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  #1  
Old 27-10-2015
Nic8 Nic8 is offline
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Default Loosing power

I have a question, I am running 1/10th touring car 17.5 blinky and about 4 minutes into the race I loose power.
I can then be runing the rest of the race with full trottle but slower, so the question is, is it my esc, battery or motor.
The batteries have great punch to begin with and it happens to both, I did run a couple of meetings without balancing them, could it be they need a discharge and recharge to sort them out.

Cheers.
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  #2  
Old 27-10-2015
Big paul Big paul is offline
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what esc you running. It sounds like you may have a dodgy censure wire. Some esc will run in censureless, this feels like a drop in power. It may be the wire or the censure board on the motor. Or the esc or motor is thermalling (over heating).
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  #3  
Old 27-10-2015
Nic8 Nic8 is offline
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Cheers for the reply, I am using a hobbywing v3. I'll try a new sensor lead.
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Old 27-10-2015
jimjav jimjav is offline
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In my opinion it seems more a thermal or battery issue. Are you using a fan on the motor? And on the speedo? What ratio are you using? What lipos?
Best regards
Javier
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  #5  
Old 27-10-2015
Nic8 Nic8 is offline
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I am using a fan on both, the esc own fan and a 40mm on the motor. I am geared at 3.43 FDR.
They are different batteries, one a gens ace 5000mah 50c and a Turnigy ultimate 6000mah 90c.
The esc has the 4 capacitor option.
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  #6  
Old 27-10-2015
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beale beale is offline
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What is your motor temps? 3.4 is low for some motors what is the EBT that may be your issue, I use G force motors and like them, they do not like 40* + timing and less than 4fdr so I work with it in 17.5 but I like the consistent feel. Some like more and less
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Old 27-10-2015
Big paul Big paul is offline
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post back and let us know how you get on.
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  #8  
Old 28-10-2015
Nic8 Nic8 is offline
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For info I am running a hobbywing v3 esc with an LRP X20 17.5 motor with the EBT at 27.5.
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  #9  
Old 28-10-2015
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skyaflake skyaflake is offline
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LRP fade quite fast. Try to lower the heat or try another motor.
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  #10  
Old 28-10-2015
Big paul Big paul is offline
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Ok mate had a good old think about this. If it was over heating it would Just cut out. What battery cut off setting on the Hobbywing are you using. If set at 3.2v per cell and the voltage drops just for a nano second below this, it will send it in to censerless, try lowering your cut off to 3.0, or if you are coming of with plenty of volts left in the battery, tern it off for a run to see if that helps.
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  #11  
Old 28-10-2015
dpackster1980 dpackster1980 is offline
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Sounds like motor fade especially if the car comes off hot. Cheapest option is to replace the rotor and your motor will be as good as new. I can't imagine the motor will be pulling the cells down that much on a 17.5.
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  #12  
Old 28-10-2015
SlowOne SlowOne is offline
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+1 for the motor fade, LRP X20s do that. Very doubtful it is the sensor lead, if it were you would have had some stuttering by now on acceleration from stationery.

Try another motor, gear the LRP down or take the timing down to see how much the fade goes away. Fade is not always related to the final temps of the motor. It gets too hot during the run, the performance fades and then the temps drop a bit so when you finish the run it seems OK.

Sort the gearing and timing out on this motor so it doesn't fade, or change to a more robust motor that takes the timing and gearing without fade. HTH
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Old 29-10-2015
mattr mattr is offline
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Have you actually measured the temperatures?
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  #14  
Old 29-10-2015
jpmatrix jpmatrix is offline
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Default V3.0 esc

When i first installed my hobbywing v3.0 in my 4wd together with lrp x20 5.5t, after a few laps the esc would just go into a kind of limp mode and not produce the top speed that it should.

Was told by a fellow racer that you needed to disable the voltage cut-off as thev3.0 are known to produce the symptoms that you describe if you have it set to 3.2 or even 3.0volts.

Disabled it and has been fine ever since.
As long as you know your lipos are fully charged, a 5 minute heat will only take about 2000mah out of the battery so you are in no danger of damaging it.

I think the reason why the esc drops the top speed is that at some point in the race the battery's are under heavy load when applying full throttle and the voltage drops and that in turn kicks in the voltage cut off.


Try disabling the voltage cut off and the thermal cut off but check the motor temps and see if it solves the issue.
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  #15  
Old 30-10-2015
Nic8 Nic8 is offline
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Thanks all, I'll try each one of those ideas in turn and measure the motor temp. Cheers
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  #16  
Old 30-10-2015
mattr mattr is offline
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FWIW I've had the same issues as jpmatrix describes. Thermal cut out when the ESC/motor are still in the 40-50 degree temperature range (ESC was reporting the right temperature, but flashing the "overheat protection" LED.)

And a similar thing with low voltage protection, reporting about 3.9/4V, but flashing the LVC LED............

So I switched them both off, and spent some time working out how hot stuff was getting and how much juice I was taking out......
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