Sabvoton 150 cutting out under load

[boerhunter]

Hi,

Firstly I'm extremely grateful in advance for any advice.


My issue is a 72v 8000w stealth clone with a 150a sabvoton controller with Bluetooth. It worked fantastically, but I became severely ill and couldn't ride for 18 months (nearly died, so grateful to be here).

Now it turns on, charges, starts to run but if I accelerate it cuts out, flashing the motor/communication error (30h). To turn it back on it needs to be on charge then it will start.

I connected to it via blootooth via the mqcon app and it has good battery, hall tests fine etc. When raised I can gently rev up the engine and it will turn over quite fast but will cut out at full throttle. When I'm on it I can ride circa 7mph, then it cuts out after 30 seconds or if I accelerate.

So it's cutting out when the motor is under load.

All cables seem to be in good order, it was working perfectly before, battery shows good on phone and display, I've replaced the fuse for good measure but it looked fine. I don't know what the issue is as I'm new to this.

Once again, I'm sincerely grateful for any help

 

[E-HP]

What did you do, if anything, to maintain the battery during the 18 months you weren’t riding?

 

[boerhunter]

Absolutely nothing. I was bedbound, so it just sat there.

 

[E-HP]

When you say the battery shows good on the phone, is that via a Bluetooth BMS and measuring at the cell level? It sounds like some cell groups are low or weak so the BMS is cutting out.

 

[boerhunter]

When you say the battery shows good on the phone, is that via a Bluetooth BMS and measuring at the cell level? It sounds like some cell groups are low or weak so the BMS is cutting out.

Thank you, sounds a logical possibility. The battery shows full on the display and Bluetooth via the app. How would I go about testing or fixing the battery?

 

[E-HP]

You need to open the pack enough to access the BMS harness where the wires are used to monitor each group, and test voltages:

You may be able to try leaving the pack on the charger first, for several hours, in an attempt to get balanced, but I would monitor it while charging to be safe.

 

[boerhunter]

You need to open the pack enough to access the BMS harness where the wires are used to monitor each group, and test voltages:

You may be able to try leaving the pack on the charger first, for several hours, in an attempt to get balanced, but I would monitor it while charging to be safe.

I really appreciate your kindness taking the time to answer this.

 

[Maciek]

Simple test, connect voltmeter to your battery and see if it holds voltage under the load, when you accelerate. After long storage battery might still show voltage but can't deliver current due to increase of internal resistance. Real test of any battery is under the load.