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  1. E

    What makes a cell group just die?

    I have a 14s6p battery pack and one p cell group is totally dead =0v. What makes a cell group die like this while the rest is totally fine?
  2. E

    Strange BMS issue

    I have a strange BMS issue. I change a bad BMS with a new one. The bad BMS outputs correct voltage, but as soon as it is loaded, it drops the voltage. The new one outputs 0.45v so something is bad with it. I change to another new BMS. I test the new one before soldering it and it outputs...
  3. E

    How do i solder this tab?

    I know I must be careful not to apply to much heat so I don't damage the cells. But I could attach something to cool the cell while soldering.
  4. E

    Strange issue. Changed BMS but didn't solve the issue.

    So i got a battery pack which would cut under load after 1-30 minutes randomly and even stop charging randomly. So i changed BMS and didn't do any good. I tried another charger and it didn't do any good. I even balanced the cells using the balance wires. All cells were quiet balanced but i...
  5. E

    20s battery pack reads very low voltage (20v)

    A friend has a 20s battery pack with BMS which he connected to some LED lamps. He forgot to turn off the lamps and ran the battery low, but not for a long time (like a few hours). Now it reads 20v. Wouldn't you think the BMS would cut-off of the voltage before something like this happens? I...
  6. E

    Ebike Battery pack got unbalanced. Reasons?

    I got an ebike battery with brand cells (MJ1) and after about 1000km of usage, the pack is heavily unbalanced. How can a battery pack all of a sudden get this unbalanced? I know it's a difficult question, but it could give me some hints :) The cell groups measure voltage: 3.13 (+) 3.12 3.06...
  7. E

    Discharge from the charge port

    I would like to discharge a battery pack to storage voltage from the charging port. I'm respecting the cable max current so I won't exceed the charge current rating when discharging. I think it's a BMS with separate C and P. So I guess I'm missing out the low voltage threshold shutdown but I...
  8. E

    DC Load test large battery packs. Rheostat?

    I have large battery packs, up to 60v@36Ah and output around 2000-3000w, which i would like to troubleshoot by loading them. I'm thinking a variable rheostat + Battery Coulometer...
  9. E

    Help me troubleshoot this pack please. How are these voltages?

    I have a battery pack (13s) that dies at around 45-46v (~40% capacity left) when loaded. I'm convinced (but not 100%) that I have one or more bad cells or unbalanced cells. Do you guys think I can solve this by charging it a very long time to balance any unbalanced cells?
  10. E

    Test a battery pack. How can i easily create a high amp load?

    I would like to put a load on a battery pack to troubleshoot it. How do you guys do this fellow forum members?
  11. E

    Using a 16s charger on a 14s battery pack. Will the bms protect it?

    If I ever did a mistake and used a 16s charger on a 14s battery pack, what would be the consequences? Would a some what advanced bms protect from charging over 58.8v? Because using a 16s charger on a 14s battery pack would charge each cell at around 4.8v which is not good at all. I wonder if...
  12. E

    Separate Charge and Load output on BMS. What are the differences?

    What are the significant differences between the Charge and Load outputs on those BMS that have that? Why would i want to use a BMS with different outputs for charge and load? Can i use the charge port as load and vice versa ?
  13. E

    Regenerative braking + fully charged battery

    I've seen many cases with broken e-bikes+electrical scooters when using regenerative braking on a fully charged battery. What is most likely to break in such a combination, fully engage regenerative breaking + fully charged battery, the controller, battery cells or BMS?
  14. E

    E-Bike "motor" rating?

    In most EU countries, the maximum motor rating is 250w for e-bikes and electrical scooters. Now is it that this motor rating is actually the combination of the controller and motor? If i use an electrical motor that can handle 2000w but i use a controller that does not output more...
  15. E

    Where can i get such a weldable Blade receptacle

    I'm trying to find such a weldable Blade receptacle but can't find anything alike. It is 2.8 mm and the material is either copper or nickel as it is weldable. I tried to weld a similar Blade receptacle made out of brass and it didn't go well :o I don't know if you can weld brass to batteries.
  16. E

    10s charger measures 42.3v. Bad thing?

    I bought a charger to a 10s battery pack and it measures 42.3 volts. Now that will over charge each cell a bit to 4.23v or will a good Bms kick in and stop at 42.0v? Should I be concerned? I'm the guy that usually charges to 3.8-4v to extend battery life.
  17. E

    Which Nickel strip size do you use for your 18650 packs?

    I would like to create a poll but it doesn't seem possible for me but i would love to hear what nickel strip size you use.
  18. E

    BMS that starts balancing at a set point/different voltage?

    Is there a BMS that can start balancing at any other voltage/setpoint than close to 100%? I only charge my batteries to about 80% but need to charge them to 100% sometimes to balance the cells. I want to avoid charging them unbalanced to 80%. Is there a BMS that can solve this?
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