Mamba Monster X, throttle cut and constant beeping.

[Relimar]

Happened after about 15 minutes of driving on two different 6S batteries. Car just stops, steering works, no throttle and constant beeping. Eventually cycling through the start-up cell detection and fired up again. Get home and check LiPo voltage, 3.7-3.8 all cells, so nowhere near the 3.2 cut-off. Best guess at this point is the batteries in my transmitter are low and it lost connection?

 

[Moirae]

have you checked temps?

 

[chris adams]

What beeps.

 

[Relimar]

have you checked temps?

I did not at the time, didn't have my gun with me. The tone chart as posted above shows a *_* short long shot, that indicates overtemp, it didn't sound like that, it was sounded just short short short... etc with no pause until it reset itself after a half a minute.

 

[Moirae]

I did not at the time, didn't have my gun with me. The tone chart as posted above shows a *_* short long shot, that indicates overtemp, it didn't sound like that, it was sounded just short short short... etc with no pause until it reset itself after a half a minute.

what lipo are you using?

 

[Relimar]

what lipo are you using?

Spektrum 6s, 22.2V 5000mAh 6S 100C Smart LiPo Battery: IC5

 

[Moirae]

Tbh it sounds like you're just hitting lvc, 15 mins of run time is not bad. 3.7 is very far from 3.2 though. Are you sure you have lvc set to 3.2?

 

[Relimar]

Tbh it sounds like you're just hitting lvc, 15 mins of run time is not bad. 3.7 is very far from 3.2 though. Are you sure you have lvc set to 3.2?

I never changed it and the manuals say 3.2 is factory default. Idk either, reached out to tech support and changed the batteries in my transmitter. I'll run it again and bring my temp gun see, what the deal is

 

[slick2500]

Tbh it sounds like you're just hitting lvc, 15 mins of run time is not bad. 3.7 is very far from 3.2 though. Are you sure you have lvc set to 3.2?

Yeah the Spektrum Smart batteries are notoriously known to not have the best cells in them, voltage sags under load then triggers lvc, you check the lipos and the voltage has settled back to resting state. I have my LVC in my ET48.3 set to 3.4 when I hit lvc and walked it back to my truck I was at 3.6v at rest.

I never changed it and the manuals say 3.2 is factory default. Idk either, reached out to tech support and changed the batteries in my transmitter. I'll run it again and bring my temp gun see, what the deal is

Do you have one of those beeper alarms?

 

[Relimar]

Yeah the Spektrum Smart batteries are notoriously known to not have the best cells in them, voltage sags under load then triggers lvc, you check the lipos and the voltage has settled back to resting state. I have my LVC in my ET48.3 set to 3.4 when I hit lvc and walked it back to my truck I was at 3.6v at rest.

Do you have one of those beeper alarms?

oh very interesting/terrible lol, I'll see if I can be more aware of what the transmitter is showing for voltage when it stutters

 

[slick2500]

oh very interesting/terrible lol, I'll see if I can be more aware of what the transmitter is showing for voltage when it stutters

Stutters? You never mentioned any stutters.

 

[Relimar]

Stutters? You never mentioned any stutters.

turn of phrase, it just stopped dead with no throttle response and left me with only steering

 

[Relimar]

The initial impression from the pleasant tech support person was that it sounded like an over-temp alarm. Going to run it tomorrow and check it.

Open to fan recommendations lol

 

[Relimar]

This look like a temperature cut-off to anyone else? Pink line in the graph

 

[Moirae]

Yea your esc definitely saving itself haha. You should check the blades on your esc fan and make sure the blades aren't broken. Those fans suck and they break extremely easy.

https://www.radiocontrolpower.com/product-page/40mm-rc-cooling-aluminum-fan

That fan will bolt right on to the mmx8s. You're better off plugging it up to the rx too. The mmx8s fan doesn't come on until it hits a certain temp. I think like 140f?? having the fan on from the start will definitely buy you more time before you overtemp. Also pretty sure the fan plug on the actual esc is limited in power compared to the rx so less volts going to the fan even when it is on.

 

[Relimar]

Yea your esc definitely saving itself haha. You should check the blades on your esc fan and make sure the blades aren't broken. Those fans suck and they break extremely easy.

https://www.radiocontrolpower.com/product-page/40mm-rc-cooling-aluminum-fan

That fan will bolt right on to the mmx8s. You're better off plugging it up to the rx too. The mmx8s fan doesn't come on until it hits a certain temp. I think like 140f?? having the fan on from the start will definitely buy you more time before you overtemp. Also pretty sure the fan plug on the actual esc is limited in power compared to the rx so less volts going to the fan even when it is on.

Solid help, thank you! That's what I thought I was looking at as well. I have 2 fans on the motor, but the esc is stock, definitely time to upgrade!

 

[slick2500]

Your motor temp is 587* F idk if those fans are helping out much. Might want to gear down.

 

[Relimar]

Your motor temp is 587* F idk if those fans are helping out much. Might want to gear down.

lol I saw that, also running at 3271 watts

 

[Relimar]

Okay, tested again today, it's not over temp. After about 15 minutes of running it, the throttle cuts out and the ESC does the 4 tone "Ring" that it does, it's not a beep code, it just rings over and over until eventually it catches and resets, ring, cell count and arms again. Sent a vid to tech support with the log, guess we'll see. A little nervous as this thing is a month old and I have a duplicate 1515/MMX combo waiting to go into the road car.

 

[slick2500]

Okay, tested again today, it's not over temp. After about 15 minutes of running it, the throttle cuts out and the ESC does the 4 tone "Ring" that it does, it's not a beep code, it just rings over and over until eventually it catches and resets, ring, cell count and arms again. Sent a vid to tech support with the log, guess we'll see. A little nervous as this thing is a month old and I have a duplicate 1515/MMX combo waiting to go into the road car.

It's LVC then. Your batteries are most likely sagging under load. 15 minutes is usually average especially if you are running it hard.