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Old 05-11-2007, 01:34 AM   #1
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Default Li-po pack= slow car?! help!

I hit the carpet today with my T2 '007 and i put a freshly charged (first charge ever) li-po in it and the thing was slow, i mean i was going pretty good but it wasn't as fast as it should be. Is there something wrong with these packs, do they need a break-in?

At one point it really took off, there was plenty of power and then after about a lap it died off again? The ESC and Tx are programmed perfect. The motor is questionable but if it had all that power it must be an issue with the pack. I did not have time to test another Li-po I had.

These Li-po's are no names off ebay and are 7.4v 3500mah (2s1p)
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Old 05-11-2007, 02:02 AM   #2
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Quote:
Originally Posted by B18C Turbo
These Li-po's are no names off ebay
Ta-da! I think you have answered your own question.
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Old 05-11-2007, 02:05 AM   #3
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the first times i used lipos they where charged from the factory. they didnt go aswell as they do with a few charges in them.

i dont know if it will be the same for your batteries, but the ones i wwas using were maxamps
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Old 05-11-2007, 03:00 AM   #4
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what's the c rating of that lipo?
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Old 05-11-2007, 07:19 AM   #5
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Quote:
Originally Posted by B18C Turbo
These Li-po's are no names off ebay and are 7.4v 3500mah (2s1p)
You get what you pay for.
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Old 05-11-2007, 08:42 AM   #6
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uhhhh I garuntee that these cells are as good quality as the stuff Orion or Maxamps uses just without a label. Im not sure what the C rating is, i emailed the seller and if I remember right it was a 20C, im not sure positive but what does that mean?

I charge the packs at 3.5A on my LN-5014 Li-Po charger 7.4v and the pack charges to 8.4v-8.399v! After making about 6 laps I took the pack out and charged it again (took 66 minutes) and the voltage never changed. The pack never got hot during charging but got significantly warm during use.

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Old 05-11-2007, 09:08 AM   #7
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Originally Posted by B18C Turbo
uhhhh I garuntee that these cells are as good quality as the stuff Orion or Maxamps uses just without a label.
You should probably stick with NiMH batteries.
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Old 05-11-2007, 09:08 AM   #8
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Originally Posted by sosidge
Sorry, I didn't realise you were an expert in LiPo already. Since you know so much about them I am wondering why you bothered to post the thread.
ULTRA COMBO!
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Old 05-11-2007, 09:09 AM   #9
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Quote:
Originally Posted by B18C Turbo
uhhhh I garuntee that these cells are as good quality as the stuff Orion or Maxamps uses just without a label.
Sorry, I didn't realise you were an expert in LiPo already. Since you know so much about them I am wondering why you bothered to post the thread.
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Old 05-11-2007, 09:20 AM   #10
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Brother, what you are doing buying no name lipo's off ebay is simply dangerous! These cheepo chinese cells were probably made for some low amp draw device such as a clock! not really, but maybe a small plane or something not worthy to mess with. Actually I had the same problem with an electric R/C plane. It was a 11.1v 8C battery and it acted all slow and sluggish. Put a 11.1v 18C battery in and made a huge difference, RC cars are no different. The 20C you bought was probably on its best day if that, and not enough current is available to make your car fast. Do yourself a favor, and your track mates a favor, and get a orion 3200 lipo and be done with those ebay cells. You are running the risk of fire if you continue to run them.
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Old 05-11-2007, 09:24 AM   #11
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Well, give us more. Motor, ESC, gear ratio indoor, outdoor. You left out quite a few items. But the kicker, you bought BS packs. Dont skimp on the Li-pos, go with Maxamps, Orion/Peak or Kokam out the gate. Anything less than that, you are probably getting reject airplane packs that are safe, but weak. Case in point, your car is slow. Li-po packs generally shouldnt even get warm (unless you are overgeared or run below 6 volts). I have run my pack for a maximum 45 minutes and it barely got warm to the touch. Not trying to dis, but as stated by someone else, you get what you pay for.
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Old 05-11-2007, 09:32 AM   #12
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The part about "the motor is questionable" makes this whole thing unscientific.

I will say that in my experience, lipo's do not need cycling and perform perfectly on the first charge and do not improve after that. So don't expect the battery to get better, unless your charger setting was wrong.
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Old 05-11-2007, 09:32 AM   #13
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well now that has me worried because they did say they were to be used in heli's and airplanes! I figured they are the same size and numbers as an Orion carbon pack. I just cannot see the justification in why they charge triple for an Orion pack.
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Old 05-11-2007, 09:34 AM   #14
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Quote:
Originally Posted by bxpitbull
Well, give us more. Motor, ESC, gear ratio indoor, outdoor. You left out quite a few items. But the kicker, you bought BS packs. Dont skimp on the Li-pos, go with Maxamps, Orion/Peak or Kokam out the gate. Anything less than that, you are probably getting reject airplane packs that are safe, but weak. Case in point, your car is slow. Li-po packs generally shouldnt even get warm (unless you are overgeared or run below 6 volts). I have run my pack for a maximum 45 minutes and it barely got warm to the touch. Not trying to dis, but as stated by someone else, you get what you pay for.
Its a Kwik 27t motor good condition, 116spur and 27t pinion (64p), indoor carpet, GT7 esc.
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Old 05-11-2007, 09:47 AM   #15
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Quote:
Originally Posted by B18C Turbo
well now that has me worried because they did say they were to be used in heli's and airplanes! I figured they are the same size and numbers as an Orion carbon pack. I just cannot see the justification in why they charge triple for an Orion pack.
The cells are triple the quality, and over triple the safety. I would strongly suggest you take some time to educate yourself about LiPo before doing anything else with them. If that seems like too much trouble, you may want to stick with NiMH. There is no bargain with cheap LiPo, just danger and lackluster performance.

Stop what you're doing and read every page of this thread. Then, properly dispose of that cheap LiPo you bought and save your pennies for a quality pack.

http://www.rctech.net/forum/showthread.php?t=154155
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