Replacing unavailable cells

[Telemachus]

Thanks to Amberwolf and Fechter, I have been able to isolate the problem with my BMS cutting out on a used E-Bike that I picked up last week.

One of the modules (7 cell array) drops below the LVC of the BMS when under load.

The battery is made of individual 22650 Li-Ion cells, rated at 2500mah, as can be see below:

https://endless-sphere.com/forums/download/file.php?id=220317&mode=view

These cells are pretty much non-existent. Any 22650 I can find are LiFePO4.

While I am confident that eventually I will have to rebuild an entirely new battery from better/newer 18650 cells, my goal right now is just to get whatever I can out of this current pack.

Could I get some suggestions on what the best recourse might be at this point?

1) Get some 18650 of slightly (or significantly) higher capacity to fill in the missing module, hoping that the higher capacity will compensate for likely better internal resistance of the newer cells?
2) Take one cell off each of the existing modules, and recreate the bad cell (although diminishing the capacity of the whole pack)
3) Keep looking for 22560 li-ion cells rated at 2500mah

 

[Hillhater]

Well, you learn something every day !
..I didnt even know 22650 li cells existed, but i now find these are located just up the road from me...
3.0 Ah but that is not a big issue......however the price may be !
http://www.ebay.com.au/itm/like/152566357740?dispItem=1&ul_ref=http%253A%252F%252Frover.ebay.com%252Frover%252F1%252F705-139619-5960-0%252F2%253Fmpre%253Dhttp%25253A%25252F%25252Fwww.ebay.com.au%25252Fitm%25252Flike%25252F152566357740%25253Fchn%25253Dps%252526dispItem%25253D1%2526itemid%253D152566357740%2526targetid%253D344559433199%2526device%253Dt%2526adtype%253Dpla%2526googleloc%253D9071774%2526poi%253D%2526campaignid%253D905534783%2526adgroupid%253D50700595652%2526rlsatarget%253Dpla-344559433199%2526abcId%253D1129306%2526merchantid%253D115560462%2526gclid%253DEAIaIQobChMIqa7_y-_z1QIVzAgqCh3JJgRBEAQYAyABEgJtV_D_BwE%2526srcrot%253D705-139619-5960-0%2526rvr_id%253D1293473006306&chn=ps&dispItem=1&ul_ref=http%253A%252F%252Frover.ebay.com%252Frover%252F1%252F705-139619-5960-0%252F2%253Fmpre%253Dhttp%25253A%25252F%25252Fwww.ebay.com.au%25252Fitm%25252Flike%25252F152566357740%25253Fchn%25253Dps%252526dispItem%25253D1%2526itemid%253D152566357740%2526targetid%253D344559433199%2526device%253Dt%2526adtype%253Dpla%2526googleloc%253D9071774%2526poi%253D%2526campaignid%253D905534783%2526adgroupid%253D50700595652%2526rlsatarget%253Dpla-344559433199%2526abcId%253D1129306%2526merchantid%253D115560462%2526gclid%253DEAIaIQobChMIqa7_y-_z1QIVzAgqCh3JJgRBEAQYAyABEgJtV_D_BwE%2526srcrot%253D705-139619-5960-0%2526rvr_id%253D1293473006306&ul_noapp=true

 

[Telemachus]

I really don't think they do exist any more. Jetson, the NY based company that retails these bikes in the US, says their batteries are not available until October so they are probably changing over to a modern cell.

I certainly am not paying that much for the 2 cells that they have... and I need 7.

Any problems you can forsee with using 18650 instead?

 

[fechter]

18650 should work fine As long as you can fit in enough to get the right capacity.

 

[999zip999]

How old is this battery ?

 

[Telemachus]

How old is this battery ?

Unknown age. Second hand.