extra layer of protection.
Silver also sticks to the copper itself, providing a superior electrical connection between cable & terminal.

When you look at terminals, think CONTACT PATCH.
The surface area that contacts the battery terminal surface area.
You can NOT increase the contact surface area of the battery,
You CAN get terminals that contact 100% of the battery.

When you look at round terminal clamps,
Look at how high the sides of that terminal are.
The taller the sides, the more battery post you will contact with.

When you are looking at Lugs, you want the lug to be at least as wide as the flat surface contact area on the battery.
Hanging over a little doesn't hurt anything...
And you know you have 100% of the availabe contact surface area covered.

--------

Soldering Tips,

DO NOT EVER use Acid Core or 'Plumbing' solder on an ELECTRICAL connection!
Do NOT use liquid cleaners (Acid!) to clean copper in an electrical connection.

If you need to clean the terminals, you are better off with emery cloth, sand paper or a CLEAN wire brush.

One tip to know when you have reached sufficient heat to make solder flow into the cable/terminal connection is to stick a short piece of solder in the cable strands between insulation and terminal,
Or to wrap a short piece of solder around the cable between insulation & terminal,
When the terminal/cable hit the correct temp, the solder will dissapear into the cable/terminal.
This is when you start feeding solder into the connection and remove heat.

This approach keeps you from seriously overheating the terminal or cable/insulation.

Never try to melt solder directly, always allow the terminal to heat the cable allowing solder to melt freely, flow freely.
If you try to melt the solder with direct heat, the solder is going to run off instead of flow into your connection.

Angle your cable, terminal down 15 or 20 degrees,
Heat the terminal!
Not the socket or cable, let the heat creep into the connection at its own pace.

You want the heat to 'Crawl' up the terminal/cable insuring the entire connection is at a proper temp to get solder flowing into the joint.

What NOT to do!
Don't stand the terminal 'Up' 90 Degrees,
The solder will have a tendancy to run down the cable and make it stiff as a board!
It also damages the insulation.

Do NOT stand the terminal Down 90 Degrees,
Heat rises, and will damage the insulation, Especally if you are using a torch!

Under Heated Solder looks 'Clumpy' and doesn't flow into the connection leaving room for corrosives to enter,

Over Heated Solder turns 'Dull' colored, doesn't shine,
Over cooked solder won't hold onto the terminal end.


----------



## Alaska (Jun 16, 2012)

Great post. Anybody reading this that is going solar/ wind off grid/battery back up this worth saving.


----------



## JeepHammer (May 12, 2015)

Alaska said:


> Great post. Anybody reading this that is going solar/ wind off grid/battery back up this worth saving.


Thanks, apparently you are the ONLY one that has read it! 

I keep trying to post on Series/Parillel strings and charging different age, size, type, capacity batteries, but the forum keeps rejecting the post...


----------



## Harry Chickpea (Dec 19, 2008)

I read it - or at least the first post, which made me wait to see if someone else would point out the errors. No one has, so I'll go at it.

"Current THEROY is the Positive will seek its polar opposite, which is Negative."

No. It is well established that the NEGATIVE terminal sheds electrons that then flow (or more accurately transfer the electrical flow) to the positive terminal. It is no longer theory and hasn't been for years.

One reason why this is important is corrosion. An example in action is that early cars had a positive ground. Over time it was recognized that they were more subject to rust and other corrosion than cars with a negative ground.

"You give that DC load a good Positive, but its usually a mistake to hook the load Negative to sheet metal and call it a 'Ground'.

Your load/appliance will work MUCH better if you give it a solid Negative path back to the battery, 
Mostly since steel and cast iron are HORRIBLE conductors of DC current.
Steel is high resistance, cast iron is very high resistance and cripples the full connection of the DC circuit."

Bullpoo. This shows a total lack of understanding of electrical concepts. As an example, early trolleys used an overhead of about 600 VDC. There was no dedicated return wire at all. What there was in its place were copper sheets buried in swampy areas near the power station, and grounding along the tracks. The power went through a "fuel" wire, to connections with the "trolley" wire, and then through the motors and resistors to exit via the trackage and then to ground and the soil, which returned the power to the station. If you think steel is a poor conductor, ground is far worse. The difference is there is a LOT of ground compared to a comparatively thin wire.

The differences in electrical resistance over short distances is miniscule, literally less than an ohm in something the size of a vehicle. Resistance is also reduced through the increase in surface area. When you run a significant amperage through a wire, the wire heats and the resistance increase to a balancing point or the wire melts apart. When you ground to the frame of a vehicle, the increased surface area and heat dissipation more than compensate for any imagined difference in resistance.

If you are grounding through a surface that itself has weak electrical bonding, such as joints and bolts carrying the current, then there is some substance to your claim.

Post 2 - terminals and wire ends. Simply crimping wire in an end - especially if the wire is a metal dissimilar to the terminal - will result in minimal contact point between wire and terminal, heating of the contact point and often corrosion. With old terminal connections it is more common to see the wire corrode away from the terminal connector than the terminal connector have a weak spot where it is flattened. 

In any event, the terminal connector is limited by the surface interface to the terminal itself, which is why corrosion often occurs in that hidden area between the connector and battery post, and why terminal brushes to clean the clamp interior surface and post were invented.

The posts after that seem fine, and I am in total agreement about proper soldering and the techniques explained. One missing point though is that the reason for solder at terminals is not as much to increase the electrical flow as to minimize corrosion due to the electricity, heat, and presence of oxygen, moisture, and in some cases vaporized battery acid. In fact, when 4 ought is terminated at a trailer pole or home electric entrance, no-ox is used instead of solder. By preventing the oxidation, the crimped connections remain adequate to cover substantial current. It works some in battery connections, but not anywhere near as well as proper soldering and then sealing of the soldered connection.


----------



## JeepHammer (May 12, 2015)

Harry, 'Theroy' was specifically used.
Its known by electrical geeks that electrons flow negative to positive,
Early experimenters were gauging 'Holes' where electrons were missing in orbits.
They were seeing reaction, not the action of moving electrons.

For every action, there is a opposite and equal reaction.
Electrons move one way, voids or holes move the other.

'Common Electrical Theroy' doesn't have a lot to do with actual electrical practice anymore.
Too may years of overlap in terms between AC & DC,
Too many myths, 
Too many long standing fallicies that have never been cleared up.

-----

The reason Positive Ground fell by the wayside was corrosion,
But not why you wrote,
Ionization was the reason...

---

As for electric trains, 
High Frequancy DC was used, and still is in many cases.
Partly Armature Rectified Pulsing DC current from DC Generators (NOT ALTERNATORS).
Mostly because you can't push DC through long runs of wire without building substanisal resistance.

There is a reason the Brown & Sharp Scale from 1889, revised 1903 is still the standard for DC, and why aluminum or steel wire isnt used for DC.

Oxy-Guard is for aluminum wires, not needed or recommended for copper.
Aluminum wire is no longer allowed in homes because of its tendancy to corrode,
Expand & contract deforming in terminals, creating more resistance and starting fires.

Aluminum wire is still allowed on outdoor long runs of wiring,
Only with AC, like from power pole to outside meter, and if you use properly OVESIZED wire so its resistance doesn't build heat,
From meter to breaker box.
Aluminum is strictly prohibited for use as interior wiring.
And aluminum is rated for Low Frequancy AC only.

Also, you missed the point,
With the losses when using batteries in a system,
Plugging up the leaks, stopping the hemmorage somewhere...
Panels aren't super efficient, quite the contrary,
Batteries can waste up to 40% in heat during chemical reactions of charging & discharging,
One way to stop the line & battery losses is the most efficient COMMON conductors,
And making sure your terminals/connections don't further lose your production...

Undersized cables heat up, wasting your production as heat.
Same with bad terminals/connections.
The same would be true with steel or aluminum conductors,
Since they do a lousy job with DC.

Its been a standard since the practical use of electricity to simply use a thermometer or pyrometer, later infra-red to detect bad connections,
To determine if wire gauge size is too small, ect.
Since electrical resistance builds heat, its pretty easy to use that heat to find high resistance.

A simple hand held infra-red pyrometer will often tell you when you messed up the wire gauge sizing, screwed up a terminal end, ect.
(About $20, runs on a 9 volt battery)

------

PS...
Since I'm NOT a trolley expert, I just looked up trolleys...

Turns out, trolleys using DC have TWO wires overhead, Positive & Negative...
Spaced about 3' apart.
A rebuilder company web site that refurbishes the drive motors & electrical components lists the motors with both positive & negative connections, and the overhead wire contacts are listed as positive & negative.
Apparently they use different materials for positive & negative contacts with the power cables.


----------



## JeepHammer (May 12, 2015)

I would say the next step is sizing battery string cables.

On a single string, the cables simply have to be as large as the Inverter mains.
The entire load for the inverter will be drawing through the battery string,
So the cables have to carry that entire load.

When you use TWO battery strings _IN BANC_,
Batteries wired in series for Voltage Increase,
Then the Two Or More Strings wired Parallel to the Inverter Mains to increase Amperage/Amp Hours of reserve,
The battery strings can be wired with smaller cables that are MUCH easier to work with.

Inverter Mains are often stationary, mounted solidly to your structure.
The battery string cables jump from one battery to another,
And you MUST rotate batteries for even charging/discharging in the strings,
You MUST clean terminals from time to time,
Having smaller gauge cables helps keeps things manageable.

Again, Rubberized insulation & Fine Strand cables make the cables more flexible, easier to work with.

ALWAYS HAVE HIGH QUALITY EYE PROTECTION ON WHEN WORKING WITH BATTERIES!!!

Batteries can be dangerous!
Use a fan blowing over the batteries, dissipate the potential for explosive gasses,
Watch power tools around batteries, they produce sparks internally that can be an ignition source,
Use Heat Shrink or plastic dip on tool handles, exposed conductive surfaces of the tools.
A cheap modification that keeps accidental 'Shorting Out' from happening.

If you wear jewelry, rings in particular, its a good idea to take them off.
I've seen more than one cooked finger from wrench/ring/accidental short out while working on batteries, and 1,000 amps causes serious damage QUICKLY. 
If you are going to grill meat, do it after you are done with the battery work, not during...


----------



## JeepHammer (May 12, 2015)

Now, with safety disclaimers in place...

You MUST use large enough cable feeding the inverter,
To feed that inverter under full load,
WITH A SAFETY MARGIN.

If you have more than one battery string supplying the Mains,
Then you have reduced the load any one battery string will have to produce to supply the inverter.

The example is the largest draw you will most likely ever run into just for sizing demonstration purposes... 24 Volt Strings Feeding A 4,000 Watt Inverter...

4,000 Watts + 25% Safety Margin = 5,000 Watts.

5,000 Watts Divided by 24 Volts = 208 Amp Capable Main Lines from batteries to Inverter.
208 Amps Require 00 Ga. Cable (2/0 Ga.).

The 2 or more battery strings will be SPLITTING the load,
208 Divided by 2 Strings = 104 Amps from each String.
That's a 3 Ga. Cable Size minimum.
3 Ga. Is a ton easier to work with than 2/0 Ga. Cable!

You could, in theory, continue along those lines,
5,000 Watts Divided By 4 Strings = 52 Amps Requiring A 7 Ga. (Or more common 6 Ga.) Cable in the battery strings...

The problem with Practical Application over 'Theory' is 'S**t Happens' in the real world!
'Theory' never has corroded connections, terminals coming lose, batteries in one of the strings failing, ect.

The Practical World Application, that stuff happens all the time!

The more strings you get, the more connections, batteries, ect there are to fail,
And a failure dumps that inverter load right back on the other string or strings...
So sticking with HALF inverter load as a general rule will save you aggravation/failures.

Especially with an off grid system...
Breakers will usually save your system when installed correctly,
DC breakers are often NOT installed correctly or aren't correctly sized/placed on the DC side of things...

If you build in extra amp capacity in the first place, your system doesn't shut down,
Just draws on the properly connected batteries harder,
In an off grid system, this often means no interruption in service.

Keep in mind, this entire thread is aimed at getting the MOST out of your system...
If the system crashes, you aren't getting anything out of it!
If your system is crippled, you aren't getting the most out of it!

Building in a little redundancy, and safety in the 'Front End' saves you a ton of headaches for years to come!

-------------

Higher Input Voltage From The Batteries Reduces The Cable Size.

The same 4,000 Watt Inverter, Running On 48 Volts,
4,000 Watts + 25% Safety/Losses = 5,000 Watts.

5,000 Watts Divided by 48 Volts = 104 Amp Mains To Inverter.
That starts you out with 3 Ga. Main Cables Carrying The Same Amount Of Power To The Inverter...

Battery Strings DOUBLE in size, from 4 Batteries to 8 Batteries Each...
So there is a trade off no matter how you go about this,
There is no 'Free Lunch'...

That also puts more batteries in the 'Middle' of the strings,
So rotation of batteries is even more important!
Again, No Free Lunch...

Again, with more than one 48 Volt battery string, you can reduce the battery string cable Amp Carrying Capacity by 50%.
104 Amps Divided by 2 Battery Strings = 52 Amps, Requiring No Less than 7 Ga. Cables.
(6 Ga. Is more common and cheaper, gives you a little better safety margin).

And Again,
No matter how many battery strings you have, I wouldn't reduce cable amp carrying Capacity below 50% of full inverter draw...
Again, redundancy & safety issues.

---------


----------



## JeepHammer (May 12, 2015)

This is all based on PURE, VIRGIN COPPER CONDUCTORS,
No Alloys, no steel wires, No Aluminum Wires,
Full conductivity Terminal Ends,
Properly Crimped & Soldered...

Mechanical Crimp ONLY corrodes, Expands/Contracts Loosening Up.

Solder Only can and will De-Solder, Especially if its a bad solder job or the wrong solder is used in the first place.

Mechanical Crimp, Followed By A Proper Solder Connection,
Then sealed for Environmental Protection will give you years of trouble free service with reduced maintenance... 

-------------

Some Tips...
Cracking Insulation is NOT the end of the cable!
'Lug' Terminals ('Rings' or 'Eyes') can have Heat Shrink Tubing slipped over them,
Tubing moved into place over the cracks, and shrunk into place sealing up your high quality cable for more years of service.

When you cut cables to length, leave about 4" extra cable into the run you are cutting.
This will allow you to cut off the terminal, cut to clean cable, and install another terminal end to give your copper cable new life.

No matter what some 'Jack Hole' tells you,
NEVER, EVER USE 'FORM-A-GASKET' AROUND COPPER!
RTV Gasket Maker contains ACIDS as a curing agent!
Acid will go to work on your expensive copper and ruin it.
Doesn't matter what color it is, if it smells like vinegar, its acidic, DON'T USE IT!

DO NOT EVER PUT ANYTHING BUT DISTILLED WATER IN YOUR BATTERIES!
Not even 'Rain' water!

Batteries are usually 'Happiest' between 45*F. And 70*F.
For those in cold climates, insulated battery boxes that can open up to reduce heat when its warm...
A heater is rarely required, most of the time the charging/discharging heat produced will keep batteries from freezing in an insulated battery box,
But I suggest you build 'Summer Vents' into your battery box.

For those in warmer climates, IGNORE the diagrams showing batteries packed right together in battery boxes,
Space your batteries about 4" apart so heat can rise away from the batteries,
And batteries raised up so air can ventilate under them will also help them live much longer.

Next chapter, myths on charging batteries,
Dis-Similar batteries in a string together, old Vs. new batteries together,
Different types of batteries together...
What you CAN, and CAN NOT get away with.


----------



## Alaska (Jun 16, 2012)

Keep it up Jeep.
I have been off grid wind and solar for 8 years and have learned a lot the hard way. I was lucky to run into a smart solar installer who has helped me upgrade to a safer and more eficient system. At first I thought he was nuts with the size of wires. Now I work with him and learn something everyday that I do.


----------



## JeepHammer (May 12, 2015)

Alaska said:


> Keep it up Jeep.
> I have been off grid wind and solar for 8 years and have learned a lot the hard way. I was lucky to run into a smart solar installer who has helped me upgrade to a safer and more eficient system. At first I thought he was nuts with the size of wires. Now I work with him and learn something everyday that I do.


Is what your veteran installer doing about the same thing?

Do you or him have any objections?

As much as Harry wanted to argue, he didn't dispute one single thing about wire gauges, grumbled a little about terminal, but actually verified what I've found to be true, mostly the hard way!

Find a hot battery, he battery isn't happy,
Find a hot cable, the battery isn't happy,
Find a hot terminal, the connection isn't happy,
Find a hot electrical component of any kind, and its usually not happy...

My Temprature Gun is my constant companion...
I shoot EVERYTHING, note down 'Average' temps, Relative to ambient room temp.

The heat gun is cheap, simple, quick & accurate...
Finds batteries that are drawing too many amps, or there is a shorted out plates creating heat.
Its a quick check for connections that aren't showing signs of corrosion,
It verifies you have correct cable sizing, no heat under full load, the cable is sized correctly.

That $20 infra-red heat gun has saved more hours than I can count!

Its also handy for shooting the inverters, get a base line temp reading,
And an increase will alert you to a failing inverter before it goes completely out...

Its also REAL handy for checking on rectifiers, (wind/micro hydro)
Letting you know how close to the failure point you are running them,
And if you have enough heat sink on those rectifiers...


----------



## Alaska (Jun 16, 2012)

JeepHammer said:


> Is what your veteran installer doing about the same thing?
> 
> Do you or him have any objections?
> 
> ...


 We have not soldered the the connections but they are all of the correct wire guage and well crimped with shrink tube. The batteries have buss bars between them. I am now thinking I should put some space between them.
What brand heat gun? I will check amazon.
Thanks again


----------



## JeepHammer (May 12, 2015)

Heat Gun, For shrining tubing, Wal-Mart.
Temp Gun, I think it's 'Pyro-Master' or something, the label fell off a long time ago.
I've had several. 
Picked them up everywhere from the auto parts store to big box stores.

*"Don't solder anything you want corrosion in."*

That's my standard reply...
A good hard crimp is OK, but solder is the actual electrical connection.

YES... To the guys that will pop up saying that anytime two conductors are in contact, that is a connection...
That's true!

-- But for how long?
And how do you detect it when it fails?

Anytime there is a surface 'Skin' on metal, and you mash two of those surface skins against each other, 
NO MATTER HOW HARD,
Corrosion is going to happen,
Not 'IF', but 'WHEN'...

Dis-Similar metals are a guaranteed corrosion point,
Including plating on terminals,
Simply because galvanic transfer/corrosion IS going to happen when you put a current to it.

Now, SOLDER won't stop it entirely,
In about 500 or 1,000 years the solder will eventually corrode away exposing the conductors to corrosion,
But I won't be the one that has to fix it in 500 years!

And around strong corrosives (other than oxygen) like batteries, that solder stops penetration into the connection so the corrosives simply can't attack the copper directly...

If you don't COOK the insulation and heat shrink on assembly, overheat the conductors/terminals, the cable should last you a lifetime with some timely terminal changes.

I learned what the 1900s guys did, there was a lot of that stuff around,
The WWII era junk that I took apart all had silver soldered terminals,
Still in great shape, so if it lived for 70 or 100 years soldered with silver content solder,
Or plain silver if it was a high heat application,
Then it should outlast me without a ton of problems...

It's either TIME, or lack of background/education on the subject that leads most people to use crimps instead of soldering.
Crimps are much faster, mash and go,
But the big welders from the ship yards are all soldered,
All the power plant crap I've seen is soldered,
All the DC (Battery) cables from submarines are soldered,
In Commercial Aircraft, the ONLY soldered terminals are the battery terminals, and they hold up for 30 or 40 years at a time...

The wiring I did in the 70s as a kid on farm equipment is still holding up after 40-45 years...
And yet I mess with old 'Classic' cars and Jeeps, NOT SOLDERED, and the wiring terminals are falling off all over the place,
Simply rotted the cable inside the terminal end and gave up,
No heat shrink to protect the wires/cables, so they are all shot up about 3 inches or so...

All the while, 
The old MILITARY vehicles had soldered, sealed connections, and those harnesses are still working...
The company I work consult for has military contracts, and they require soldered harnesses on land vehicles...

It's a pain in the butt to solder/seal any connection...
It's also the difference between 10 years and 50 years of trouble free service...


----------



## JeepHammer (May 12, 2015)

Now, This *SHOULD* give the basics in a graphic for battery connections...

Series, Parallel, Building Battery Strings...

http://www.civilianjeep.info/PVPower/PVBattery01.gif

PAY PARTICULAR ATTENTION TO THE PARILLEL DIAGRAM,
Notice the Positive & Negative cables attach from different ends of the battery string?

Electrical current will 'Seek' the path of least resistance,
If you connect BOTH of your cables to the 'First' battery, both connected to the same battery at the end of a Parallel string,
The charging/discharging will draw on the FIRST battery harder than the rest of the batteries.

The 'First' battery is the path of least resistance...

Simply by moving one cable to the 'Last' battery, you will get a much more even charge/discharge when the batteries are active.

---------

Also, in Parallel, you CAN use mismatched battery sizes in very small strings,
NONE of the mismatched batteries in a parallel string will live very long,
But it gives you the opportunity to make power if mismatched batteries are all you have.

You can expect a only 25% to 50% 'Normal' service life out of mismatched battery sets, sometimes even shorter, depending on the degree of mismatch.

---------

MISMATCH IS THE #1 KILLER OF BATTERIES after using the wrong 'Water' to top them off!

A 'Weak' battery will DEMAND MORE CHARGING, while NOT producing it's fair share of current when you draw off the string.

The 'Weak' battery will DEMAND more charge from the charger,
And the batteries around it will be OVER CHARGED, cooking the 'Strong' batteries in that particular string.

While the 'Weak' battery will still test 'Good' the rest will become junk,
And a lot of people don't understand that, try to REUSE the 'Weak' battery,
And kill new batteries placed next to it...
This is a vicious cycle that will cost you a ton of money until you figure it out.

'Weak' batteries in a string with other 'Weak' batteries are fine, the string will produce power, a 'Weak' battery IS NOT useless,
But you can't leave it in a string with higher performing batteries.

Your batteries will need to be LOAD TESTED on a regular basis, usually monthly,
And the batteries that aren't evenly matched removed and paired with batteries that are the same charge/output compatible.

---------------

HEAT!
Your batteries will undergo chemical change depending on temperature.
Ideally, batteries are 'happiest' between about 45Â°F. and 70Â°F.

People think of a Battery as 'Simple', but it's far from simple...
This little battery has the ability to take in Electrical energy,
Convert that electrical energy to Chemical energy,
Store that chemical energy for a fairly long duration of time,
Convert that chemical energy back into electrical energy,
And repeat the process hundreds of thousands of times,
Without completely charging or discharging, it can stop discharging at any point, and recharge...

When you think about most chemical reactions, there is no electrical component involved at all,
Most chemical process go one direction, once the reaction starts, it continues until all of the available chemicals are consumed before stopping.
Most chemical processes are one way, they don't stop and turn around 180 degrees and go the other direction...

This is a truly remarkable combination of chemical/electrical processes that is VERY finely balanced,
And yet will take tremendous variations & abuse...

And all you have to do to maintain this wonderfully complicated electro-chemical system of events is to keep CLEAN water in the cells, keep the top of the battery CLEAN, and keep that cell from freezing solid or overheating!

HOT WEATHER, HEAT VENT THE BATTERIES!
Space them apart, heat rises and is replaced from below by cooler air.
Simply provide a place for air flow UNDER the batteries, 
Space them about 4" apart, and let heat rising to do 90% of your cooling to keep that battery happy.

Efficiency goes WAY DOWN when batteries heat up,
It takes more charging to get them up to full charge,
When internal resistance rises, the batteries are less efficient at releasing their stored energy to you...

In older times, people had 'Well Houses' or 'Spring Houses',
A 'Well House' was usually sunk into the ground to keep the well pump/pump head from freezing up,
But worked equally well to keep the temperature DOWN from the sub surface cooling from the ground.

A 'Spring House' used cool water from a spring, circulated around milk cans or whatever, to keep the temperature down.

If you don't want to expend electricity to do climate control on your batteries,
Then consider letting the ground do it for you, FOR FREE.

One REALLY easy way to help cool in the summer, warm in the winter is vines.
Yup, growing vines planted around your battery box.
Vines grow in the spring, cover your battery 'House' or box, and help shade it.
BE SELECTIVE WHICH VINES YOU PICK, they MUST die off in the fall/winter to work correctly,
And they MUST NOT take over the yard! (Ask me how I know that! :grumble

.....

IN COLD CLIMATES,
Keep those batteries packed together, they will usually keep themselves warm from internal resistance while charging/discharging.
One thing about a solar system, the batteries are ALWAYS charging or discharging, so internally produce resistance heat can be put to good use.

If your batteries are susceptible to freezing, or get much below 40Â°F. then consider an INSULATED battery box,
But don't forget there MUST be air flow in that box to vent potentially explosive gasses.

IN MODERATE CLIMATES, where you see both hot and cold weather,
Then consider a battery box with latches/hinges on the sides, and vents built into the bottom.

Simply crack the insulation open and let it fold down, and open the vents on the bottom in the summer.
This was pure genius the first time I saw it, and SO SIMPLE it had never occurred to me before...
I've done it several times and it works WELL, is cheap, and takes no particular skill set to do...
Simple rough carpentry with commonly available materials...

------------------

I'm a machinist & lay electrician by trade...
My well is 6 feet from my batteries in an outdoor 'Utilities' shed.

We have 100Â°+ Summers, we have winters that can see -20Â°F. 
That's quite a range during the year!

What I'm trying now is a 'Spring House' with spaced batteries in metal (Stainless Steel) tubs.
The batteries are spaced apart in the summer, and the tub allows cool well water to circulate around batteries in the summer, when I have power to spare.
Not full time, but every couple of hours on a timer that circulates in cold well water...

In the winter, I drain the tubs, push the batteries together, and stick insulation around them in the tubs,
I also insulate the bottoms/tops to keep the batteries warmer.
The tub becomes the insulated battery box.

Not everyone will be able to do this, and I don't even know if it's going to make the batteries live longer, it takes between 8-12 years to tell if this is going to dramatically increase the battery life.
Just something I've done with two strings to see *IF* it's worth the time/money/effort to do...

My primary cooling/warming system is buried flexible plastic drainage pipe.
Large diameter, so the incoming air out in the field has plenty of time to warm or cool underground,
And a small fan to circulate air when the temperature in my utilities shed gets too high or low.
It's mother earth at work for me, cooling in the summer, warming in the winter.

The vent is buried about 8' deep, runs for more than 100 yards, has a 'Critter/Rain' cap out in the field, and has a screen/fan inside the building where it comes up from underground.
Keep the utilities shed fairly pleasant most of the year since ground temp runs between 55 & 63 degrees F. year round,
But volume can be a problem with the little energy efficient fan.

Heavy insulation in your battery box or battery room is recommended...
Along with adequate ventilation!


----------



## JeepHammer (May 12, 2015)

THIS SHOULD HELP EXPLAIN THE MOST SIMPLE VERSION OF SOLAR PANELS CHARGING BATTERIES...

http://www.civilianjeep.info/PVPower/PVBattery04.gif

This is the most simple you can get for RELIABLE back up power,
Or small scale Solar/Battery Off Grid system.

This is how most of the 'Power Carts' are wired,
Something on wheels you sit in the sun to charge in the daytime,
Then provide some short duration power supply once the batteries are charged.

There aren't enough solar panels shown to do much, but once the batteries collect the power and 'Bank' it, you can draw that power fairly rapidly to get some work done.

INVERTERS ARE NOT SHOWN.
Not everyone will use inverters to make 120 Volt AC power,
And with this small of a system, the batteries won't last long when trying to operate high drain appliances.

THERE ARE NO CHARGE CONTROLLERS!
Anytime the sun shines on the panels, they are charging the batteries.
The idea here is to keep the output from the panels low enough they 'Trickle Charge' the batteries instead of having a bunch of panels 'Blast Charging' the batteries.

The batteries live longer with a 'Trickle Charge',
Although it takes longer to charge, in an emergency situation, you wouldn't want to cook your batteries...
A multi-meter or volt meter connected to the batteries would tell you when the system was charging, discharged to the point you should STOP using it (So you don't discharge the batteries to the point of damage)...

This would be the MOST BASIC system for emergencies, relatively compact and easy to operate & maintain.
And it's the basis you will work with over and over again as your system increases in size & capacity.

As capacity and ability goes up with more panels, Inverters/Controllers, ect.
The basics will not change, but some minor wiring will change...
This gives you a basic understanding of how this stuff works.


----------



## JeepHammer (May 12, 2015)

Alaska,
I have used 'Buss' bars between batteries, sold copper, thick stock sheered into strips and drilled for connections...

The problem I have with a Buss in a battery bank, especially when people close those batteries up in a battery box with little or no ventilation,
Is the bane of any exposed copper... CORROSION.

I know this sounds stupid, and it's a lot of work, but it will significantly reduce corrosion in those high corrosion places...

I SILVER SOLDERED (not electrical solder) Pre '82 pennies to the buss where they would contact the battery terminals.
Then I cleaned/dipped the entire Buss in liquid vinyl, several layers deep.
Then CAREFULLY cut away the vinyl where the pennies were.

Pre '82 pennies are BRONZE, 92 to 95% copper, so they are very conductive.
Bronze doesn't corrode into copper oxide like pure copper will.
With the Buss coated in vinyl, it didn't corrode from acid/gasses.

I would NOT do this for anything other than direct battery contact or constant exposure to battery gasses, it's not worth the trouble...
When you run into that PITA corrosion issue, it's one way to use common materials to make a corrosion resistant contact without reducing the conductivity too much.

I got the idea from bronze slugs, spacers that I saw spacing the copper buss away from old time glass jar batteries.
Seems Edison had corrosion issues also...
They used asphalt to insulate the copper buss, with bronze spacers sticking out to make contact with the battery terminals.
I don't want to work with 'Tar', so it's either heat shrink or vinyl dip (like for tool handles) for protection of the copper.

I guess I could have 'Tinned' the copper, but again, that's a HUGE PITA to plate a large, custom made copper buss, and the vinyl lasts longer in a corrosive environment...

One thing I like about a coated buss, ELECTRICAL INSULATION!
Something accidently contacts the buss, no fire works unless it gets into the terminals...


----------



## JeepHammer (May 12, 2015)

LOW DOLLAR BATTERY DISCONNECTS...

A Battery disconnect should be on every STRING of batteries,
NOT JUST ONE for the entire battery bank...

Now, high amperage DC breakers are EXPENSIVE!
The housings are expensive, the breakers are expensive and can be a problem as you increase battery bank or capacity size.

This is a solution to the DISCONNECT part (not Fuse or Breaker part, that comes later).

These are 'Anderson Connectors', they are mostly used on high current fork trucks, industrial equipment, ect.
And they are all over the internet for cheap since they have been the DC high current standard for years...

Http://www.civilianjeep.info/Wiring/Winch/WinchInstall30.gif

Now, PAY ATTENTION TO THE UPPER RIGHT TERMINAL...
This is HARD CRIMPED, SOLDERED, HEAT SHRINK READY TO GO IN PLACE...
This connection is HIDDEN FROM VIEW, The more you can do to make it 'Bullet Proof' the less trouble over the long run you will have...

NOTICE THE BOLT THROUGH HOLES IN THE CONNECTOR TOP RIGHT & LEFT...
One side of this connector is MOUNTED SOLID,
The other has a quick yank disconnect handle on it.

There is your quick disconnect!
You will need to take battery strings off line from time to time, Maintenance, Testing, Rotating, ect.
This serves TWO functions, The handle is the Quick Disconnect. No questions ask when this handle is yanked *IF* a breaker actually took the batteries off line or not, 
You have tactile and visual confirmation the batteries are no longer connected to the system in any way.

REMEMBER!
Your 'Strings' will be connected to the inverter Mains, that is a terminal connection point.
You simply substitute this Anderson Connector for the more typical 'Lug' terminals/Stud or Bolt connection.

---------------------

BATTERIES ON THE BOTTOM HALF...
The LEAST number of wires/cables you have connected on the battery side of the quick connect the better.
Keeping small gauge wires/terminals AWAY from battery corrosion will dramatically extend the lifespan of those connections.

So with this system, you simply make the smaller wire connections directly into the UPPER half of the Anderson Connector,
Crimping those wires directly into the Anderson Terminals, running those wires through the heat shrink, boots, ect.

CORROSION PROTECTION FOR YOUR FANCY WIRING...

This is NOT a common practice, but it's VERY EFFECTIVE.
Not one speck of corrosion in my terminals made like this in over 10 years!

I fill the BACK SIDE of the Anderson Connector, and the BOOT for the Anderson Connector with Dielectric grease.

Keep this in mind if you are skeptical,
Where grease is, moisture, acids, vapors, not even oxygen can be. Grease simply leaves no room for corrosives of any kind.

http://www.civilianjeep.info/Wiring/Winch/WinchInstall31.gif

This shows a TUBE of Dielectric Grease, but there is dielectric grease in tubes (like calking) and aerosol cans with skinny tubes to get down in that connector with, filling from the bottom to top.

The biggest fire in a solar system I ever saw was from a roof leaking and running rain water down the cables right into the connectors...
This even seals out water when you use TERMIAL grease in the open end of the connectors, the connection is water/weather tight!
This is VERY cheap to do, takes YOUR time, but makes your heavy gauge battery string connectors BULLET PROOF!

--------------

These two sided, IDIOT PROOF Anderson Connectors come in all kinds of colors to designate what function they play in your system,
They come in sides from about 50 Amps to 350 Amps,
With the 175 Amp & 350 Amps the ones I use the most.

http://www.civilianjeep.info/Wiring/Winch/WinchInstall32.gif

Without Doubt, these make things MUCH more simple when you build your own system,
And they are VERY reasonable,
Every part is re-buildable/replaceable without having to buy the entire connector over again...

http://www.civilianjeep.info/Wiring/Winch/WinchInstall29.gif

I can't recommend the actual 'Anderson' brand enough, 
Some of the 'Knock-Offs' aren't nearly the quality of the actual Anderson brand...


----------

