Drill one throttle cutting in and out at full throttle

[PoundingPonds]

I have a new drill one trail 19 electric dirt bike that’s having very upsetting problems. I fully charged my bike, take it for a ride and it ride’s perfect with no complaints for about 45 minutes. Then, when I get to about 48v the throttle will cut in and out while I hold it wide open. Doesn’t happen when holding the throttle 3/4 open nor does it do it when I put the bike up on a stand. Voltage is at 48v when it starts acting up. I should mention that when the problem happens the voltage goes from 48v and drops down to 35v and then back until I let off the throttle.
Fully charged it says it’s at 54v and the bike isn’t supposed to get into “limp” mode until 39-40v

 

[Chalo]

I have a new drill one trail 19 electric dirt bike that’s having very upsetting problems. I fully charged my bike, take it for a ride and it ride’s perfect with no complaints for about 45 minutes. Then, when I get to about 48v the throttle will cut in and out while I hold it wide open. Doesn’t happen when holding the throttle 3/4 open nor does it do it when I put the bike up on a stand. Voltage is at 48v when it starts acting up. I should mention that when the problem happens the voltage goes from 48v and drops down to 35v and then back until I let off the throttle.
Fully charged it says it’s at 54v and the bike isn’t supposed to get into “limp” mode until 39-40v

Sounds like a knackered battery to me. Check all the plugs and cables between cells and controller for any problems. Signs of heating, corrosion, lost terminals, cruddiness.

 

[PoundingPonds]

Sounds like a knackered battery to me. Check all the plugs and cables between cells and controller for any problems. Signs of heating, corrosion, lost terminals, cruddiness.

 

[PoundingPonds]

I emailed the owner of the company and he said he never seen it happen. Mentioned “uploading a new map” on the bms. I don’t have a HP computer so I haven’t had a chance to try that.

 

[Chalo]

Ah, I meant, "loose terminals". But lost ones would also constitute a problem.

 

[amberwolf]

Battery problem , most likely unbalanced (mismatched, defective or damaged) cells, with at least one group that has lower capacity / higher internal resistance, so when it reaches a certain point that group is emptier than the others and causes the entire pack to shutdown to prevent cell damage that could lead to a fire.

 

[Chalo]

Battery problem , most likely unbalanced (mismatched, defective or damaged) cells, with at least one group that has lower capacity / higher internal resistance, so when it reaches a certain point that group is emptier than the others and causes the entire pack to shutdown to prevent cell damage that could lead to a fire.

Knackered, as I speculated earlier.

Sad but inevitable, given the passage of time.

 

[lnanek]

Battery in the picture sure doesn't look enormous given they claim the motor is 15kW:

Drill One Evo | DEB

drillelectricbikes.com

I'd guess they just didn't put enough cells in parallel, so have bad voltage sag issues. At 48V, they'd need 300A to hit 15kW. The battery on my 750W bike is similar size and it can't even do 100A.