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ROAR to change lipo voltage to 4.20 and 8.40

ROAR to change lipo voltage to 4.20 and 8.40

Old 12-22-2009, 05:32 AM
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Default ROAR to change lipo voltage to 4.20 and 8.40

According to the new 2010 ROAR rules the new lipo voltage is NOT to exceed 4.20 for 1S and 8.40 for 2S. There was an allowable +/- .02 per cell before!

http://www.roarracing.com/downloads/...ng_Minutes.pdf (page 4)

So how are all the racers with upgraded chargers and new chargers going to monitor and discharge there battery before going to tech for ROAR races from 4.22 and 8.44?

Discuss

Last edited by 1fastdude; 12-22-2009 at 06:32 AM.
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Old 12-22-2009, 05:37 AM
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Originally Posted by 1fastdude
So how are all the racers with upgraded chargers and new chargers going to monitor and discharge there battery before going to tech for ROAR races?
It's called a voltmeter.

Actually the rule before this was 4.20 volts per cell (which would be 8.40 for a 2s pack) with a tolerance of +/- .04 volts, to compensate for differences in voltmeters. It's racers who read that as max 8.44 volts. The changes in the wording merely reflect the original intent of the rule.

Charging a lipo past 4.2 volts per cell is considered damaging to the cell.
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Old 12-22-2009, 05:43 AM
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Seems like it's going to be a nightmare to tech. The Halloween Classic had a voltage meter that was reading really high for everyone. They switched it out and everyone was fine. If voltage meters all seem to read differently its not like I can just get a voltage meter of my own to check it.

It looks like for most voltmeters under $100 the accuracy is .5% which would mean a pack at 8.40v could read between 8.442V to 8.358V on the meter. I presume a charger uses a voltmeter as well. So if both had .5% accuracy and they both read in opposite directions the difference could be .084.

At the Classic they were allowing people to run their batteries down. How does ROAR handle that?
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Old 12-22-2009, 05:47 AM
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Wow...good thing I still have my GFX turbo 35. It has the older program that only charged to 4.20 and 8.40.

You would hope tech at events would allow a tolerance factor.
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Old 12-22-2009, 05:50 AM
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Originally Posted by jiml
Charging a lipo past 4.2 volts per cell is considered damaging to the cell.
Can you tell me where this information is and how .02 for 1S and .04 for 2S is going to damage our batteries?
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Old 12-22-2009, 05:54 AM
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Default 8.4V

good rule. we have that rule here too. tech has to agree on one voltmeter for the season (mainly cheap ones). rest of the clubs can than buy the same voltmeter (its only 10 bugs or so). so everybody has same measurements.
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Old 12-22-2009, 06:02 AM
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Originally Posted by 1fastdude
Can you tell me where this information is and how .02 for 1S and .04 for 2S is going to damage our batteries?
ROAR did some very extensive research into LiPo before allowing them in racing. It was the manufacturers who said the max should be 4.2v/cell.

How much of a difference is .04 volts going to make in how fast your car is?
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Old 12-22-2009, 06:04 AM
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Originally Posted by jiml
How much of a difference is .04 volts going to make in how fast your car is?
None, but I believe the question is about chargers that charge the extra .04. What happens?
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Old 12-22-2009, 06:06 AM
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What does it matter... if the voltmeter reads x or y.. just as long as only 1 is used to tech... or two that are calibrated the same. Racers can figure out how to be within the legal limits.

Last edited by TimPotter; 12-22-2009 at 06:28 AM.
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Old 12-22-2009, 06:30 AM
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I'm the guy doing all the 2010 tech for Roar..

That being said it's actually going to be easier than harder to tech, the Roar rules have always had the "standard" of 8.4V, with a tolerance of .04V. Roar made the decision to take away the tolerance of .04V.

For me in tech nothing is different, I just look at 8.40V and if your .01V off your DQ'ed, that simple.

If you were one of the hundreds of drivers that sent your charger away to "get updated to charge at 8.44V" you wasted your money. The "standard" is 8.4V and the company that sold you the charger knew that and should have only calibrated your charger to 8.4V, not 8.44V.

In all 3 of the Electric Nats in 2010 you're going to see me or the race director on the mic telling all of you that my voltmeter is the standard, yours is not. I'll have the voltmeter out the entire time I'm there for you to check your packs and there's no reason for you to be over. If my voltmeter is high or low, (which hasn't happened yet, it's a very good one) we will make the necessary changes and ALL of the racers will know about it ahead of time.

The whole is VERY simple; don't overcharge your LiPo's!
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Old 12-22-2009, 06:32 AM
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Originally Posted by Twin 1 Kevin
You would hope tech at events would allow a tolerance factor.
Roar DID allow a tolerance of .04V and racers decided to make it the standard, now there is a zero tolerance, just that simple
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Old 12-22-2009, 06:35 AM
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ROAR did not change the lipo voltage rule. The rule has always been 8.4v for a 2S pack. The allowable tolerance for charging differences was permitted for .04v which was never intended to be a standard. So, to say ROAR changed the rules is incorrect.

I can only imagine the reason for complaining about this.. is someone spent money to get a competitive advantage. Happens all the time things change, this is a small one, get over it.
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Old 12-22-2009, 06:38 AM
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Why in the world would ROAR have made the initial statement and allowance of .04 in the beginning AND change it NOW? If it was allowable in THE BEGINNING and racers are going BY THE RULES and getting their chargers upgraded TO THE RULES then why change it????? What has changed in the lipo battery that would make you change an existing rule? It certainly has not ruined ALL the batteries from 2009 has it because of the extra .04V? Must we all now dispose all of our 2009 lipos?
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Old 12-22-2009, 06:42 AM
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i think there should be a standard multimeter then, lets say a fluke meter this way there should be no difference in readings as was the case at the classic. these races are using 5 dollar multimeters that arent even close to being accurate.
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Old 12-22-2009, 06:43 AM
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When a big change in equipment is made, things like tolerances are made to help the racers adjust. The voltage caps were not in place for round cells ( maybe they were, but not teched).

When the tolerances are deemed to be unneccesary, then they are removed.
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