Anybody had a bad battery in Ride1Up LMTD ?

[MikeL]

It seems that the battery in my new LMTD is defective.
After full charge I can ride on flat road in PAS 5 for about 15-20 min. After that the bike shuts down (looses power, display turns off).
After 10 more minutes it starts cutting off frequently even in PAS 3.
Voltage drops to 49v. And this condition is persistent. Even on the next day the bike shuts down immediately after I apply 50% throttle.
After another full charge battery shows about 52v (maybe 52.5) and the bike works for 15-30 min (depending on PAS level) and then voltage drops to 49 and the bike starts shutting down frequently.
Full charge takes less than 1 hour. Since charger provides only 2A, I can estimate that real capacity of my LMTD battery is about 2Ah, not 14Ah.
It does not look like over current or high temperature shut down since it happens even after long rest. Basically when voltage drops to 49v, any power consumption above 250W causes the bike to shut down. I have only one explanation so far - defective battery. Has anybody seen something similar ?

I also have Ride1Up 500 and it works well. No power issues.

I wrote to support, but they have not replied yet. It has been just 1 day after my message, but I keep checking my email every 10 min. It is a new bike and I want to ride it almost every day.
So far (before this battery problem) my experience with Ride1Up was good. The 500 works well and both bikes were shipped extremely fast (2-3 days).

 

[GenXrider]

That sounds like a controller issue. There have been some failures of those with LMTDs causing similar problems. I don't recall anyone reporting that the battery was bad. At 49V, the battery still is showing a good charge, and the bike should still work fine with that, even less. A full charge should be about 54.6 volts, but longevity of the battery will be better if you keep it in the 20% to 80% charged range.

 

[MikeL]

That sounds like a controller issue. There have been some failures of those with LMTDs causing similar problems. I don't recall anyone reporting that the battery was bad. At 49V, the battery still is showing a good charge, and the bike should still work fine with that, even less. A full charge should be about 54.6 volts, but longevity of the battery will be better if you keep it in the 20% to 80% charged range.

Thanks!

It is possible that something in the controller fails when battery is at 49v.

A few things that made me think the problem is rather with the battery (some cells are weak):

1) We rode LMTD and 500 with my brother. He was on 500. He is 30lbs heavier than me, but after the ride (about 5 miles with some hills), the battery in 500 was at 51v and in LMTD at 49v. Significant difference. Both were fully charged before the ride. Also LMTD voltage is dropping quickly. Sometimes I can see it dropping by 0.1v every few minutes even when the bike is stationary (motor is not running)! LMTD is supposed to drain the battery faster, but it seems too fast to me. I don't have a reference (another LMTD) to compare.

2) I am 99% sure LMTD battery was at 52.5-52.9 volt after full charge, not 54.6v. Below 53v. I did not measure 500 battery. I will check tonight.

3) When bike shuts down, the "Charge Level" LED on the battery cannot be activated by button press. Maybe BMS in the battery turns off the output.
If I disconnect the battery, LED starts working again. Maybe that actually indicates a controller problem. Maybe controller looks like short circuit to the battery in that failed state. Otherwise why would LED start working immediately after I disconnect the battery... I guess it senses abnormal load from controller/motor.
But this could also happen if some cells (not all) are bad and discharged and even normal controller/motor load causes BMS to cut off the power (because weak cell drops below min voltage).


I also have a 2-pin battery adapter/cable and I can test LMTD with the battery from 500. I would need to attach the battery with some straps and run the cable. That can be a good test, but I am not sure if Ride1Up would want me to do that.

 

[MikeL]

I verified that my LMTD battery cannot be charged above 52.5v. LED on the charger goes green and charging stops. The same charger can charge my 500 series battery to 54.5v. Now I am 100% convinced the problem is in LMTD battery.

 

[GenXrider]

Yes, that does sound more like a battery issue if it's only charging to 52.5 V when completely isolated from the bike with a known good charger. Hopefully support will assist you quickly to get back on the road.

I know some people have had batteries fail completely due to a blown fuse, easily fixed, but not like that.

 

[MikeL]

We quickly exchanged a few emails with Ride1Up support and they are sending a replacement battery.
So far the shipping from their warehouse to California was very fast. I expect the battery before weekend!

 

[MikeL]

Replacement battery arrived. No power issues. Climbed some really steep hills this evening just for testing.
Big thanks to Apollo (Ride1Up support)!
New battery color does not match my LMTD, but I am happy that it works.

 

[MikeL]

R1Up let me keep the old broken battery. I took it apart to see if I can fix it or at least reuse the case that has paint matching my LMTD.
As expected, the battery consists of 13 cell groups in series. Each group is a parallel connection of 4 LG 18650 cells. Wires look OK. BMS connector looks OK. It took some time to remove the silicon/resin compound they put inside the battery. I almost cut some wires while doing it. 11 cell groups out of 13 were fully charged and well balanced (4.15v each). Two remaining groups were almost fully discharged (about 3.6v each). Given typical very small balancing current capability of BMS, this battery would never recover by itself. With 50-100mA balancing current (per group), it would need 160-80 hours of charging to balance. And in this failed state battery can charge for 1 hour max. I would have to do a hundred of charge/discharge cycles.
I charged these 2 abnormal groups individually to 4.15v with RC charger and now testing. I was afraid these 2 groups are damaged by now and would not hold the charge as well as other groups, but so far the battery works OK. After 1 hour of heavy riding all cells discharged evenly to about 3.6v and seem to stay balanced. Need to do a few charge/discharge cycles to confirm.
What puzzles me is how the battery got to this state. If cells are not damaged, it is impossible to create such a huge disbalance between them by simply using the battery in ebike.
Maybe partially shorted BMS or wires could do that. i.e. maybe these 2 groups are always slowly discharging due to some small current leak...
I think most likely reason is that they assembled the battery this way (with completely unbalanced cells) and forgot to balance manually at the factory.

 

[Mike N.]

Good job figuring out the problem. I've noticed after riding for a length the controller will show remaining power like 48.2 volts lets say. Then I let the bike rest a bit and get back on and and at start up the battery will show 49.5 without a charge. I never noticed that effect on my first electric bike. I wonder if the cells are balancing themselves and it takes a bit of time.

 

[MikeL]

Good job figuring out the problem. I've noticed after riding for a length the controller will show remaining power like 48.2 volts lets say. Then I let the bike rest a bit and get back on and and at start up the battery will show 49.5 without a charge. I never noticed that effect on my first electric bike. I wonder if the cells are balancing themselves and it takes a bit of time.

Thanks. All batteries have this effect regardless of how well the individual cells are balanced. Even single cell battery.
Voltage will go back up after you stop using the battery. Using voltage for estimating remaining capacity is always inaccurate.
Sometimes you can give it a little throttle or PAS1 and read the voltage under that light load to estimate remaining capacity.