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Old 02-21-2011, 04:02 PM   #1
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Default ESC for type of batteries?

Do you need to use a different ESC when running a NiMH battery to a Lipo battery? What I mean is that I have some old ESCs (Novak Racer and Duster) and I'm running a MiMH battery. If I were to start using a Lipo, do I need to change the ESC too?
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Old 02-21-2011, 05:18 PM   #2
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Do you need to use a different ESC when running a NiMH battery to a Lipo battery? What I mean is that I have some old ESCs (Novak Racer and Duster) and I'm running a MiMH battery. If I were to start using a Lipo, do I need to change the ESC too?
They will work just fine. The newer ESCs have a voltage cugt-off to prevent overdischarging lipos but you can either use an external cut-off like the Novak smart stop or time you run so you don't over discharge the pack.
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Old 02-21-2011, 05:48 PM   #3
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When you see a esc described as lipo ready or lipo capable, it usually just mean the esc has a builtin low voltage cutoff (lvc) to protect the lipo against overdischarge.

If you mind your run time well, you can run without, but you have to be careful. Another option is using a low voltage alarm (lva), but these just alert you that voltage is getting low. Its still up to you to pay attention, pull off and re-charge. A lvc is more direct - may either pulse the power to get your attention and or as voltage continues to fall without action on your part, stop the rc altogether.


You can easily damage a lipo by overdischarging it.
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Old 02-21-2011, 07:58 PM   #4
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Thanks for the good info. So if I'm using a lipo that's a 5000 mah with an older ESC, would it be safe to assume a 20 minute runtime without discharging the battery to a harmful stage?
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Old 02-21-2011, 08:25 PM   #5
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Originally Posted by CMUidiot View Post
Thanks for the good info. So if I'm using a lipo that's a 5000 mah with an older ESC, would it be safe to assume a 20 minute runtime without discharging the battery to a harmful stage?
No, never assume.

Depends on the motor you are using and the RC, and how and where you drive, etc. Too many variables. A heavy RC with a hot motor with lots of gearing, no way. Lighter RC, stock motor with moderate gearing, maybe.

Note in general a brushed setup will use more power for the same speed, it’s considerably less efficient than brushless.

Stock 27T motor, maybe start with 10 minutes top, hotter modified, perhaps 5 minutes or less, better safe than…. be sure to track the time. Then a couple ways to check: Check the at rest voltage, this you can do sorta on the fly. You don’t want it lower than 3.7V per cell at rest for best lipo life. Or recharge and note the amount put back in, stay below 80%, or 4000mAh in the case you mention. Then work your way up accordingly, but remain aware of variables that might increase power drain, and leave a cushion.

Even with a modern ESC with a cut off/LVC feature, stop as soon as it seems to drop off in power. Use the LVC as a back up only, it will help with cycle life.

Last edited by Dave H; 02-21-2011 at 08:39 PM.
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Old 02-22-2011, 06:16 PM   #6
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Thanks for the help. Dave, I see you're from RH in Michigan. Where do you race at, Larry's? Only reason I ask is that I'm originally from RH and my dad is just finding new places to run at.
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Old 02-22-2011, 07:52 PM   #7
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Used to race at Larry’s. But we like off road, nowadays most of our club racing is at Pheasant Runn in Holly, AMS in Grand Blanc, Dirt Burners in Livonia, and some others. We run the most excellent Factory Tracks Midwest multi track series. Plus we make whatever big races we can, the ROAR Nats and Regionals, MidWest Winter Championships, of course our local biggies like the fabulous Big Kahuna Shootout Memorial, etc. We includes my Team Driver, my Son.

You or your Dad are most welcome to contact me, always like to get people out to the tracks, fun times for all. Michigan is a great place for RC (I’m not a native btw), we have many national and worlds competitive level drivers, yet newcomers and returnees are always welcome too.

Here is a good site for Michigan track info:

http://www.rcracingextreme.com/forum/index.php

Cheers
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