V10F wont charge behind 5*%

[FrenchUsa]

Hi guys,

I hope someone can help me. I have v10f for 2 weeks now with 100 miles on it.

Few days ago unit stop charging in the zone 50-60%, with power supply turned green.

What I did for troubleshooting:

1) My friend had v10f and i was able to charge is unit with my charger!

2) I looked voltage out of my power supply with voltage meter and reading 83.5 volt. To me it is correct voltage.

Now spoke with seller, he want me to try a different power supply (I don't agree is issues with power supply after my testing, anyway), ok I will but I am camping right now and trying to enjoy my ride. 

Now here my questions:

1) Can i looked inside and check cable connections? 

2) Would it avoid warranty if I open up v10f?

3) Should i try to drain voltage low enough (like 10%) and charge it?

One thing was weird, I left plug (plugged at 40%) in my charger for 24 hours (I know but trying something else). After 24 hours I was surprised to see unit dropped voltage from 40 to 23%, unplug and plug it back, few hours later was charged at 92%

Thanks for help!

[mrelwood]

If the charge stops at a lower than 100%, usually the BMS (Battery Management System, inside the battery pack) has stopped the charge to prevent any single cell group from going beyond about 4.25V. If a single group is trying to go too high when the overall charge is below 100%, it would mean that the other cell groups are too much lower in voltage. A small difference can often be balanced back by riding the wheel for just a few miles and then charging, repeating if needed. But if the pack stops at 50%, the difference is most probably way too large to be balanced out. Some cells would have been dangerously low, and charging them could even be a fire hazard.

 But a battery like that does not suddenly charge up to much higher and then be back with the issue. So it’s hard to say what’s going on. I doubt that there would be anything in the battery connections that would be visibly wrong.

 How’s the issue now? What kind of percentages have you been getting?

[FrenchUsa]

12 hours ago, mrelwood said:

If the charge stops at a lower than 100%, usually the BMS (Battery Management System, inside the battery pack) has stopped the charge to prevent any single cell group from going beyond about 4.25V. If a single group is trying to go too high when the overall charge is below 100%, it would mean that the other cell groups are too much lower in voltage. A small difference can often be balanced back by riding the wheel for just a few miles and then charging, repeating if needed. But if the pack stops at 50%, the difference is most probably way too large to be balanced out. Some cells would have been dangerously low, and charging them could even be a fire hazard.

 But a battery like that does not suddenly charge up to much higher and then be back with the issue. So it’s hard to say what’s going on. I doubt that there would be anything in the battery connections that would be visibly wrong.

 How’s the issue now? What kind of percentages have you been getting?

First thanks for you feedback, yes i head about fire hazard, I did a few little short ride, try to charge and still stop around 54%. I did multiple times, still same issues.

Seller is going to replace or fix (fix probably take a long time due to cell shortage in China). I still not sure what seller is going to do. I am very disappointing by the seller customer services at this time, is been a week!