Lmx64 battery status query

[Ukguy]

New to this forum and am looking for some help please. I own an LMX64 (3 yrs) and have a red flashing led on battery but the controller confirms high battery level (ie charged to 89%).

I had previously found the bike wouldn’t turn on and reached out to Steve at Stag motorcycles whom I bought the bike from. He kindly provided me with a new bms which I installed but he explained he was closing down the business so there appears to be no UK support.

I have run the battery down to 22% so that a recharge would possibly rebalance or synch. After a short time (about 3 miles), the battery status led is flashin red?

I have a friend who is more technical than me and it appears the battery is good. I have tried to use the bms App (XiaXiang) but this doesn’t pick up any battery via Bluetooth. Tried search via settings, same results. Am using iPhone 14.

Is there something simple I might have missed, I am not technical so any idiot proof answers much appreciated.

Many thanks

 

[E-HP]

I have a friend who is more technical than me and it appears the battery is good.

Can you describe how he determined the battery is good? Did he open it up and test the voltage of each of the 14 parallel cell groups? Try asking here E-S LMX 64 Bike Owners

 

[Ukguy]

Thanks for the response E-HP

I am getting normal range from the bike and my friend used electrical test kit which suggested the battery was fully charged. He didn’t test extensively as you asked but given the controller seems reliable as the range when riding is good - it seems just odd that the battery status led is in conflict?

I will try the link you offered. Many thanks

 

[E-HP]

Thanks for the response E-HP

I am getting normal range from the bike and my friend used electrical test kit which suggested the battery was fully charged. He didn’t test extensively as you asked but given the controller seems reliable as the range when riding is good - it seems just odd that the battery status led is in conflict?

I will try the link you offered. Many thanks

Ah, so the bike runs fine, and the only symptom is that the battery LED is flashing? Did you replace the BMS yourself, or did your friend? The connector between the BMS and battery pack is where you could test the 14 individual voltages of the parallel groups. That's where I'd start to make sure the pack is safe and in balance (I would try to eliminate or identify any issues that could leave to catastrophic failure first). If that checks out then diagnosing the issue may be less urgent.

 

[Ukguy]

Ah, so the bike runs fine, and the only symptom is that the battery LED is flashing? Did you replace the BMS yourself, or did your friend? The connector between the BMS and battery pack is where you could test the 14 individual voltages of the parallel groups. That's where I'd start to make sure the pack is safe and in balance (I would try to eliminate or identify any issues that could leave to catastrophic failure first). If that checks out then diagnosing the issue may be less urgent.

Yes the bike is good, plenty of range, just the battery led flashing.
BMS was replaced together (he works for Rolls Royce) and the process was plug n play with a hot glue gun used to hold temp sensors in place. Quite simply can’t see what we got wrong.
I also remember there was a plug in fly lead to the battery indicator, could that be a poor connection? However, it charges ok and the 3 green lights confirm battery charged, it is just that this status changes very quickly to a red flashing led. Manual says this is low battery as you would expect.
I thought the recharge would re-balance cells and the red flashing led would stop but same status persists. It doesn’t overly worry me as the bike provides good range, the battery is kept in a garage with radiator in winter and bike has only covered about 1000 miles so a fair weather user!
What does worry me a little is your term ‘leading to catastrophic failure’!
LMX support have simply suggested I order a new battery which is a lot of money when the bike runs so well with the new bms…
The lmx owners thread seem to have stopped a couple of years ago so thanks again for your help.

 

[E-HP]

Catastrophic failure isn't likely, but can't be ruled out when you have an undiagnosed battery issue. The cell group check is to make sure the BMS is doing it's job keeping the cells in balance. Cell voltages going too low or too high are symptoms to be concerned with. If the battery is charging and providing its normal range that's a good sign that things are balanced. If you experience the power cutting out or shorter ranges after a pack is fully charged, those are signs that some cell groups are unbalanced and with some not pulling their weight. Charging the pack fully, then waiting a day without riding it, and checking the resting voltage can also provide a good data point. If the voltage drops significantly, there could be some problems.

 

[99t4]

Won't be the first time that battery LED indicators incorrectly display battery charge level.

You should be able to easily test the battery voltage when fully charged (and 3 green LEDs), and then again when it starts the red LED flashing. That will give you a better idea of where the problem lies.

 

[Ukguy]

Catastrophic failure isn't likely, but can't be ruled out when you have an undiagnosed battery issue. The cell group check is to make sure the BMS is doing it's job keeping the cells in balance. Cell voltages going too low or too high are symptoms to be concerned with. If the battery is charging and providing its normal range that's a good sign that things are balanced. If you experience the power cutting out or shorter ranges after a pack is fully charged, those are signs that some cell groups are unbalanced and with some not pulling their weight. Charging the pack fully, then waiting a day without riding it, and checking the resting voltage can also provide a good data point. If the voltage drops significantly, there could be some problems.

Thank you again, excellent advice.
I am riding weekends only at the mo so I will bear in mind checking resting voltage..

 

[Ukguy]

Won't be the first time that battery LED indicators incorrectly display battery charge level.

You should be able to easily test the battery voltage when fully charged (and 3 green LEDs), and then again when it starts the red LED flashing. That will give you a better idea of where the problem lies.

Thank you, I can see that will give me some more clues.
In the meantime if bike is running well, I guess I can live with it but will apply this routine.
Much appreciate the help!