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Old 09-06-2009, 08:58 AM   #1
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Default ESC toasting LiPos?

I'm wondering if you experts could lend some advice to a relative newbie.

I have a Losi 8ightE that I bought in July and have run maybe 6 or 7 times. All stock components except for the Losi motor heat sink and Futaba servo.
Yesterday I was at a race at a new track (for me) and went out to do a practice run and my rig just stopped halfway through the first lap. When I checked the car there was no power to the ESC or radio. I figured I just had a bad battery (Losi 14.8V / 5000 mAh). When I plugged the battery into my charger I got a "Connection Break" alarm on my Venom Pro charger. Ok, that kind of confirmed my suspicions it was a bad battery. I put in my second Losi battery, set it on the track, and it went about 6 inches before stopping dead. I got the same message on my charger when I checked the second battery.
So now I have two expensive toasted batteries and what I assume is a bad ESC. Can a faulty ESC wreck a LiPo that way? Is this a common issue with Losi ESCs? In talking to the guys at the track I learned of at least three other guys that all had major problems with Losi ESCs. Most converted to one of the aftermarket brands, of which I saw one start on fire that same day.
So what is the deal here? Are the electronics for 1/8 racing just not capable yet? I can't afford too many $500.00+ race days.
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Old 09-06-2009, 09:07 AM   #2
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When entering into a new arena one has to expect a certain amout of problems. I have had my share of experiences which mirror yours. I had an ESC suck the life out of one of my 6S batteries causing it too puff up. I've had ESCs catch on fire and motors seize up. I think the brushless systems ARE getting better for the 1/8 scales but the manufacturers shouldn't do their R&D with funds from our pockets.

The short answer to your question is yes a faulty ESC can damage your LiPo by sucking the life out of it or going dead short and allowing the battery to transfer its capacity as quickly as possible. However, with the absence of physical damage, which you didn't mention (puffing) I tend to believe that the batteries connections may be bad after heating up and possibly desoldering themselves. You might want to peel back the covering on your LiPo a bit to check them out.
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Old 09-06-2009, 09:26 AM   #3
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There was no excessive heat from the ESC, motor, or battery. No puffing of the battery either.
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Old 09-06-2009, 09:31 AM   #4
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You need to look at your charger then. It could be defective. Start at the beginning.
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Old 09-06-2009, 10:08 PM   #5
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I too would check the charger first.
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Old 09-07-2009, 06:25 AM   #6
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I too would check the charger first.
what type of charger to you have?
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Old 09-07-2009, 07:03 AM   #7
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Do you have a volt meter that you can check the voltages of your batteries with?

An ESC could fry a battery, but that would require dumping a ton of energy somewhere and it doesn't sound like that is the case here. See if you can find a way to check your batteries with something other than your charger.
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Old 09-07-2009, 07:23 AM   #8
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Do you have a volt meter that you can check the voltages of your batteries with?

An ESC could fry a battery, but that would require dumping a ton of energy somewhere and it doesn't sound like that is the case here. See if you can find a way to check your batteries with something other than your charger.
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Old 09-07-2009, 12:40 PM   #9
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The charger I have is a Venom Pro. Bought it at the same time I bought the Losi 8E and have used it exclusively on the two Losi batteries that toasted.
Another guy at the track hooked one of the batteries up to his charger and was able to determine one of the cells was dead. I tried to revive it using super low voltage on the charger but it wouldn't go.
I just bought a second Venom Pro this week too. I thought they were supposed to be good chargers.
So how does a charger toast cells in a LiPo? It always seemed to function just fine and I always balance charged and watched each cells voltage and they were always within .01 to .02V of each other on the four cells when I fist started charging and then exactly the same when fully charged.
I'm still thinking its the ESC based on all I've read and heard about 1/8 ESCs.
Now I'm in a tight spot, do I buy another Lipo and plug it in to an ESC that may toast it? Do I buy another ESC and batteries? Can you test a charger somehow? I'm kind of stuck.
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