Battery end of life

[Ute4492]

I don't think bad cells suddenly have a good day... So then your thinking that it may be the BMS sounds feasible.
I'd also test the charger as it could be as simple as that. Check and clean pins as well.
Sometimes troubleshooting intermittent electronics failures can have you thinking in all different directions.

Cleaned all connection points again. Took side case off unplugged and cleaned two connections.
Put the battery back in. Powered up and everything looks right. Went for a ride, all assist levels working.
I contacted Bulls and described my issues. They seem to think the battery may have one bad cell.
Checked my charger its putting out 42 volts. Attempted to get a voltage reading off the battery it came in at 19.4 volts.
Quite sure the bike wouldn't work if the voltage is that low.

 

[EMGX]

Cleaned all connection points again. Took side case off unplugged and cleaned two connections.
Put the battery back in. Powered up and everything looks right. Went for a ride, all assist levels working.
I contacted Bulls and described my issues. They seem to think the battery may have one bad cell.
Checked my charger its putting out 42 volts. Attempted to get a voltage reading off the battery it came in at 19.4 volts.
Quite sure the bike wouldn't work if the voltage is that low.

you might want to be careful and not blindly probe the contacts. the yamaha has a +, a - and a data port. Some people have bricked their $1,000 battery by probing across the + and the data port with a multimeter which shorted out the data port destroying the battery. I don't know if this is possible with the Brose battery but it is something to consider.

 

[Gionnirocket]

Cleaned all connection points again. Took side case off unplugged and cleaned two connections.
Put the battery back in. Powered up and everything looks right. Went for a ride, all assist levels working.
I contacted Bulls and described my issues. They seem to think the battery may have one bad cell.
Checked my charger its putting out 42 volts. Attempted to get a voltage reading off the battery it came in at 19.4 volts.
Quite sure the bike wouldn't work if the voltage is that low.

Sometimes testing an intelligent battery system can be a bit difficult. If the data pins aren't in communication with the partner, output voltage is prohibited. Typically a very low voltage or 0v is seen, but 19.4v seems odd... But this is proprietary so??
If there is a way to connect the battery to the bike and then access the power wires as they enter the motor may be your only choice. Authorized LBS may have a manufacturers testing procedure or tool that can do this easier or on a bench or even pull additional info from the data pins

 

[Ute4492]

Sometimes testing an intelligent battery system can be a bit difficult. If the data pins aren't in communication with the partner, output voltage is prohibited. Typically a very low voltage or 0v is seen, but 19.4v seems odd... But this is proprietary so??
If there is a way to connect the battery to the bike and then access the power wires as they enter the motor may be your only choice. Authorized LBS may have a manufacturers testing procedure or tool that can do this easier or on a bench or even pull additional info from the data pins

Thanks,
Going to the LBS tomorrow.
Found an interesting post here on EBR about my same issue.

While charging yesterday, the battery started flashing all 5 of the leds while charging and the charger would shut off.

Spent a couple of hours debugging this at the LBS today and Bulls is going to replace the battery. It looks like it might even be higher capacity as well (up to 750wh from 650wh)

LBS support was excellent as we debugged this issue with Bulls over the phone.

FWIW, Bulls has an EXCELLENT battery warranty of 4 years, are constantly improving them and making them backwards compatible for Brose.

Overall a hassle to troubleshoot but a good outcome.

 

[Mike TowpathTraveler]

That's great news to hear, Ute!

 

[MarkF]

A Bulls dealer should have been your first call to get things figured out if one was within range of where you live. I own a Raleigh ebike and I don't know where I'll go if I have an issue since they seem to be in-between jobs.