combining new with old LiPo cells?

[A RC Dude]

i had the 5th cell in my e-maxx to puff up becouse my balencer somehow turned off wile charging one time and it slightly overcharged. i can buy 2 new cells that are the exact same (minus the 25-30 chrages on them) for $40. would it be ok if i were to buy 2 new cells and wire them to the 4 i already have making it a 6s pack? or can you not combine new and old LiPo cells for some reason?

[jhautz]

Bad juju to combine old and new cells. The old cells are not as powerful as the new cells and will hit the low voltage cut off before the new cells except the new cells will keep the pack voltage higher and you will over discharge the old cells. Plus every time you charge you will likely have a pack that is pretty far out of balance.

My recomentation would be to turn your old pack into a smaller pack by removing thr bad cell/cells and get yourself a new pack AND a charger that can monitor all cells individually while it charges. Most modern chargers would have avoded the problem you are describing.

[A RC Dude]

ahh ok. well then i guess i'll just take the cell out of the old one and sell it. but i need i guy to re-wire it for me. ive forgetten the name of the guy who did it last time for me. i think i may have been lincpimp? or did i get the name wrong?

[E-Revonut]

LincPimp was most likely the guy that did it for you but he has since gotten out of the business of doing lipo repairs. You can always send him a PM and ask though. If he's not up to it shoot me a PM with what you have and what you want and I'll let you know what I can do. I have rewired packs for Rnemhard on here and I have done some for myself and fixed a pack for a guy at the track I race at. I'm not the expert that LincPimp is but I can do it

[A RC Dude]

thanks! i'll send him a pm and see what he says. i would do it myself but i never can seem to solder things well