# new battery bank - first timer



## caridademoz (Sep 19, 2013)

I have read so many battery bank posts, but am just not getting all of the electrical specifics. I have started to collect the pieces of my new system, and intend to have someone who has more electrical experience put it together. BUT I'm quite remote and would like to have all of the components here before I get someone to come out.

So - 
I have 3 (three) - 200Ah 12V batteries for a total of 600Ah (AGM)
a 2000W pure sine wave inverter
a 75-Ah 4 stage battery charger
a 30 year old gas generator that I inherited. It is a 4000W.
currently have only 90W 12V solar panels, but going up to 225W shortly
the solar panels came with a charge controller (Harbor Freight with few specifications that I can find listed)

I understand that I should 'fuse' between the batteries and the inverter? What size fuses? Do I wire to a breaker box? I have a breaker box with the old vintage travel trailer which I'm remodeling for a home office and extra storage (I live in a micro cabin which I'm happy to not have wired, but would like to wire the travel trailer office to also have a small chest freezer and other small electronics.) I would like to also have some DC outlets directly from the batteries. Would that go to a different DC breaker box? Or would I fuse (what size) from the batteries and have them directly to outlets in the trailer? I think what I'm missing right now are the wires and fuses . . . I'm hoping that I can salvage the breaker box and some of the outlets from the travel trailer (though those things are probably also more likely to be available at the local hardware store than fancy large fuses.

advice on fuses and where I put them?

With batteries these large, I know I'm playing with serious danger/power. 

Thank you!


----------



## wy_white_wolf (Oct 14, 2004)

2000W / 12V * 125% = 208 amp breaker. Place it as close to the batteries as possible. 

With 3 batteries in parellel you also need to install fused interconnects. They should be @ 1/3 of the 208amp breaker.

WWW


----------



## Peasant (May 18, 2013)

Put a fuse or circuit breaker between the charge controller and battery bank, and in all the individual circuits you're running from your battery bank (one for inverter, another for DC loads)---put all of these as close to the battery bank as possible. Circuit protection is also required on parallel strings of 3 or more panels.

As to what kind of circuit protection, I'd recommend Midnite's circuit breakers. Bussmann also has range of 12V compatible circuit breakers.

Afraid to say, your sizing is off. 225W of panels is not going to reliably charge 600 ah of batteries. Assuming these are 12V panels, 225W will produce ~12 amps. This is a 2% charge rate for 600 ah of batteries, basically a trickle charge.

Your 75 amp battery charger is better. That's a 12.5% charge rate, definitely at the low end of the range when running it off a generator (I prefer ~20%), but acceptable.

2000W inverter is also fairly large for this battery bank. If you ran it at full capacity, battery bank would last for ~1.8 hours before it hit 50%. No load draw and inefficiencies at low draw might be problematic depending on your loads. What are you hoping to run off this system?

Harbor Freight is another issue. What components are HF?


----------



## Jim-mi (May 15, 2002)

Yes HF is for people who buy strickly by the price tag.
Their components are like a canary that goes----cheap cheap


----------

