# Forklift Batteries question



## bobp (Mar 4, 2014)

I could potentially have access to forklift and pallet jack batteries. 12,24,&36VDC. We send several a hear out for recycling due to dead cells and various reasons. Actually sent one a few months ago because a contractor blew Grinder sparks over it while working on an upgrade, while it was charging, and it blew off 4-5 cells....however many cells were in new shape still. Often we scrap when they begin to lose cells, when for solar purposes I think a person could scrap bad cells only, rejuvenate the rest and use them? You can move cells from one to another to get good combinations I would think?

We run a fleet of 47 pallet jacks and forklifts, with 2 batteries for most, so they cycle out occasionally. We have a vendor that maintains them etc.

Opinions?


----------



## JeepHammer (May 12, 2015)

Industrial Steel Case Batteries are no where as efficient as the smaller cousins, but industry is used to 'Acceptable Losses'...
And steel case batteries are GREAT for beginners to mess with, figure things out, learn to 'McGyver' things until they work!

----------

Your best bet is to find industrial steel case batteries that have terminal damage...
The cells are still good, plenty of life, but the terminals are damaged.
Terminals are EASY to repair for solar power since you are drawing reduced amperage over a long period of time,

INDTEAD of drawing high amperage for a short period of time...

Drilling into an industrial battery terminal and inserting a stainless steel stud will usually do the trick.
Not very many solar arrays will draw more than a 3/8" stainless stud will transmit, just remember to drill at least 1-1/4" deep so you have enough contact area to transmit amperage from lead battery material to the stud.

You can also pour new terminals.
Clean off the lead as best you can, again, set a stud, then pour the new post around the stud.
I use a stainless pin instead of threaded stud when I do posts, you don't need the threads for attachment, so a plain pin made from a stainless bolt shank works fine and is cheap.

400 and better grade stainless (a magnet will stick to it) don't work as well as 'Food Grade' studs/bolts.
They are softer, but you aren't using them for 'Structural', they only have to take a nut tight enough to keep connection,
And the 'Food Grade (316) stainless lasts a lot longer exposed to the acid/corrosion.

As for cells, you CAN cut the bridges between cells, and theoretically remove the cell out of the battery, but I've never tried it.
Again, you will have to connect the old cells to the new cells, so again, you are back to drilling/tapping or pouring lead.

I think I would use some sort of stainless screen material in a bridge if I were going to try and rebuild that wide, flat bridge between cells, something for the lead to get a grip on as it makes the connections.

The issue I have with pouring terminals is having a heat source, usually a torch flame, that close to the battery cells,
You MUST make the old bridge/post lead molten before you pour your new lead.

It's a COLLASIAL pain in the butt to drain the acid out of an industrial battery so it doesn't off gas,
And it's difficult to push enough air across the battery to carry off the hydrogen and still be able to heat the lead to melting point.
Either the lead cools too fast or the flame won't concentrate where you want it to.
(yup, that's practical experience talking there! I've tried it, but I don't do it often,
And you see why the battery companies want to 'Back Door' anything with damaged terminals, they have the same time consuming issues!)

I 'Hear' (Haven't seen it done or tried it myself) you can use 'Cold Gas' to freeze the bad cell, pop it loose from the case, and then lift it out.
I can't imagine what commonly available gas/cooling you would use that didn't take a bunch of money or 17 layers of government approval/permitting to get your hands on, but supposedly works.

Personally, I used underground mining equipment batteries.
Steel cased, VERY high amp hour ratings, and got them for little or nothing.
I simply disconnected and jumped the dead cells and forgot about them.

With two or three sitting side by side, you can cable jump the dead cells.
The size/weight of these things, there wasn't any chance of them moving around and breaking my connections, so it worked just fine.
With them setting side by side, you can connect the cells via jumper to get ANY voltage you want, the cells don't have to be in the same case...
That's how I started out! Jumpers between two large steel case 48 volt batteries, got three sets of 24 volts by cutting bridges and jumping the dead cells...

Looked like something from a 'Rube Goldburg' drawing, but it worked fine for several years!

You can also break connections, RE-make connections to make TWO battery strings in one case.
A 48 volt battery can easily become 4-12 volt battery strings, or 2-24 volt battery strings.
In the early days, I had 48 volt batteries with 12 and 24 volt inverters/chargers, 
So I just broke the bridges at the 24 volt mark, installed studs, and run those batteries as 24 volts, ignoring the dead/disconnected cells.

Like I said, if you can find them for free or scrap weight, these are by far the best deal in batteries!
With external bridges between cells, you can do about anything you want with them and get away with it!
And when they fail, they are STILL worth scrap weight!
Nothing like getting something for nothing, using it for YEARS, then getting something out of it when it goes to the scrappers!


----------



## bobp (Mar 4, 2014)

The cells are indivually removable with simple hand tools. Bridging us done with strapping designed for the poupose. Our battery vendor swaps cells for us all the time. We use liberators.
I've seen us scrap them based on date codes. Still working but due to be replaced. Corporate rules etc.


----------



## bobp (Mar 4, 2014)

We also have the solder on connectors but the tubular cells are the same


----------



## bobp (Mar 4, 2014)

I can't help but cring over the brand new one that had the cells blow off. Over half were fine.


----------



## JeepHammer (May 12, 2015)

Sounds like you answered you own question!
The cells I worked with were stuck in with 'Tar', a real pain to get out.
That was many years ago, things change...


----------



## bobp (Mar 4, 2014)

My question was more to does anyone have experience using them? I suppose the hard part would be getting the APHs you need out of your charging system, hydro, solar etc...


----------



## JeepHammer (May 12, 2015)

Getting amp hours out is the easy part,
Getting the batteries to charge evenly is the trick.

Batteries that big, especially with 'Used' cells will charge unevenly.
I found charging them in 12 volt strings, while still drawing on the strings in 24 or 48 volts kept even old, mismatched cells operating/performing well.

No matter what the guys tell you, 
You CAN charge a 24 volt battery as two 12 volt units,
Or a 48 volt battery as 4 ea. 12 volt batteries,
While still having the cells wired in series for full voltage to the inverter.

You will need some diodes from Radio Shack, 2 ea. for about $1.50, so they are cheap!


----------

