Flat battery charging

I have a Gen 2 Carbon. On a few occasions (maybe 3 times) I have accidentally run the battery dead flat until it would no longer turn on.
On these occasions the standard charger would not initiate charging.(Green light and wouldn't change to red)
I did manage to "trick" the charger into charging I think by powering on the board with the charger connected and running the motor gently.
The charger would kick in and and I had to repeat the process a few times before it would charge without doing it.
On probably two of these times I had also opened up the board and drained the capacitor etc by disconnecting the battery and pressing the power button etc. (I disconnected and reconnected motor cables and others but i think from memory in the end it was the power on trick that got it to start charging.

My board went flat while riding again last weekend and none of my tricks have worked this time.
The battery is reading only 30.7V with my multimeter.
I have the 30A fuse but don't have appear to have the small 5A fuse on the charging side of the BMS like is shown on the old pintail with similar looking innards in one of Jeff/Evolve how to videos.

Any help appreciated

 

sounds pretty bad.. for how long do you have your board? Did you buy it new?

For lipo 3.1v might not be that good :\

I think lipos can get damaged real fast when discharging too low.. u should probably check whenever BMS does his job and balance's the cells correctly.. for this you would probably have to tap into balance connector which comes from the battery and check each individual voltage with ''lipo alarm'' / voltage monitor..

These does not cost a lot (2-3usd, perhaps a bit more locally)
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Wont be able to give much other ''general advice'' as it seems like u should start inspecting your battery if you start to get this more and more often

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[Update]: Check this thread:

For Sale - [DE] Snubnose *custom-build*

He mentiones that older gen might not even have bms! (which is a bit crazy knowing lipos tend to drift apart more than li-ions, I think..)

Non the less. it looks like there's no easy way to get to each cell's terminals..

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My other ''useful'' advise would be connect the pack to some smart charger which lets you charge without balance connectors - check what capacity you get out of the pack.. that might perhaps indicate whenever the battery is worn out or not..

 

Thanks @okami762.653
I think I may have resolved my issue. Ill post back full details once confirmed for others in future

 

Hey @djgrazzy,

Thanks for sharing this, I have the same problem, were you finally able to resolve the issue? if so, can you post the full details?

Thanks,
Felix

 

felix, I ended up getting some info off evolve to measure the battery voltages individually so i could check.
When i opened the heatshrink on the BMS to check i found the white connector from the battery to the BMS was loose.
Plugging back in I got >40V and I was able to charge again. I added some fresh heat shrink and bobs your uncle.


attached is Evolves email and pic. I hope this helps
"
Hi Chris
Thanks for the email.
That voltage you have measured is extremely low, even for a flat battery. This could be as a result of possibly a reduced cell/s. This may be preventing the BMS from activating, allowing charge.
Can you please check if your BMS has the same points as shown in the picture attached.
You can test the individual cell voltages by testing the silver circles in pairs in the pattern below:
\ / \ / \ / \ / \ /
See if any cells are excessively lower than others.
Thanks
Nick
Evolve Skateboards Australia"

 

My BMS looked slightly different
pics of mine