Power Drop Off

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Old 10-31-2009, 08:16 AM
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Default Power Drop Off

Hey All,

I run a SC10 on carpet with a Novak 17.5 and SMC 5200 24C 2S lipo. The past few weeks I have been noticing a power drop off after about 4 minutes of racing. This week it was very noticeable as I had a triple to measure against. My first thought is the lipo, but it is a very reputable brand and hasn't even felt warm yet. The battery is about 6 months old and sees about 3 heats of racing per week. What else could cause this power loss? Could my slipper clutch be slipping more as it warms up? Motor temps have only been 130-140F.
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Old 10-31-2009, 08:23 AM
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sounds like your lipo is getting old or your motor is getting soft chances are its the lipo though, just because it a brand name doesn't mean it will last forever.

and for kicks if you've ran the car 3 times each week for 6 month it would equal to 72 cycles per battery which is about when you'll see lipos start to degrade
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Old 10-31-2009, 09:36 AM
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Assume you've checked for any binding anywhere and that the slipper is in good shape? If its slipping to the point to explain the slowdown, suspect you'd hear it and see it in the condition of the slipper.

See if a friend will let you use a fresher lipo and see if that eliminates the slowdown. Easy enough to check that out.
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Old 10-31-2009, 09:50 AM
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Has your motor ever got TOO HOT, if so it will degrade the magnets forever. There really are alot of things it could be. See if you can borrow a pack from someone to see if the problem goes away.
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Old 10-31-2009, 10:19 AM
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Im also guessing motor. Have you double checked temps with someone elses gun & technique? In my experience a 17.5 cant take as much heat as a modified without going soft. If its been cooked it will lose power, and heat up quicker from then on.

If you had ran the lipo down to a very noticeable power loss several times I would expect you would see some puffing.
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Old 10-31-2009, 01:20 PM
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Thanks for the replies everyone. I think I will try to borrow a buddies lipo to compare. Deifinitely no binding present. I've been pretty careful with my motor temp and it does have thermal protection (Novak Havoc). If it is the lipo, I will be disappointed. It is my first but I think it is a good brand (SMC). It has never been discharged to the point of hitting the ESC cutoff. I don't remember voltage reading below 7.8V when recharging. I'll check the slipper too but I could not hear anything abnormal from the driver's stand.

What are some of the higher end lipo brands? I'm not much into the eBay specials when it comes to batteries.
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Old 10-31-2009, 01:44 PM
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I have been using lipos for about three years, and a drop off in voltage is not a typical sign of lipo failure. You can always send it to smc and they will check it for you. You bought from a good company who stands behind there products. If its defective they will more than likely refund you part of the price towards buying a new one or replace it if it defective.

I would suspect your slipper is worn out and slips more frequently as it warms up. Spend $2 and try the slipper first.
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Old 10-31-2009, 01:45 PM
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That thermal protection on your esc, is for the esc. Not the motor.....
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Old 10-31-2009, 02:00 PM
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Originally Posted by R-E-A-P-E-R- View Post
That thermal protection on your esc, is for the esc. Not the motor.....
Perhaps...but the Novak literature claims both ESC and motor thermal protection.

The highest I've measured, on the hottest point of the motor I had access to, was 170F. I am typically between 130-160F depending on track layout.
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Old 10-31-2009, 02:21 PM
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Originally Posted by nv529 View Post
sounds like your lipo is getting old or your motor is getting soft chances are its the lipo though, just because it a brand name doesn't mean it will last forever.

and for kicks if you've ran the car 3 times each week for 6 month it would equal to 72 cycles per battery which is about when you'll see lipos start to degrade
Wow i thought you could get more cycles than that?
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