18650 battery and regulation

[francoisboivin]

Hi everyone,

I am building a battery pack for my e-trike. I've bought a lot of brand new laptop battery (DELL 650) that are "samsung icr18650-26f" 18650 cell (72 cell in total). As they are new and already soldered in 3P configuration, I was thinking in NOT de-soldered them and do capacity test on the whole 3P pack. If there's a problem I will investigate.

So my final setup would be 12S6P for 44V@15.6Ah. The ICR18650-26f have a max discharge rate of 2C, which makes Imax=31.2A. I haven't bought a BMS yet.

I bought the mid-drive kit from sick bike parts, it comes with a 36-60V - 40A controller (non-programmable). (http://www.sickbikeparts.com/catalog/product_info.php?cPath=26&products_id=181 )

Q1: how can I limit the current used by the controller/motor so it doesn't go over 30 (to be safe)

I haven't figure how to charge the battery either.

Q2: From what I understood of all my readings, I just need to supply the BMS with DC current at Vmax and it will take care or the rest or am I misleading?

Q3: is it more easy to go 13S because 48V is a more common voltage and it's easier to find a power supply?

Thanks!

 

[Skalabala]

What I can add is that you are planning to draw to much currant

 

[francoisboivin]

yes that's what kind a figured out since then. Now i'm looking at the possibilities: either use the "3 speed mode" of the controller and disable the third speed or add a resistor on the throttle do decrease throttle voltage and therefore avoid going in the upper part of it.