low current issue that i don't know how to solve

rexey64

1 mW
Joined
Jul 10, 2021
Messages
13
hi,

i'm having a really weird issue with my scooter.
specs :

battery 72v45ah
two controllers 72v 50 a
4000 peak motors


when the battery is at around 70/71v, ( 3.5v per cell ) i can't seem to be able to draw any significant amount of current ( really low acceleration and max speed )

the thing is, i now know for sure it's not the battery, as i tried with another one.
i also tried changing the controllers ( with the same ones )

from 84v to around 74v, the scooters behaves as expected, with high acceleration and max speed.

i really don't know how to attack this issue. it can"t be the motors right ? could it just be a setting ?

EDIT :

in my display setting, i can switch between 60 et 72v battery. switching to 60v solves the problem. WTF ? does someone has any idea how this is possible ?
 
It sounds like the controller is going into "limp mode" when the battery voltage drops to a certain point. This is a common feature. Going slow is better than cutting off completely. But it doesn't make sense that switching to the higher voltage setting solves the issue. There may be a bug in the software.
 
The problem is solved when I set to 60, not 72v.
I edited my post, mistake on my part sorry..

But i Think you're spot on. The problem is it's not supposed to go to this mode until like 3v/cell. So there is probably a bug
 
rexey64 said:
The problem is solved when I set to 60, not 72v.
I edited my post, mistake on my part sorry..

But i Think you're spot on. The problem is it's not supposed to go to this mode until like 3v/cell. So there is probably a bug

All you did was move the LVC down, and the remove the protection. The feature is there to protect your battery, but if you intend to ever let it run it down to 3V, then I guess that isn't something you're concerned about.
 
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