Connecting charger with powered off bms problem

[chinzw]

When i connect the charger while the bms is powered off, the lights start flashing green very fast, and nothing is responsive. Using the switch or connecting the USB port gets the bsm out of this weird loop and turns on.

[raphaelchang]

This doesn't seem to happen on my board. Can you provide more details? What charger voltage are you using? How fast does it flash?

[chinzw]

Im using a 25.2v charger. It flashes about 4 times a second.

[raphaelchang]

Does the 3V3 power LED stay on? How does it flash (equal times on/off, quick flashes, etc.)?

[chinzw]

The 3.3v, the discharge and the () leds flash, chage and pwr stay on.

[raphaelchang]

Do you have access to an oscilloscope? 3V3 should not be able to turn off if PWR is always on.

[chinzw]

Im afraid I don't have access to an oscilloscope. If there's no battery connected it doesn't do this. Could this be because im using a 3s battery? Btw, the buzzer also makes some noise.

[chinzw]

I can record a quick video if that helps you?

[raphaelchang]

Video would be good. Try using a 6S battery (you don't have to plug in the balance connector).

[chinzw]

Here's a video, with 3s battery. Ill try with 6s tomorrow, its on my board at the moment and its quite late. https://youtu.be/xGqVGHwFxnc

[raphaelchang]

Try holding down the BOOT button as you plug in the charger (so that the code doesn't run).

[chinzw]

All 4 small LEDs light up when i do that.

[raphaelchang]

That's good, it's probably a code issue and not a hardware issue then. I'll take a look and ask you more questions later.

[chinzw]

Awesome, thanks for the quick feedback. Ill try and start reworking the balancing/charging algorithm if i have some time this weekend.