I bought a 48v 17.5ah battery from a VERY shady seller in china. The battery case is a hailong shark pack. The one with 4 led indicators. The thing is that when I press the button to check how much battery I have left, all 4 lights are always green. I think there is something wrong with the BMS system, that it's miscalculating the voltage. Another thing is that the battery is draining very fast, I'm not sure if thats how it supposed to be or not. But it drains around 0.4-0.5v a minute when connected to a trainer with 0 resistance, ans PAS set to 1 on BBSHD. The shady seller, the indicators always being green, the battery draining so fast, it makes me worry my battery quality is crap and that the whole thing is gonna explode right under me. Are there any stories about ebike battery packs from china exploding?
Worried my battery is unsafe
- Thread starter mangekyo
- Start date
Sure, just look around the internet.
If the seller was shady, why would you ever buy from them? :?
Why not link the seller and the pack you bought, so other people can avoid them?
What does the seller say about the problems you've reported to them?
No way of knowing anything about your battery's problems, chances of issues, etc., until you begin testing it though. You'll have to open it up for most of that, and cut into the heatshrink if it has any, etc.
If you have a wattmeter, you can find out what the actual drain of the system is when on the trainer, to see if it's a lot more power than you think it is, which might explain the high drain rate.
The meter might have several possible reasons for always reading green. (fwiw, the BMS hardly ever has anything to do with that meter--the meter is typically a completely separate board). It might actually always be full, in the tests you've done so far. It might be just 4 LEDs (or one led with a plastic diffuser) wired always-on to power and not acutally a meter. It might be a meter meant for a 36v pack instead. Etc.
So the first test I would make is to use a wattmeter between battery and bike to find out the actual power draw.
The second I would make is to open up the battery and measure each cell group's voltage, both at rest and under various loads.
While it's open, I'd take good clear well-lit pics of the entire pack inside and out and post them in this thread.
The third is to examine the led meter board to see what it is, and test it with different voltage inputs to verify if it does indeed react to different voltages with different numbers of LEDs lit.
If the seller was shady, why would you ever buy from them? :?
Why not link the seller and the pack you bought, so other people can avoid them?
What does the seller say about the problems you've reported to them?
No way of knowing anything about your battery's problems, chances of issues, etc., until you begin testing it though. You'll have to open it up for most of that, and cut into the heatshrink if it has any, etc.
If you have a wattmeter, you can find out what the actual drain of the system is when on the trainer, to see if it's a lot more power than you think it is, which might explain the high drain rate.
The meter might have several possible reasons for always reading green. (fwiw, the BMS hardly ever has anything to do with that meter--the meter is typically a completely separate board). It might actually always be full, in the tests you've done so far. It might be just 4 LEDs (or one led with a plastic diffuser) wired always-on to power and not acutally a meter. It might be a meter meant for a 36v pack instead. Etc.
So the first test I would make is to use a wattmeter between battery and bike to find out the actual power draw.
The second I would make is to open up the battery and measure each cell group's voltage, both at rest and under various loads.
While it's open, I'd take good clear well-lit pics of the entire pack inside and out and post them in this thread.
The third is to examine the led meter board to see what it is, and test it with different voltage inputs to verify if it does indeed react to different voltages with different numbers of LEDs lit.
