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Old 09-18-2010, 08:49 PM   #31
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Originally Posted by Still Bill View Post
Looks like you just nominated yourself to be BH's lipo coach...LOL

And I do like your reference to OD in your signature.
I do what I can.

Definitely. OD is the man.
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Old 09-18-2010, 09:02 PM   #32
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More of reader, NOT trying to over charge. That's why I ask the question maybe you should read it.
You should read your own first post. You apparently charged to 8.5V.

I gave you the benefit of the doubt initially; but, got concerned when I noted how few posts you had on RCTech. That's when I went into 'safe mode' with my last post.

FYI...I see a lot of puffed lipo packs in the trash at my local race track...Hence my concern for your safety.

Go with stiltskin. He is certainly respected by me for his posts (and knowledge) on this board.

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Old 09-19-2010, 05:43 AM   #33
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Originally Posted by Still Bill View Post
You should read your own first post. You apparently charged to 8.5V.

I gave you the benefit of the doubt initially; but, got concerned when I noted how few posts you had on RCTech. That's when I went into 'safe mode' with my last post.

FYI...I see a lot of puffed lipo packs in the trash at my local race track...Hence my concern for your safety.

Go with stiltskin. He is certainly respected by me for his posts (and knowledge) on this board.

Bill
If you look at what I said was my LCD displayed 8.4V, when the Race Tech used a VOM it read 8.5V. My manual does not explain Plus Charge mode which was on when I set-up my Charger.

Last edited by Bubblehead; 09-19-2010 at 05:54 AM.
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Old 09-19-2010, 07:03 AM   #34
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Having been a past "victim" of the overcharging craze with NIMH packs, I say that ROAR had very good reason for taking a safe stance with lipos when they made their original call on maximum allowable voltages for events.

Besides OD (and at the really big events), I rarely see anyone charging their packs in an approved lipo sack. All the more reason for ROAR to be more so on the safe side.

And Bubblehead only having fifty-some posts on RCTech also gives me reason for additional concern. He may well be a newbie and likely should not be pushing lipo charging limits with such limited experience. BH should otherwise be working on his driving skills to obtain optimum results.

Bill
Is it a (safe stance) to approve of something so inherently dangerous? If people have their own VOM at track to check their voltage before tech to me something is wrong. Is my charger the only one over charging?
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Old 09-19-2010, 07:16 AM   #35
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I think some variation in voltage is common with chargers, probably cause it's time consuming to calibrate them off the production line, but most I have seen have a calibration function, even the cheap ones.

Mine came up low when I checked it, I found the calibration function and was going to adjust it, then realized I had no idea how accurate my multi meter was, so it could have been a pointless exercise.

In the end I have yet to see high voltage make all that much a difference, and given my own lap times (I always set my fastest lap times at the end of a race) I'm not sure I would gain anything, so I figure the fact my own charger read low was likely a good thing for safety considering it was a cheap ass charger.

If it's reading high though, I'd be a lot more worried, high can't be good.
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Old 09-19-2010, 07:23 AM   #36
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Is it a (safe stance) to approve of something so inherently dangerous? If people have their own VOM at track to check their voltage before tech to me something is wrong. Is my charger the only one over charging?
LiPos aren't inherently dangerous. If they were, the major auto manufacturers wouldn't be using them in electric cars. The problems arise when racers abuse them, either by over charging or over discharging. Like that extra 0.04 volts is going to vault them from the Sportsman D main to the Mod A main.

As with all manufactured products, there are tolerances on everything. Better to err on the side of safety. Why risk a DQ or worse for 0.04 volts?
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Old 09-19-2010, 08:50 AM   #37
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Joe hit the nail on the head.

If your charger is overcharging the pack then the voltage will read high at the tech table.

I ran in the 2010 ROAR 1/10 off-road Nats and I tech both packs at 8.39-8.40V each time. I only used a 1C charge rate using an icharge charger. There were several people that were overvoltage but once they started using a 1C charge their packs were at or below 8.4V. My pitmate had the other problem, his charger never fully charged his packs so his voltage was 8.2-8.3V., He still made the B-Main and if he hadn't made so many tiny mistakes he would have been in the A-Main. The lower voltage didn't hold him back.

(The Passport Charger he used needs to have the amps maxed out to reach full voltage. That "fix" from Horizon's tech is pretty shabby if you ask me.)
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Old 09-19-2010, 09:39 AM   #38
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If you overcharge lipo batteries too much they can catch on fire and burn down your whole village. The rule is for safety. ROAR's rule is 4.20/8.40v, most others still use 4.22/8.44v. Most agree that either of those limits are well within safety concerns. Is a disqualification neccessary for .1v? Most people think not
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Only in ROARs eyes..
.1 over voltage is illegal everywhere not just in ROAR.


Maybe the root of the problem is the fact that classes are being raced were .1V makes a difference (perceived or real). I charge my mod packs to 8.35.
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Old 09-19-2010, 09:53 AM   #39
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Originally Posted by Still Bill View Post
Having been a past "victim" of the overcharging craze with NIMH packs, I say that ROAR had very good reason for taking a safe stance with lipos when they made their original call on maximum allowable voltages for events.

Besides OD (and at the really big events), I rarely see anyone charging their packs in an approved lipo sack. All the more reason for ROAR to be more so on the safe side.

And Bubblehead only having fifty-some posts on RCTech also gives me reason for additional concern. He may well be a newbie and likely should not be pushing lipo charging limits with such limited experience. BH should otherwise be working on his driving skills to obtain optimum results.

Bill
LMAO.. So post count on this site is in direct relationship with your R/C experience? Funny stuff!!
I have never had any of my chargers that would even allow you to overcharge to an unsafe level, not even the cheap ones.. I see more fires due to incorrectly soldered wires on the esc or people reversing the wires on the battery, nothing a post count or 4.2v per cell can help with..
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Old 09-19-2010, 10:09 AM   #40
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ha ha yeah I was going to say the same thing... just because we are newbies on rc tech doesnt mean we dont know anything about rc.. I have been racing for over 12 years so go figure.....
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Old 09-19-2010, 10:17 AM   #41
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some ppl are talkin about .1 of a volt over and some are talkin about .01 of a volt over... I guess you guys need to read the posts properly and get some stories right.
But I only have few posts on rc tech but I can read...
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Old 09-19-2010, 10:20 AM   #42
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I would do what Rick says, just put a lower cutoff......the extra .01 volts is not going to make you win or lose. Less than 1% of all the drivers in the world can take advantage of those extra hundredths of a volt....with Rick being one of them, he doesn't even risk it....

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Old 09-19-2010, 10:22 AM   #43
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LiPos aren't inherently dangerous. If they were, the major auto manufacturers wouldn't be using them in electric cars.
Well yes and no, really only some mobile devices use the same chemistry we use in RC from what I can see (people keep saying 'lipo' is used in auto cars, but I have yet to find one example of that, I always find they are using a slightly different and more stable chemistry) , and when it is used in other devices it's kept in a remarkably small voltage range compared to what we use.

Think like maxing out at well below what we normally charge to, and never let fall below or discharge at a rate we do, the inherent difference is we push the most volatile version to it's limits, even when we go easy it's likely well above what anything else would ask of them, which is where the risks come in.

I gather this is probably why we should never push the limits of a charge, we are all ready pushing those limits.

But then the same was often true of past batteries, perfectly safe in 99% of things, yet RC guys can and will short, overload or melt anything we use just by pushing the limits.

To compare the what we use with other devices is a far removed thing, take one perfectly safe battery, push that battery to 150% of what anyone else does with it, and still call it 'safe'?.
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Old 09-19-2010, 10:37 AM   #44
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I am actually in the market for a really good charger. Does anbody have any suggestions? I've been told that all lipo chargers are pretty much the same as far as the quality of the charge, is this true? Compared to the nimh days.
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Old 09-19-2010, 01:38 PM   #45
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Just to hopefully settle this. There is an update for the original posters charger in question (610C) that is meant to address car racing voltage. Lets hear it for firmware upgradable electronics!
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