Bad cell in battery

[Michael G]

I have a large industrial 12v battery, about the size of three car batteries, with a cell that only measure 0.4v while the other measure over 2v.  Is there any hope for it or is it junk?

[MelTx]

 Hello Mike.   The kind of batterys that are Usually have the soft tar around each cell.If it is the kind that has a hard ruber-plastic top cover it would be more trouble than it's worth.You can take them to a battery shop that does rebuilding,they might let you watch so you would know how next time.IF you are going to do it your self you need a tourch to melt the tar and remelt the lead straps.It is possible to swap a similar cell from another batt into the bad cells place.Watch for explosive gas! Huff & puff & blow the gas out before applying the tourch.

                                      Maybe this will help        MelTx

[Psycogeek]

a dead cell is a good indication that the plates have corroded so far, that its gone, you possibly have a shorting occuring in there.

Like is said above, the short can be removed, but i dont see much hope for the battery as a whole.

but with batteries like you guys are using, your sure to get something out of it.

analize its age, the number of deep discharges it has accomplished, and from that info determine if its worth the effort.  as soon as you toss it, it will be worth the effort to someone (for a while) :-)

[whatsnext]

Also you may just want to pull off the cap and look inside. It will be pretty clear if the plates are distorted eneough to short. If not, try some EDTA. You really have 6 little batteries strung together so the cell with the worst sulfation will get the least amount of charge. This is why multi cell batteries are kind of a waste. One other thing you could do is just to charge that one cell and see what happens. You'll need to find a 2V charget.

John..........