Time to replace lipos?
 

Hey guys - been away from here for almost 2years (that's what getting married and having a baby do to your time). Have a little extra time so back no for a little more enjoyment of the hobby. :party:

Anyway - I've kept my lipos stored at about 50% and been checking and balancing them every 3-4 months. Even gotten a chance to run them every once in a while. They are all TP eXtreme 25/50C packs and they all appear to be coming up on about 2 or so years old.

There are 3 different flavors of pack, all 6S, which are 2600mAh, 3300mAh and 5000mAh. After a full charge the resting voltage of the packs is about 24.3 or so volts. This concerns me because the are CC/CV charging up to 25.2 volts - not sure if there is a danger there.

When running the packs the only reason I noticed anything is because I had the MMMs set to 3.3v/cell cutoff which worked fine when they were new. But in the past month the cars/trucks seemed to have no punch anymore. I dropped the cutoffs down to 3.0v/cell and that gave the packs their punch back.

When pushed peak amps for the 3300 and 5000 mAh packs is showing about 80-90A on the EagleTree and voltage is dropping down to 17.8-18. I'm sure if I didn't set cutoff on the MMM it would drop even lower.

Anyway - I've got replacement 45/90C TP G4 packs ordered - but I'm wondering if it's hitting the point of not being safe to run the other packs. After about 12 minutes of runtime batt/esc/motor are all coming in around 115-120*, but it's kinda cool out today.

Good question. I dont believe they ( old lipos ) will become dangerous or unstable as such, they just loose performance and will start running hotter- 2 years does seem to be about average lifespan which is one of the few things I dont really like about lipos ( having cheap lipos from places like hobbyking is nice though ). ~120 if fine temps wise, not much you can do really apart from monitor them and maybe use them in less intensive applications until such a time that they run too hot or power is so poor that they arent worth keeping..

Thanks for that info - kinda makes me question buying multiple pack the way I have done in the past or maybe looking into some of those less expensive packs.

BTW - has MaxAmps gotten any better in the past year or two or is Austin still blurting the same bs?

Well they went to using surge watts rating for all their lipos, what does that tell you. It tells me that they still want their batteries to look like the most powerful available, without telling you any good info about what they will handle.

:grrrrrr:

For some reason I'm not surprised..... I'll stick with my TP packs for now - never had one let me down short of aging.