Troubleshooting 48V 25ah lifepo4

[crawfojo]

Hey My friend
Were you able to resolve your battery problem I purchased the same battery as you 48v 25ah I am just at the end of the second season with it i bought it 2 July's ago July of 2014. I had problems right from the start and i had to set a bypass switch on the BMS it was cutting out way too soon 50v looking back at it now i suspect it was a bad cell. I have logged 3400 km on it. its performance seemed to gradually fade and now its pretty much useless i get about 8 km on a charge. I like the battery its very lite because it uses plastic pouch cells as apposed to the very heavy cylindrical cells.these pouch cells are fairly new ad d not know how proven this technology is. I think my problem may be a one off problem with a defective cell made worse by bypassing the bms.knowing what you know now would you purchase this product? have you herd of others with this battery manufacturer having any problems. Any info or advise on this item you have i would truly appreciate thanks

 

[dnmun]

why did you bypass the BMS? why didn't you fix it like this guy? it seems like all these sunthing guy 25Ah packs had the sense wires pull loose and if you had just fixed it then you would not have ruined the battery. i just don't get it. people always just say the BMS is broken with no proof and then bypass the BMS. i just don't get it.

 

[crawfojo]

it was bypass or trough it out in the trash I only by bypassed during discharge while in use. I would never let the total pack voltage dip below 48 volts and turned it back on while charging to ensure ballanceing. at the time I did not realize that one cell could dip below the magic damaging voltage level. Even with the bypass on and never going below 48v 3 volts per cell still well above the damage threshold it is most likely the one or 2 cells would be damaged not the whole pack.

 

[crawfojo]

anyways i am not convinced that the plastic pouch cell technology thee batteries use is there yet they are fairly new I could only source 1 manufacturer of single 3.2v 25AH prismatic pouch cells A 123 systems only manufacture the 20 ah pouch cell. i notice some other threads on this site where people believe the product they buy the 25ah 48v battery pack is falsely described because of the weight and package size they did not consider the new plastic pouch cells these use are much lighter then the metal cylindrical can cells. i am asking has anyone out there in the real world that have proven the longevity of these new cells the manufactures claim they are the same as any lifep04 technology

 

[bachmaninoff]

Sorry - I didn't get any notification that there were additional responses on this thread, plus I've been away on deployment.

This pack has been holding up pretty well. I use it almost exclusively to commute to and from work (40mi round trip with some decent hills). On my KMX trike I've put 2975 miles on it (per GPS), and on my E-Mongoose I've put 1087 miles on it (per CA). I've also racked up some mileage with it on my BikeE, but I don't have exact numbers for that (probably somewhere around 500). I have not run it to LVC recently, but maybe I'll test later. When I first received the pack I was getting just over 20ah (even though the pack was labelled 25ah).

At some point I'm planning on a dedicated battery pack per bike. But for now this pack is great.

Crawfojo - open your pack and take some pictures!

 

[999zip999]

We may be able to help fix and or balance your pack.