Noob is stuck, noob needs advice

[Iamnotelectricallyminded]

Hi all!

I have a 48v electric scooter and recently I have sent my controller to a "highly recommended expert" here for modding. I was so happy when the controller was shipped back to me. After 2 hours+ of struggling, I have managed to replace my original controller with the mod one. Took it for a spin but had realised there was a problem.

If I gently applied throttle (Progressively), it would work fine. The power increase is significant. But the problem starts if I apply too much throttle suddenly, the power to the motor shuts out. I will have to release throttle and apply again (Gently) to move again. I have since written back to him to ask how/why/what can be done. His reply was "Bypass BMS or use a more powerful battery". No more replies came back from him since and I suppose customer service is dead from this point onwards.

Local scooter "experts" here have not been very helpful as well. One refusing to offer "troubleshooting" services but is more willing to do a full mod using all of his components (At a premium), and the other has actually suggested that I add on another battery and run it together with my existing battery and their BMS. I'm not particularly keen in this option as the thought of lugging another heavy battery with my small scooter does not go well with me. Also the costs are pretty steep for this option. They have said that their BMS with my lone battery, so a second battery is a must.

Besides reverting back to the original controller, are there any other options that I can explore? Many thanks in advance.

 

[jonescg]

What make and model of scooter is it?

 

[Iamnotelectricallyminded]

It's a Speedway 2. 48v 500w with a Samsung 18ah battery

 

[kdog]

Do you know anything more about your battery like cell type, also any info on new controller, bms will help. It does sound like a bms overload. Bypassing it with this current problem is likely to destroy your battery- the bms is tripping for a reason. Probly a low cell voltage under high drain. If so,your options are: to upgrade your battery (as in add more parallel strings ): change battery completely, ride gently ( may as well go back to the original controller), go back to original controller, or actually that's it I m out of ideas.
Have you got any idea of what you're drawing in amps- what was the controller mod?. does it happen at full charge or when battery is near flat?
Could be something else so investigate thoroughly before spending big bucks to find it was something else.
A battery upgrade might cost as much as a new battery so it could be costly

 

[eee291]

I once read somewhere about a modified brushless controller.

I believe he had the same problem and it turned out that the capacitor on the input wires couldn't handle the high current. So I suggest you reproduce this problem and then quickly open the controller and see if the cap is hot.