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Old 05-23-2008, 11:46 AM   #1
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Default Lipo - odd lipo capacity usage situation

Ok had an odd (at least to me) situation with lipos last week running outdoor onroad. There were 3 of us running lipos with 10.5 motors.. I probably won't get these numbers 100% correct but it'll be close. Driver 1 was running a TA05 with an old Orion 4800 (at least 2 years old maybe 3). Driver 2 was running an MI3 with a Core 5000 (at least 6 months old). Driver 3 was running a TC5 with a Reedy 5000 (fairly new). After a 5 minute race we charged them back up and I found it interesting how much capacity was used. Here's the results of the Mah put back in the pack....

Orion - 3200+
Core - 1700
Reedy - 1600

I wasn't expecting them to be exactly the same but the Orion numbers seemed kinda wacky. All cars were pretty close in speed and lap times. Any thoughts on this? And yes they were all charged to near capacity before the race. Does the C rating have any effect on this? Is this something that happens with time to lipos... I mean would a newer 4800 do the same?
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Old 05-23-2008, 12:08 PM   #2
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I think the capacity required to recharge the Orion battery could be from many many factors. Battery Age, Drivetrain Effeciency (bad bearings, belt too tight), Motor mods (13mm Tuning Rotor on Novak, manually adjusting timing), ESC settings, and driving style.

I've run three different types of LiPo batteries, and the results are almost always the same, within 300mah of each other when recharging.
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Old 05-23-2008, 12:33 PM   #3
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I would check the car the used 3200 to find out why it used so much.

This last week on one of my cars that uses about 1100 Mah each race used 3500 Mah in the main. I knew something wasnt right so while I was checking the motor to see if it was pulling too many amps, binding in the drive train, etc. I found that a cooling fan I had blowing on the motor had locked up and was causing a direct short.

More than likely there is an issue that is causing the battery to drain like that.
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Old 05-23-2008, 02:01 PM   #4
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Yeah, if you don't find a bind or a short somewhere, your Orion pack may be somehow damaged. I've run a lot of different LiPos, and I've never noticed one taking significantly more/less charge than another.

Got a balancer? It might not hurt to see if a cell is out of whack.
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Old 05-24-2008, 02:56 AM   #5
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lipo normally decreases its capacity yearly by 10-15% whether you use it or not. and the high output one have more active chemistry characterizes, so expert it has more % decrease rate over the year.

about lipo is buy it and use it as hard as you can. time is what kills them.
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Old 05-24-2008, 05:28 AM   #6
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Quote:
Originally Posted by zenithrr View Post
lipo normally decreases its capacity yearly by 10-15% whether you use it or not. and the high output one have more active chemistry characterizes, so expert it has more % decrease rate over the year.

about lipo is buy it and use it as hard as you can. time is what kills them.
But this should just affect the "full" point, not the rate at which energy is pulled out of the cell.

Unless there was a large difference in the charge state at the start, or significantly more load on the pack, 2x is a big difference.

A couple of questions...

How were they geared?
Was one significantly faster than another?
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Old 05-28-2008, 11:40 AM   #7
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Sorry been on a little hiatus and missed a few posts. Well some sort of short... maybe. The Orion car was good ... meaning fast, free drivetrain, etc... He was geared a slight bit higher but not so much that I would expect to see as large a difference as we saw. We'll have to check the balance on the pack... its been checked but I don't think real recent. That's what seemed so strange cause this car is working awesome! Its just that it uses more juice... maybe that's why he is so fast. It would be easier to blame the car if it didn't work so darn good.
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Old 05-28-2008, 11:45 AM   #8
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probably cuz older battery there only supposed to last 300 cycles or so, well atleast thats what i hear. i would think though its older and u said it was geared different would make the difference.
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