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Old 03-31-2008, 09:09 AM   #1
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Default Lipo voltage limit?

I know roar has been teching the voltage on lipos on bigger events. What is the highest legal limit?
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Old 03-31-2008, 09:19 AM   #2
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8.44v
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Old 03-31-2008, 09:21 AM   #3
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I know roar has been teching the voltage on lipos on bigger events. What is the highest legal limit?
The highest legal limit is 8.440 V.
Chargers are to charge a 2 cell lipo to 8.400V and ROAR is allowing a 40 mV tolerance.
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Old 03-31-2008, 09:23 AM   #4
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just blip the throttle a few times before going to tech and you will be just fine
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Old 03-31-2008, 10:03 AM   #5
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How can you get 8.44, when they are supposed to peak at 8.40?????
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Old 03-31-2008, 10:10 AM   #6
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Hey Ling, we tested a few Orions at Tamiya and found them all to hit 8.37v at most. What did you ever see with your testing? our TCS rules are right along the Reedy rules of peak of 8.44v.
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Old 03-31-2008, 10:13 AM   #7
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Thanks for the response.
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Old 03-31-2008, 10:22 AM   #8
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How can you get 8.44, when they are supposed to peak at 8.40?????
there's variances in the chargers, the was one charger at the carpet nats that would charge them over 8.44 even though the cutoff was 8.4
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Old 03-31-2008, 10:33 AM   #9
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Hey Ling, we tested a few Orions at Tamiya and found them all to hit 8.37v at most. What did you ever see with your testing? our TCS rules are right along the Reedy rules of peak of 8.44v.
Matt Hoard is right on the money. The voltage after charge is not battery dependant, but more dependant on your charger and how well it was calibrated.

Assuming your battery is correctly charged to 8.400V, it will come off the charger at around 8.38-8.39V. All chargers need to be calibrated so that when the charger reads 1V, it's actually 1V. If you open up most chargers, they have a little rotary Pot for voltage calibration. Sometimes the QC guy is having a bad day and your charger might be off a little.

Once I received a batch of chargers from Bantam, and a single charged cell ranged from 4.18X V to 4.23X V.
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Old 03-31-2008, 10:54 AM   #10
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there's variances in the chargers, the was one charger at the carpet nats that would charge them over 8.44 even though the cutoff was 8.4
There seems to be variances between chargers and from charge to charge with the same charger. At the Carpet Nats I got between 8.41 and 8.48 from the same charger and the same 4 batteries. I just discharged the battery at 1amp to get it to a legal level.

OUr Reedy engineer has told me that .04 volt is very low and is easily within the tolerance of the current chargers on the market. To increase accuracy, more expensive components will have to be used.

Chargers like the Pulsar have voltage calibration, so by manipulating this you can charge the battery to any voltage you want.

This is actually a timely post because I am currently testing LiPo batteries and have three voltmeters, a Turbo 35, a Pulsar, and a charger prototype that all read a different voltage for the same battery with a range greater than .04V.
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Old 03-31-2008, 12:04 PM   #11
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Thats good to know about the different variety of chargers. We were testing with a simple Orion Advantage Flight Charger. I opened it up, but did not see anything that would indicate a voltage adjustment. We will test more with a couple other chargers. I have another Orion Carbon Advantage, and I think we will test Fred's Orion as well.
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Old 04-01-2008, 04:24 PM   #12
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My Much More Silent Platinums both finish a battery at 8.36v. I opened one up and don't see anything that adjustable. I don't want to go the nimh charge mode route to finish. Anyone actually have a charger that's able to be calibrated??

A Pulsar 3 is? Is it inside or is it a function on the charger?
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Old 04-01-2008, 04:35 PM   #13
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My Much More Silent Platinums both finish a battery at 8.36v. I opened one up and don't see anything that adjustable. I don't want to go the nimh charge mode route to finish. Anyone actually have a charger that's able to be calibrated??

A Pulsar 3 is? Is it inside or is it a function on the charger?
You are talking a whole 40mv. You are not going to even feel the difference in the car. And do not use NIMH mode if you are smart.
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Old 04-01-2008, 04:42 PM   #14
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You are talking a whole 40mv. You are not going to even feel the difference in the car. And do not use NIMH mode if you are smart.
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Old 04-01-2008, 09:38 PM   #15
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Originally Posted by Rick Hohwart View Post
There seems to be variances between chargers and from charge to charge with the same charger. At the Carpet Nats I got between 8.41 and 8.48 from the same charger and the same 4 batteries. I just discharged the battery at 1amp to get it to a legal level.

OUr Reedy engineer has told me that .04 volt is very low and is easily within the tolerance of the current chargers on the market. To increase accuracy, more expensive components will have to be used.

Chargers like the Pulsar have voltage calibration, so by manipulating this you can charge the battery to any voltage you want.

This is actually a timely post because I am currently testing LiPo batteries and have three voltmeters, a Turbo 35, a Pulsar, and a charger prototype that all read a different voltage for the same battery with a range greater than .04V.





Did you find anything interesting with your testing?
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