Santacruz
100 W
- Joined
- Jun 18, 2015
- Messages
- 148
Hi all,
I am hoping I can get some help with the following problem.
I have a strange power loss problem with my set up. Apart from this, it is running perfectly and doing what it should.
The problem I am having:-
When fresh off the charger 90.2v (22s @ 4,1v per cell), I get maximum power. Drawing around 100amps I have about a 6v voltage sag.
Once the unloaded voltage gets to around 81v, then on riding, it is as if a limiter has been switched on. Max draw is about 30amps. Voltage sag is still around 6 – 8 v. Speed does not change, only acceleration.
It can be cured by charging back up to 90.2.
So it is a rinse and repeat cycle.
But I don’t understand what is causing it.
I would have thought I would still have good power draw down to my cut off settings.
My low voltage cut off setting in the Sabvoton is 66v, on the cycle analyst it is 68v and on my smart BMS is 60.2v. (2 separate stages to control power, before 3rd one by BMS cuts off completely)
Battery balance is near perfect, temperature are good. After running controller is cold, motor is cold, batteries are cold (Temp sense at 4 points).
Cell balance at charge / 0 – 0.002v
Cell balance at 81v / 0.013v
Set up:-
Battery, 22s5p 26650 5000mah cells. (Parallel connections 10mm x 0.2 nickel strip x 2)
(Series connections 5 x 2 of 10mm x 0.2 nickel and 4 x 10mm x 3mm nickel plated copper bars).
300amp smart BMS
400 amp shunt
Awg 6 silicone power wires.
Sabvoton 96120 controller.
Cycle analyst CA3 (set up to give a legal pedal only setting and 2 other settings for power) PAS works perfect on this set up.
Motor QS274 40H.
Runs smooth and quiet. Acceleration is very good. I get about 25km from fresh charge until the limiting appears. Even then, everything runs nice and smooth, the only thing noticeable is the lack of acceleration power.
Being in Netherlands, everything is on flat roads / cycle paths of tarmac.
I am hoping I can get some help with the following problem.
I have a strange power loss problem with my set up. Apart from this, it is running perfectly and doing what it should.
The problem I am having:-
When fresh off the charger 90.2v (22s @ 4,1v per cell), I get maximum power. Drawing around 100amps I have about a 6v voltage sag.
Once the unloaded voltage gets to around 81v, then on riding, it is as if a limiter has been switched on. Max draw is about 30amps. Voltage sag is still around 6 – 8 v. Speed does not change, only acceleration.
It can be cured by charging back up to 90.2.
So it is a rinse and repeat cycle.
But I don’t understand what is causing it.
I would have thought I would still have good power draw down to my cut off settings.
My low voltage cut off setting in the Sabvoton is 66v, on the cycle analyst it is 68v and on my smart BMS is 60.2v. (2 separate stages to control power, before 3rd one by BMS cuts off completely)
Battery balance is near perfect, temperature are good. After running controller is cold, motor is cold, batteries are cold (Temp sense at 4 points).
Cell balance at charge / 0 – 0.002v
Cell balance at 81v / 0.013v
Set up:-
Battery, 22s5p 26650 5000mah cells. (Parallel connections 10mm x 0.2 nickel strip x 2)
(Series connections 5 x 2 of 10mm x 0.2 nickel and 4 x 10mm x 3mm nickel plated copper bars).
300amp smart BMS
400 amp shunt
Awg 6 silicone power wires.
Sabvoton 96120 controller.
Cycle analyst CA3 (set up to give a legal pedal only setting and 2 other settings for power) PAS works perfect on this set up.
Motor QS274 40H.
Runs smooth and quiet. Acceleration is very good. I get about 25km from fresh charge until the limiting appears. Even then, everything runs nice and smooth, the only thing noticeable is the lack of acceleration power.
Being in Netherlands, everything is on flat roads / cycle paths of tarmac.