Big Rock Nero not responding to throttle inputs.

[ArrmaNero]

As the title says, after about 15min of runtime my Nero stops responding to throttle inputs, while the steering and difflock servos continue working. After I let it sit for about 10min it started to drive for about 5min before stopping with the throttle again. This 10min waiting-5min driving cycle continues until my 5200mah 3s lipos are empty. Anybody know what's happening? thanks in advance

 

[Exc3l]

As the title says, after about 15min of runtime my Nero stops responding to throttle inputs, while the steering and difflock servos continue working. After I let it sit for about 10min it started to drive for about 5min before stopping with the throttle again. This 10min waiting-5min driving cycle continues until my 5200mah 3s lipos are empty. Anybody know what's happening? thanks in advance

Is it overheating? It could also be battery sag.

 

[Bashtoohard]

Is it overheating? It could also be battery sag.

I agree. Overheating or pulling batteries down to quick hit lvc and then coming back up and working again, could also be a low C rating that would cause batteries to do the same thing

 

[ArrmaNero]

Is it overheating? It could also be battery sag.

Thanks for your reply, batteries were still cool after use, maybe the ESC or the engine haven't checked to be honest

I agree. Overheating or pulling batteries down to quick hit lvc and then coming back up and working again, could also be a low C rating that would cause batteries to do the same thing

Thanks for responding, my batteries have a 40C rating, is that too low? I just charged my batteries again and they still had around 2000mah capacity each, even though the truck didn't move anymore.

 

[Bashtoohard]

Thanks for your reply, batteries were still cool after use, maybe the ESC or the engine haven't checked to be honest

Thanks for responding, my batteries have a 40C rating, is that too low? I just charged my batteries again and they still had around 2000mah capacity each, even though the truck didn't move anymore.

Battery size depends on the amp rating of your esc. If you have a 100 amp esc your batteries should be sized at 125% of that, so you multiply c rating by battery amps. So a 5000mah battery would be 5 amps times a c rating of 40 = 200 amps. That would be a good size to use.
A bad cell in a battery wouldn't necessarily make batteries hot but still pull down really fast

 

[Monster-Crawler]

As the title says, after about 15min of runtime my Nero stops responding to throttle inputs, while the steering and difflock servos continue working. After I let it sit for about 10min it started to drive for about 5min before stopping with the throttle again. This 10min waiting-5min driving cycle continues until my 5200mah 3s lipos are empty. Anybody know what's happening? thanks in advance

It could be the motor, the esc, or both. You may wanna try a different set of batteries to see if that fixes the problem.

 

[ArrmaNero]

Battery size depends on the amp rating of your esc. If you have a 100 amp esc your batteries should be sized at 125% of that, so you multiply c rating by battery amps. So a 5000mah battery would be 5 amps times a c rating of 40 = 200 amps. That would be a good size to use.
A bad cell in a battery wouldn't necessarily make batteries hot but still pull down really fast

I use 5200mah 40c batteries, so that would give 5.2A x 40c = 208A. Its spec sheet says that the BLX200 can handle up to 150A continuous current capacity, is that the problem?

It could be the motor, the esc, or both. You may wanna try a different set of batteries to see if that fixes the problem.

Thank you for responding, I'll try that.

As the title says, after about 15min of runtime my Nero stops responding to throttle inputs, while the steering and difflock servos continue working. After I let it sit for about 10min it started to drive for about 5min before stopping with the throttle again. This 10min waiting-5min driving cycle continues until my 5200mah 3s lipos are empty. Anybody know what's happening? thanks in advance

I forgot to mention that I'm running the Nero with a dust cover to keep mud and sand out of the ecu fan. I'll try running it without the cover today to see if that's the reason something might be overheating.

 

[ArrmaNero]

Update: just ran without the dust cover, and the issue is a lot less prevalent, It only stops working for around 2 min every 5 mins of usage. Although this would point to overheating problems neither the batteries, esc nor the engine were hotter then they should be. After about 25mins of driving the truck stopped again and after waiting for around 10min I decided to turn it off and stop because it still didn't respond to throttle inputs. What do you guys think?

 

[L3phturn]

Get a cheap voltage alarm and run with it attached to the balance lead and set the alarm at 3.4v. It will beep when any cell drops to that voltage under load.

I think you have a bad cell and are hitting LVC when that bad cell drops under load and the total voltage drops enough to hit LVC. When you stop and wait the other cells charge the bad one back up and your total voltage comes back up and you can run again. Rinse and repeat.

When you hit LVC you need to stop running that battery. By continuing you are likely to be dropping one cell below 3v repeatedly and damaging it. Get a 5 pack of cheap alarms and a new battery.

 

[ArrmaNero]

Get a cheap voltage alarm and run with it attached to the balance lead and set the alarm at 3.4v. It will beep when any cell drops to that voltage under load.

I think you have a bad cell and are hitting LVC when that bad cell drops under load and the total voltage drops enough to hit LVC. When you stop and wait the other cells charge the bad one back up and your total voltage comes back up and you can run again. Rinse and repeat.

When you hit LVC you need to stop running that battery. By continuing you are likely to be dropping one cell below 3v repeatedly and damaging it. Get a 5 pack of cheap alarms and a new battery.

Thank you for replying, I will look into a cheap voltage alarm.

 

[Bashtoohard]

I use 5200mah 40c batteries, so that would give 5.2A x 40c = 208A. Its spec sheet says that the BLX200 can handle up to 150A continuous current capacity, is that the problem?

Thank you for responding, I'll try that.

I forgot to mention that I'm running the Nero with a dust cover to keep mud and sand out of the ecu fan. I'll try running it without the cover today to see if that's the reason something might be overheating.

I run 5500mah 60c as minimum on my kraton 6s. But 125% on a 150 amp esc it about 190 amps so your batteries are at the low end.

 

[ArrmaNero]

I run 5500mah 60c as minimum on my kraton 6s. But 125% on a 150 amp esc it about 190 amps so your batteries are at the low end.

Thanks for responding, I will look into getting new, more powerful batteries.
I believe I know what caused my problem, thank you all for responding and helping out!

 

[L3phturn]

Thanks for responding, I will look into getting new, more powerful batteries.
I believe I know what caused my problem, thank you all for responding and helping out!

Please come back and share once you confirm the issue, that way in the future others here with a similar problem can possibly find a solution.