Not working on high mode

[Paulius]

Hi, cannot find a problem on my ebike. Bike works only on low power mode (assistance mode), wen I turn to high mode after few seconds bike turns of. Tis happens only when I am riding on the bike, but if I put high mode on bike stand it works on all modes and do not turns off. Sometimes on display are flasing low and high mode lights. Short video how it looks: https://www.kapwing.com/videos/63f093a598580500ed06a2fb
What it can mean? Where to search to problem?

 

[sjpt]

It can happen if the battery isn't up to providing the current the full power needs. That can be an old battery that is losing power, or (especially with high power direct drive motors) just a battery that is not up to the job.

You don't say what kind of bike, motor, controller, battery; more details would help.

 

[matthewslack]

Hi, cannot find a problem on my ebike. Bike works only on low power mode (assistance mode), wen I turn to high mode after few seconds bike turns of. Tis happens only when I am riding on the bike, but if I put high mode on bike stand it works on all modes and do not turns off. Sometimes on display are flasing low and high mode lights. Short video how it looks: https://www.kapwing.com/videos/63f093a598580500ed06a2fb
What it can mean? Where to search to problem?

More detail would be helpful, for example is it hub motor or mid drive, is this a new problem, spec of motor and battery, age of battery, and so on.

Based on the info given, your battery may be the problem. When you ride in high assistance you ask for high power, which pulls the voltage too low and the BMS turns off. In high mode on the stand, it does not need so much power, and so works.

 

[cyclebuddy]

I agree with the comments already made above about your battery likely being old/worn/no longer being able to produce the current needed.

Sometimes on display are flasing low and high mode lights. Short video how it looks: https://www.kapwing.com/videos/63f093a598580500ed06a2fb

As for the low/high LED's flashing (790), IMO it's a different problem and sounds similar to this post here where it's a brake sensor fault.

 

[Paulius]

It is from hub motor. Just bought this bike with this problem. Battery voltage looks good after charging it shows about 52V (battery the same as there: https://kwsseuren.nl/phylion-joycube-36v-phylion-joycube-36v.html).

As for the low/high LED's flashing (790), IMO it's a different problem and sounds similar to this post here where it's a brake sensor fault.

Already tried to disconnect brake sensor from controller, but it not helped.

 

[matthewslack]

It is from hub motor. Just bought this bike with this problem. Battery voltage looks good after charging it shows about 52V (battery the same as there: https://kwsseuren.nl/phylion-joycube-36v-phylion-joycube-36v.html).



Already tried to disconnect brake sensor from controller, but it not helped.

Is it a 250W small geared hub motor, or a higher power one? If unsure, add a picture.

 

[Nealh]

With that display the 790 one can fault find using the flash code.

Find the manual for your 790 and you should ge tthe anwser.
The pendleton bike uses a similar 790 display and the L/H flash code = Brake sensor error.

 

[Nealh]

Other wise if the bike cuts out and one doesn't see the L/H flashing then the issue is likely a current delivery issue or general battery fault.

Reading from #5 it sounds to me like you are using a knackerd battery that simply is that knackered or badly out of balance.
Your battery being use is 48v one that shoul dfully charge to 54.6v, 52v fully charged means it is either knackered, a dead or duff cell group or terribly out of balance.

A battery that cuts out when high power is asked of it means it is well past it's best and indicates severe /bad voltage sag that hits LVC , hence the cutting out. In lowe power use they will still work to a degree until lvc also comes into play when the terminal battery voltage lowers.

 

[Nealh]

The conclusion form my point of view is a knackered battery.

 

[Zlatan]

Hi, cannot find a problem on my ebike. Bike works only on low power mode (assistance mode), wen I turn to high mode after few seconds bike turns of. Tis happens only when I am riding on the bike, but if I put high mode on bike stand it works on all modes and do not turns off. Sometimes on display are flasing low and high mode lights. Short video how it looks: https://www.kapwing.com/videos/63f093a598580500ed06a2fb
What it can mean? Where to search to problem?

Just a thought... Try your speed sensor connections.. (if it has any?)
Had a similar issue on my ebike. Bike would work perfectly for 15 seconds or so, then give nothing. Unplugged speed sensor (at motor, was a pain to get to) WD 40 on terminals, good clean, adjusted magnet alignment and worked fine thereafter.???

 

[Bikes4two]

As has been said, it looks as though when the battery is under heavy load (ie riding in the hi assist mode) the battery can't cope.

If this is the case and you were able to monitor the voltage at the same time, then you'd see the large volt drop.

Whilst it might be a faff to wire a volt meter somewhere so that the reading is visible when riding, at least you'll have confidence about the diagnosis before spending oodles of dosh.

 

[Bikes4two]

Just a thought... Try your speed sensor connections.. (if it has any?)

If the bike is working OK on low assist then one would assume the speed sensor is working, no?

 

[Zlatan]

If the bike is working OK on low assist then one would assume the speed sensor is working, no?

I, d guess so, but worth checking all same. Costs nothing and only 10 mins or so.