LifePo4 battery question

[Paul T]

I have the above mentioned battery in a 36v 20ah pack and its been sitting on my shelf for about 18 months I haven't touched it. Would it still be ok? I want to sell it but don't want to sell anyone a dud battery. It cost me like 900 dollars.
Thanks

 

[edventure]

I have the above mentioned battery in a 36v 20ah pack and its been sitting on my shelf for about 18 months I haven't touched it. Would it still be ok? I want to sell it but don't want to sell anyone a dud battery. It cost me like 900 dollars.
Thanks

First I would place a voltmeter on there to see if it is still holding a charge. Second, the LifePo4 chemistry is better to keep at 50 to 60% SOC "state of charge" for long term storage. I would guarantee even if the battery is still holding a charge some capacity has been lost. You would need to load it to see how long it can hold a charge before reaching its lower limit. I am sure you may find someone here on ES that may be interested, but they are not going to want to pay anywhere near the $900. You may be stuck with it, but there is a for sale section on ES where you could post and see what offers you receive.

Good Luck,


Ed

 

[Paul T]

Thanks for the info, I'll let it go for like 500 bucks, its pretty much new just hardly used
I just checked it cost me 1599 dollars goodness gracious...

 

[dnmun]

you can use your voltmeter to measure the cell voltage of each of the 12 cells in the pack. if it has been sitting for 18 months then you can expect that the circuit current for the BMS will have drained down the first 3-4 cells by now. so check that and we can walk you through how to deal with it.

 

[dogman dan]

Ouch. If you never charged it for 18 months, the bms has killed some of the cells, using them up to power just the bms.

Check the voltage of each cell, before you put it back on the charger if possible. There will still be a good 24v set of cells in there, so you can surely still get something for them.

You paid a lot for that battery, are they very good cells like A123's?

 

[wesnewell]

Thanks for the info, I'll let it go for like 500 bucks, its pretty much new just hardly used
I just checked it cost me 1599 dollars goodness gracious...

I'd say you pretty much got screwed since one can buy a new 20ah 36v lifepo4 battery pack for under $400 shipped.

 

[jimw1960]

It should be fine but easy enough to check. I also have a 36 volt lifepo4 former ebike battery that I only use about once a year to power some led Christmas lights. It holds the charge just fine all year. After a year of sitting, I plug in the charger and the green light comes on within minutes. I'm not sure what dogman is talking about because none of by battery BMSs draw any current when not in use.

Why was yours so expensive? Are they A123 cells?

 

[dnmun]

the guys is gone. i doubt if he will be back after getting insulted.

 

[Paul T]

who got insulted? I think the cells are really good quality hence the price, I hope. Thanks for the replies 8)

 

[dogman dan]

So what are they? You don't even say in your for sale thread.

I would expect most of the cells to be fine.