About Li-ion Battery Packs

[Blackgolem]

I have this question about building Li-ion batteries, I'm just getting into electric mobile devices planning on making one for myself. I have a kids/adult Razor scooter that I'm trying to juice to get to local stores. The intention is to build a 10s4p battery pack but don't have all the 18650 cells just yet, my question is, is it possible to add just 2 sets of 10 cells to the 10s4p bms and run it that way until more cells are gotten? So I don't have to get a different battery management system. Any and all help is appreciated in advance Thanks.

 

[harryS]

Yes, it will work with just 10 cells. I never saw a BMS rated for the number of cells in parallel. It would affect balancing with a large number of cells, You might never be able to balance a 10S10P,

 

[Blackgolem]

Yes, it will work with just 10 cells. I never saw a BMS rated for the number of cells in parallel. It would affect balancing with a large number of cells, You might never be able to balance a 10S10P,

Hey thanks harryS 4 quick response this will make all the difference for me. Have a safe day bra and thanks again

 

[HansBr]

In addition to previous question, maybe also for HarryS. I have 2 battery packs 13s5p. One of them dropped from the holder 3 times, result of not locking the battery and very, very bumpy streets on Curacao. Power and capacity of the battery were much more low as a result. After charging I measured the voltage drops over 2 series, and on top and bottom of the pack. Top 8.28, 8.27, 8.27, 8.27, 7.37, 7.37 Volts. Bottom 8.28, 8.28, 8.27, 8.27, 7.82, 7.37 Volts. Conclusion, the BMS/charger charges till a little below 4.15 Volts (half of 8.28) for each battery, and the last series are not sufficiently charged. This can explain that upon discharging these batteries low voltage cut off is reached to fast (less capacity) and initial total Voltage is less than the 54 Volts (less power).
Then to my 2 main questions:
1) I suspect the BMS to be the origin of the mallfuncitoning, how can I check this is correct? Or, when it's not the BMS, what else can it be?
2) Can I combine my 2 batteries 13s5p till one grand total of 13s10p running on the (not broken other) original BMS?
Tips welcome! Would still love to go all around my Island, that's over 100 km.
Best regards,
Hans

 

[4936musse]

Yes, it will work with just 10 cells. I never saw a BMS rated for the number of cells in parallel. It would affect balancing with a large number of cells, You might never be able to balance a 10S10P,

Can you help me please, I have a 2000 wat real bike motor 72v.
I was thinking off Making 6 12v batterys off 18650 batterys with a balance bord, and then connect them. And then charge them separately. Can one pack be with like 3.7 volt and another pack be 4.2 volt
Will that be a problem.
Or all batteries has too have same volt like 4.2v

Bedst regards Poul Mortensen the Philippines