What max current controller for 24v/7AH + brushed ?

[mer]

Hi all

I recently bought an e-bike with a 24V / 7AH NiMH battery and a brushed motor ( rated 24v / 180w ) but it is only PAS ( pedelec ) and I want to replace the controller with one that supports throttle . Now , Keywin ( e-crazyman ) sells two controllers , one with 21A max current and one with 29A max current . The problem is I don't know the max discharge rate of my 24/7AH so I don't know if 29A will be too much for my battery . The 24V/7AH battery is the classic cheap chinese pack ( let me know if you want a pic of the battery pack ) , these are most probably rated at 2C discharge rate ( D-size ? ) ? Or is it 5C ? If it is 2C then that means 14A so will it be a problem ordering the 21A or even the 29A max current controller ? I won't be riding steep hills for a very long time ... so I won't be discharging at 21A or 29A for more than a minute....

Thank you,
Kostas

 

[rkosiorek]

nimh as a chemistry does not usually support high discharge rates. 1C or 1.5C max is normal. 3C or 5C rates would reduce their life enormously.

for the sake of the batteries get the smaller 21A controller. on the other hand if you don't care about how long the batteries last get the 29A one for more power and more GRIN factor.

rick