Display cut out and loss of drive

[iceclimber]

Cyrusher lanke S700 display
The behavior is - while under power, using the throttle under setting #1 or any # or peddling - the power cuts out and the display turns off. If I power cycle the battery, the display comes back on. I am able to select a power setting and or peddle and it may work for a while then cut out again. Sometimes it's immediately, other times it takes a while. If the power setting is set to zero, it doesn't happen. I've tried to isolate it to the throttle and jiggled wiring looking hunting for a short, with no luck.
Any ideas of where to look for a short or connection problem ?

 

[Chrstn]

It sounds like you’re dealing with an intermittent power cut that resets when you power cycle, which usually points to either a loose connection, a short, or an issue with the controller/display. Since it only happens under load (throttle or pedaling) and not at zero power, I’d check the following
Battery connections: Make sure all battery terminals and connectors are tight and corrosion free. Wiggle them while the system is on to see if it triggers a cutout.
Main wiring harness: Inspect all plugs and connectors from the battery to the controller and display. Look for partially seated connectors, broken wires, or damaged insulation.
Throttle and brake cutoffs: Even if you jiggled the throttle wiring, check the entire throttle harness and the brake levers’ cutoff switches. A sticky switch can cut power under load.
Controller connections: Open the controller casing (if safe to do so) and check for loose internal connections or cold solder joints, especially on high-current points.
Display wiring: Since the display goes off, the issue could be between the controller and display check the 3-5 pin display cable for continuity.
Heat or overload: Some controllers have thermal or overcurrent protection that cuts out under load. If the cutout happens more when it’s warm, this could be the culprit.
Start by wiggling each connection under power to see if you can reproduce the cutoutit usually narrows down the faulty connector or wire.

 

[RunForTheHills]

Could be voltage sag. The internal resistance of the battery increases with age, which causes the voltage to drop under load.

 

[iceclimber]

Funny I was (with no skills or knowledge) guessing something like that. So it's new battery or new bike ? Like is there any health treatment for that battery ?

 

[iceclimber]

It sounds like you’re dealing with an intermittent power cut that resets when you power cycle, which usually points to either a loose connection, a short, or an issue with the controller/display. Since it only happens under load (throttle or pedaling) and not at zero power, I’d check the following
Battery connections: Make sure all battery terminals and connectors are tight and corrosion free. Wiggle them while the system is on to see if it triggers a cutout.
Main wiring harness: Inspect all plugs and connectors from the battery to the controller and display. Look for partially seated connectors, broken wires, or damaged insulation.
Throttle and brake cutoffs: Even if you jiggled the throttle wiring, check the entire throttle harness and the brake levers’ cutoff switches. A sticky switch can cut power under load.
Controller connections: Open the controller casing (if safe to do so) and check for loose internal connections or cold solder joints, especially on high-current points.
Display wiring: Since the display goes off, the issue could be between the controller and display check the 3-5 pin display cable for continuity.
Heat or overload: Some controllers have thermal or overcurrent protection that cuts out under load. If the cutout happens more when it’s warm, this could be the culprit.
Start by wiggling each connection under power to see if you can reproduce the cutoutit usually narrows down the faulty connector or wire.

I did try some but not all of that. Thank you.

 

[RunForTheHills]

Funny I was (with no skills or knowledge) guessing something like that. So it's new battery or new bike ? Like is there any health treatment for that battery ?

If the cause is voltage sag, then yes, you need a new battery. Repairing the existing battery would essentially be replacing all the cells in it with new cells. There wouldn't be much cost savings, if any, over getting a new battery. The manufacturer, Cyrusher, seems to be having a sale on batteries on their website right now though.

 

[harryS]

I would diagnose this as a battery issue. One of the internal cell groups is probably low on voltage. When the battery sees a load, the voltage drops under the mininum and the battery turns itself off. It resets when the display powers down. Because we're only talking about a small difference in voltages internally, it cannot be seen from the outside with a meter

Someone with tech skills could open it up and prove the above, but bottom line, it is rarely an easy or economical fix. There's also the safety issues with battery fires.

 

[iceclimber]

great replies and thank you. Odds are dying battery. The Cyrusher was a good buy what like 5 years back and it's taken me places in the backcountry I had no business being in so very happy with the investment and the payback. So I will either buy a battery or a new bike. After the way I have treated this bike I am surprised it's in one piece lol.