I've reconditioned about 30 batteries so far, most of which seem to hold a reasonable charge. I've decided I'd rather wait for a possible future lithium-ion solution, so if anyone wants batteries, they can have them for the price of shipping.
All the batteries are loose, removed from their packs. They're all bulged to some degree, so much so that they only fit back into the metal band when I leave out the plastic spacers. Maybe one can be inserted into an existing pack of normal-sized batteries, but I can't say for sure.
If you're desperate for a battery and want to take a chance on one of these, let me know. I'm in Tucson, USA.
Are you talking about individual battery cells, modules, or entire packs? Are these just from a battery that wasn't kept charged while stored, or are they cells that have "blown" so that they overheated and melted adjacent spacers?
Did you use a CBA?
I would be very interested in cells with more than 21Ah capacity at 20A to 1V cutoff.
My weakest cell will soon be toast....
This information may be used entirely at your own risk.
There is always a way if there is no other way!
These are individual cells--I completely dismantled the packs. My range had fallen below the 20 miles I need for my commute, so I figured I'd rip it all apart and see if I could identify any obviously bad cells. None had gotten so hot that they melted spacers, but all are slightly bulged, as I mentioned.
What I've done with the 30 I've been through so far is to discharge them completely at 20 A with a CBA II--the first discharge normally takes very little time--charge them with 30 Ah at 5 A, discharge, then charge again. After this reconditioning, they'll put out between 25 and 30 Ah before falling below 1.05 V.
I've identified one unusable cell, which won't put out more than a couple Ah after reconditioning.
Great!
They are much better than my worst cells.
Would you be prepared to send them to Australia?
If yes, then let me know what number makes a cheaper packet size (depending on postage weight costs) and then you could send me packs of cells of that size with the postage cost "sweet spot".
This information may be used entirely at your own risk.
There is always a way if there is no other way!
thanks for the offer, at the moment my battery is still alive.
Jus wondering, when you say:
I've identified one unusable cell, which won't put out more than a couple Ah after reconditioning.
You mean that your mileage was highly decreased by only one bad cell?
I'm highly interested in understanding why a failed cell, which represents roughly 1% of all the battery energy, can reduce the range by 50-70%.
The vectrix diagnostics software diagnoses the battery at full charge or at empty charge?
If it diagnoses at full charge, a bad cell with a capacity of 2Ah can hold enough voltage to seem a normal cell? the diagnositc SW would tell that the battery is OK?
Mik,
How many do you think you'd want? We can arrange the details through private messages...
Ron
When one cell, connected in series, is damaged enough, it won't let through any power, even if all other cells are completely healthy. It becomes a great resistor.
I suggest you reduce the charge rate to 3A or less; at 5A you risk damaging the low capacity cells further. They could overheat and vent. The resulting pressure might also be more damaging than usual if the cells expansion is not prevented by the metal band.
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I considered continuing the project, and if that was the only bad cell, shunting around it, but then I'd be stuck with a marginal pack of NiMH cells and have the same battle with overheating in the summer. I'd rather just wait and hope for a brighter Li-powered future...
http://visforvoltage.org/forum/7834-shunting-damaged-battery-cells
I would like to obtain 10 cells. let me know what the cost to deliver them to the 20783 zip code in Maryland, USA will be, and I will send funds by "Paypal" if that is acceptable.==Bob Curry.
Robert M. Curry
Hello Ron,
If you still have any cells left, I would like to purchase 9 cells from you. If you do not have 9 left, please tell me what you have left (some are better then none). I live in New Jersey and my zip is 08087. Thank You for offering to help us guys out with bad cells. Take Care,
Louie