How does one dismantle fork lift batteries?

[samson3000]

Last week, I purchased a used battery from an electric forklift.  It's 24 volt, and I  cut the middle lug so I have two 12 volt batteries.  Unfortunately, it seems I have 4 dead cells.  The voltage in those cells was about 0.5.  All the other cells were around 1.8V.  I was told it has been sitting, uncharged, to go to the recycler since New Year.  I charged each half for a  full day, and the same cells dropped back to 0.5 volts as soon as I removed the charger. The other cells came up to 2 volts.

Since I have 2 dead cells on each half, and not next to each other in those halves,  now I'm thinking I'll just make one 12 volt battery, but not in the metal case. I thought I could remove the dead cells from the metal case, but I have had no success.  And searching the internet has yielded no information. (Which really surprises me, because I found a couple threads on here talking about combining a couple used fork lift batteries to make one good one) Am I wrong in thinking it's a bank of individual cells?  I thought it was 12, 2 volt, individual cells.  And that they could be pulled out of the metal case. But is it actually one plastic housing inside the metal case? Or is every battery made different and I need to figure out exactly what I have?  The only reason I would like to get rid of the dead cells and the case is for room, since I will only be using 6 of the cells now.  But if they do not come apart, I'll just leave them in there and make jumpers.

[Watt]

I have a used battery bank that has two problem cells.  I took the top off one cell and found the positive lugs had separated from the main battery structure.  

To answer the best way I know how, I removed the lead buss bars from this cell.  I cleaned the battery group and posts. I removed the rubber grommets from the neg. and pos. terminals.  I then used a soldering gun with a self made heat tip and melted a line while at the same time adding thin wood to the melted plastic at the cap line.  Once the cap was free I gently removed and made my discovery.  

I have not fixed the battery but I do keep the remaining cells charged.  I bought a rebuilt or maintained battery instead of continuing the repair direction.  I just don't know how safe or practical a repair would be.  Once I realized sg had to be inline, I just sorta gave up and moved on.

Mike

[zeusmorg]

 In repairing a forklift battery, there are several ways to go about it depending on how it's built.

 Some are a series of 2 v cells, individual. Some you can open the top on and remove the plates and put them in a different case. I'd really have to see the thing to determine what is feasible. You may not be able to easily disassemble yours, It depends on how it is made.

 Even then it sounds like you got a bad one, you'll need specific gravity readings very close to each other to ensure proper charging.

[SteveCH]

Don't know whether this will help but:

Our house pv system charges a forklift battery set, 1860 ah consisting of six, 2v cells  in a steel box. In my set, the cells are individual and can be removed. The case for each cell is plastic, and there is a little bit of bulging in the sides because they are so heavy [if I recall correctly, my cells are around 330 lb each]. That means they are a bit jammed in the steel container. And therefore a bit difficult to remove.

I haven't had to remove any of mine. The dealer that sold them to me had a hoist device with which they could lift out cells or install new ones. I don't recall how it worked, it's been 18 yr. since I bought mine.

The dealer told me, however, that the cells were readily rebuildable. So, if some of yours are in good shape, that's an option. Rebuilding the bad ones, I mean. No idea what that would cost.

[SteveCH]

Don't see a way to edit these posts, so will add another item. I had my battery set delivered with the cells outside of the steel box. I picked them up in my pickup and didn't have a way to get them off the truck assembled, or well over a ton in weight. I did this so I could single-handedly maneuver them up steps and into my house and across the floor, etc., one at a time. I cut the front face of the steel box off with a torch, ground the cut edges clean, then was able to shove the cells into the box one at a time. I had no way to lift them up inside the house to lower them into the box. I put the front pc back in place and held it there with a pair of steel cables tightened up to hold the box in its original dimension.

Of course, one cannot cut off the front with the cells already in place. Or, it would be a hairy operation to try.

Anyhow, if I need to remove a cell, I can release the cable turnbuckles and hopefully pull the cell out.

[Ungrounded Lightning Rod]

Of course, one cannot cut off the front with the cells already in place. Or, it would be a hairy operation to try.

Very careful work on the edges of the outer case with a grinder or dremmel-grindstone?  In a location where, if a battery spills, there is acid in the metal case, or some cells short and explode blasting lead and acid all over, you don't take out your house or car or start a grass fire?

I'd start by looking into the proper method for removing and reattaching the cell links, first.  Try finding the manual that goes with the model of forklift battery you acquired.  It should tell you all you need to know.

At the worst you could figure out how to reconnect the best half of the cells into a single good battery and leave the rest lying around as dead weight.

[Ungrounded Lightning Rod]

By the way:  I do NOT recommend cutting open the outer case.  It's there for a purpose.

Get the manual and find out what the repair options are.

[bob golding]

i suspect what has happened is the dead cells have got sulphated and have swollen up. i have seen this happen with old ups batteries. if this is the case you wont be able to remove them. i would leave well alone.

bob  

[Disco Stu]

a while back we used to do it im assuming its the soldered lead buss bars, cos this is what im going to explain

to replace dead cells we would use a hole saw and cut out a hole about a inch dia this will release the link form the top of the post after doing this we would then remove the cell from the pack and fit in the new one then onto the dodgy part we would then remove all the lids off the cells and get the oxy in there  (oxy only no flame) to blow out all the residual gasses then would cover them all with a good few damp cloths or towels (we used leather) this way if there still happens to be any hydrogen left in there the cells might pop when the hydrogen ignites but the cell cant pressurise to explode... then we fit the new link or old one if its any good and use the oxy and accyt torch to melt some new lead into the connection and presto.

so go through through all your cells and record the cell voltages and specific gravity and pick out the best few and make a bank out of the best of them , depending on how big your battery charger it could take up to a week, and a bit more to give them a good equaliseation charge

stu