Why is it stuttering?

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After running my savage flux hp for a little while without issue it begins to stutter:
The battery voltage was at 15.8v. Any input on what this is would be much appreciated...
 
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Wondering if it would be caused by old bad batteries. The ones I'm using came with the truck when I bought it second hand.
 

Jam Racing 1

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Could be old batteries, also could be slipper noise or gear mesh noise.... a bit of investigating will help figure out the issue....
 
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Thanks for the input! I have ordered a new set of batteries. Will post the result once I receive them
How does it behave when it reaches low voltage cutoff? Does it just stop or is there a low power period?
 

Jam Racing 1

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Thanks for the input! I have ordered a new set of batteries. Will post the result once I receive them
How does it behave when it reaches low voltage cutoff? Does it just stop or is there a low power period?
My LiPo powered vehicles usually just stop when they reach cutoff, but usually after a couple minutes it will go again under low power, so with that said I would go with known good batteries and while waiting for them I would take it down and verify the slipper and all gears in the trans and diffs are in good shape...
Making sure of all the components will ensure you are ready for some fun when your new batteries arrive....
Do you have a decent quality charger to top off your new batteries when you get them, They will arrive to you with a partial charge in them and will need to be charged fully before being run, it is also worth making sure of your cutoff point is properly setup and operating properly.... did you get the manual for the vehicle? if so it should be covered there as to how to do.....

https://www.hpiracing.com/instructions

Locate your model in the drop down menu and download it if you don't have it ,also the esc is covered in options so check your esc and download the correct manual for this also...
 
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Thanks for the input @Jam Racing 1 - I was actually going to check if there is some sort of reset to default on the ESC, will check if I can find the right manual - it was not included.

I have, I think, an ok charger. It's a Maxam Balance Pro 5000. I guess it might have other brand names other places in the world, as when I google it, I mostly get links to DK sites. Anyway you can select the charge current, and it seems to do and ok balancing job - cells are not in perfect balance, but within 0.05v

The included batteries are not in the best shape. They are 3s, but one of them had a collapsed cell, so I took it apart, removed the bad cell and put the 2 left back together. Unfortunately one of the tabs on one of the remaining good cells broke off during reasembley, so I'm now left with a 3s pack and a single cell "pack", thus 4s in total.

I have been out with the car maby 5 times, each time with fully charged battery.

Sometimes it starts and runes fine for maybe 5 minutes (standing backflips and wheelies at speed with no problem with the 3s + 1s config) but other times it stutters even with fully charged batteries, so it seems that the batteries are still able to deliver enough current, and the drivetrain seems fine.
When it stutters, and I try moving the car manually, there does not seem to be any problems with the drivetrain...

The 5 times I have gotten it to run, the cell voltage has been around 4 volts when it again starts stuttering. I'm wondering if it has anything to do with the voltage getting to low. I guess I'll not find out as the new batteries I have ordered are 3s.
 
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As far as I can google, the esc should be a Castle Creations Mamba Monster, but I hav not found a manual for that specific product. It seems it should be here: http://support.castlecreations.com/product-manuals-for-surface-escs
Under "Discontinued products" but there is no link to the Mamba Monster, only some other ESC's
I think I'll try disabling the low voltage cutoff and see if it can run below 16 volts, but would be easier with the correct manual :D
 

olds97_lss

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A weak solder joint or as you mentioned the motor joint could cause it to act sketchy. I had mine act similarly but it was when applying more throttle than a slow walk. Mine was because the one of the esc battery wires was nearly severed all the way through. I cut it off, resoldered the end on and it was good again. It just couldn't get enough current to operate properly.
 
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