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Cheap-E build. SLA to LiFePO4 not working. Need help.

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    Cheap-E build. SLA to LiFePO4 not working. Need help.

    48V 10AH. Total SLA build including bike and accessories - $450. Works great since 2019, however I'm going thru rear wheel tread every 2yrs, heavy to load in my SUV, plus I'm sure the cheap chinese bearings aren't going to last much longer. Saw on Amazon LiFePO4 batteries are now under $40 each, so I bought 4 and changed out the heavy SLA's with these. LiFePO4 batteries are same 12v 10ah. Each one was delivered over 13 volts. After installing, batteries showed 4 bars out of 5 on my battery monitor. As soon as I gave it some juice, bike stopped and battery monitor showed empty. I measured each battery and each one was still over 13 volts so I'm stumped. I'm guessing the BMS on 1 or all batteries can't take the load and shuts off? I put the SLA's back and everything works.

    Anyhow, is there a 12V, 24V or 48V LiFePO4 batteries under total of $250 that will work in an on and off road environment? I'd like to use four 12V in series. Thanks for any help.

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    Thanks for the quick reply stts. I don't know much about this stuff. From your info and others on this site, I guess the torque required for my cheapy application is greater than what these cheap LiFePO4's can manage so I'll return them.

    I don't want to be critical but shouldn't someone change the name of this website from "electricbike" to "electricmoped"? Seems a lot of people on this website never use the pedals, not getting any exercise.....soooo why have a bike? Why not just get a moped or motorcycle? I enjoy pedaling. I only use the 48V in strong winds, going uphill or crossing a busy road. I still have a little juice remaining after a 10 mile trip with my SLA's.

    I appreciate your help in deciding what to do. Thank you!


    • AZguy
      AZguy commented
      Editing a comment
      Outside of the sur-ron section I think a lot of folks are in the pedaling camp - some more than others... for me if the motor is making power I'm pedaling and I'm old and disabled... I'll go on runs with friends on their acoustic bikes and just leave it in PAS0 with no assist... I always like it when people ask what the "range" is on mine and I tell them it's infinite since I don't need to turn it on! ;-}

      Good luck with your project... not too many use LiFePO4's due to the weight and size penalty compared to the usual Li-ion chemistries most electric bike guys are using... but if you are coming from SLA they are way better... I think most folks consider the no-name chines stuff to be risky purchases... not to say there aren't some good ones but there's so much junk even if you are buying from china best to find a supplier with some real reputation IMO...