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Old 03-10-2013, 12:48 PM   #91
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Originally Posted by Shawn68z View Post
I agree with you that your method will give you superior results, at the cost of reducing the number of cycles the battery will last for. You can also charge the battery at 1C, and warm it up for the same results.

Shawn

I have a Venom 5600 60C 2 cell that's over two years old and still has a 12.0 IR.

Charging at 1C the IR was much higher and the voltage drop sooner same pack.

The internal resistance was checked using the VR-1 Charger.
The VR-1 checks the IR throughout the discharge cycle.
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Old 03-23-2013, 11:18 PM   #92
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where can we get these smc lipos? They seem to be back ordered for awhile now.
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Old 03-24-2013, 01:56 AM   #93
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Still running the yellow and red intellect 30c batteries every fortnight from boosted stock to now modified, must be 4 years old and only recently a couple have puffed. I have found little performance difference to the newer packs I have.
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Old 03-24-2013, 09:57 PM   #94
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Originally Posted by Pit-racer View Post
where can we get these smc lipos? They seem to be back ordered for awhile now.
Keep checking with SMC - should be first week in April.
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Old 03-25-2013, 05:53 AM   #95
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There is already a way to test them if you feel the need. Get a Castle ICE airplane ESC, put a motor and prop combo on the bench and test away.
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Old 03-25-2013, 01:10 PM   #96
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Personally, I don't care what each cell IR and C rating is. It would be much more useful to know what the assembled battery can do. A standardized test with no connector and a nominal lead length (say 3 inches).

How many watts can I get out of the battery...
1. Safely (recommended max discharge rate, any higher and you are shortening the battery's lifespan)
2. Before predictable failure (Discharge rate at which permanent battery PACK damage occurs such as puffing, solder joint failures, melting wire, etc...)

There are people who take care of batteries (racers) and there are people who abuse batteries (bashers). Bashers far outnumber racers and they are the ones who need to know that if they try to run "this" 3s 3000mAh pack (meant for an electric plane) in their overgeared Savage Flux that it is probably going to end spectacularly at some point. The racers only need a voltage over time (at a set load) or watts over time graph to decide what battery will have better punch. And like has been stated a few times, a load and a data logging ESC can give you that.

I for one would love to be able to buy a one-box battery dyno that can tell me how an assembled battery pack performs. This way you can also accurately observe how your batteries degrade over time from use/abuse.



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Old 03-25-2013, 04:34 PM   #97
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Quote:
Originally Posted by Radi0Flyer View Post
Personally, I don't care what each cell IR and C rating is. It would be much more useful to know what the assembled battery can do. A standardized test with no connector and a nominal lead length (say 3 inches).

How many watts can I get out of the battery...
1. Safely (recommended max discharge rate, any higher and you are shortening the battery's lifespan)
2. Before predictable failure (Discharge rate at which permanent battery PACK damage occurs such as puffing, solder joint failures, melting wire, etc...)

There are people who take care of batteries (racers) and there are people who abuse batteries (bashers). Bashers far outnumber racers and they are the ones who need to know that if they try to run "this" 3s 3000mAh pack (meant for an electric plane) in their overgeared Savage Flux that it is probably going to end spectacularly at some point. The racers only need a voltage over time (at a set load) or watts over time graph to decide what battery will have better punch. And like has been stated a few times, a load and a data logging ESC can give you that.

I for one would love to be able to buy a one-box battery dyno that can tell me how an assembled battery pack performs. This way you can also accurately observe how your batteries degrade over time from use/abuse.



Sean
Its called IR (internal resistance).

The lower the IR number the faster the battery will release its power.

There are a few chargers out there that will display the IR of each lipo or other battery pack.

If the lipo sits for a short time it will have a higher IR number.

It make a HUGE difference running a lower IR over running a higher IR in competition.

To lower IR one way is to warm up the cell as it charges at a higher rate (3C). The Tier ONE or TWO lipo cells. NOT THE CHEAP CELLS!!

First discharge the lipo pack down to 3.0 volts/cell.
Then charge at 3C.


I have a two year old 2 cell Venom lipo pack still at 12.0 (6 mil ohm per cell)
Turn the track record with it.

The method doesn't loose battery life.
It only improves it.
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