Battery full dashboard won’t stay on

[Mark Peddleman]

I’m fairly new to ebikes. 48v battery was stored indoors for more than a year and this year I tried to charge it but nothing happened. Charger only blinked red.
I read that if voltage too low the circuit inside shuts down and has to be awakened. No body would touch it and online info was complicated and dangerous. Someone here tried a trickle charger for a long time and his battery woke up enough so the regular charger now worked with a solid red light. Tried the same thing but with a 36v charger. After several hours blinking red changed the solid red and finished charging till all test lights on the battery lit. Then I put the fully charged battery on the bike expecting all to be normal.
Not quite. Dashboard will not stay on more than a few seconds. Pressing the throttle those few seconds the hub motor would run but only a second or so till the dashboard shut off. I wondered how it would be if I put the 36v battery on the 48v bike. Now the dashboard came on like normal but charge level showed empty and throttle would not get motor to run.
I’m at a total loss as to what’s going on and how to fix it.
I’m hoping one of you guys with more experience and knowledge can help.
Thanks for any helpful information.

 

[E-HP]

Your 36v battery voltage is below the controllers low voltage cutoff for a 48v battery, the controller will not operate. If it’s fully charged, it could run the bike for a short time, since a 36v fully charged is 42v, above the cutoff.
The 48v battery is likely toast. Hopefully you didn’t leave it unattended while charging it. If so, you’re very lucky.

 

[Mark Peddleman]

Your 36v battery voltage is below the controllers low voltage cutoff for a 48v battery, the controller will not operate. If it’s fully charged, it could run the bike for a short time, since a 36v fully charged is 42v, above the cutoff.
The 48v battery is likely toast. Hopefully you didn’t leave it unattended while charging it. If so, you’re very lucky.

Thanks for the input.
Update: bike with 48v battery installed has been sitting for a few days (no more charging) and occasionally the dashboard stays on
Longer, like 5-10 seconds and showing up to 18 MPH. Don’t know if this means anything.
Any thoughts?

 

[E-HP]

Any thoughts?

No body would touch it and online info was complicated and dangerous.

First though that came to mind

eBike Battery Recycling | powered by Call2Recycle, endorsed by PeopleForBikes

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www.hungryforbatteries.org

I don't know why you're still messing with it.

 

[d8veh]

I’m fairly new to ebikes. 48v battery was stored indoors for more than a year and this year I tried to charge it but nothing happened. Charger only blinked red.
I read that if voltage too low the circuit inside shuts down and has to be awakened. No body would touch it and online info was complicated and dangerous. Someone here tried a trickle charger for a long time and his battery woke up enough so the regular charger now worked with a solid red light. Tried the same thing but with a 36v charger. After several hours blinking red changed the solid red and finished charging till all test lights on the battery lit. Then I put the fully charged battery on the bike expecting all to be normal.
Not quite. Dashboard will not stay on more than a few seconds. Pressing the throttle those few seconds the hub motor would run but only a second or so till the dashboard shut off. I wondered how it would be if I put the 36v battery on the 48v bike. Now the dashboard came on like normal but charge level showed empty and throttle would not get motor to run.
I’m at a total loss as to what’s going on and how to fix it.
I’m hoping one of you guys with more experience and knowledge can help.
Thanks for any helpful information.

The only thing you can try is to open the battery and wire the charger directly to the cell-pack to bypass the BMS. There is some dannger in doing that for too long, so you should only do it for a few minutes until it'll take a charge through the charge port.