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Another LiPo Myth Exposed

Another LiPo Myth Exposed

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Old 07-07-2011, 02:55 PM
  #31  
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Originally Posted by GoatsnBros View Post
Will fix what?

All the melting wire and lipo cases that never happen under normal use?

If we wanted to be able to use the 60c power, we'd need to run larger bullets, 6-8ga wire, and a new type of connector.

After you do all that, your motor that was pulling <100A before, is still pulling the same amount of power. Your 60c lipo isnt running at 1/2 its advertized discharge rate, and you have more weight on your rig... But you can say you are running a 'superior' batter on a forum


Numbers mean things - to people who understand those numbers, and to those who dont.

People who dont understand, see the numbers and figure more=better, and since everyone is always in search of the best chassis, best esc, best servo, best batteries....they get what they think is best, without knowing what those numbers mean.


Same as the people that buy digital cameras based off the megapixel count...
The issue for some, primarily stock/spec racing classes with limited power and close racing, is not maximum amperage draw, but rather the ability to maintain a higher voltage under load.

Even very moderate loads. The higher discharge packs must have low internal resistance to achieve the high discharge capability, but this also helps maintain voltage at any load.

Very easy to demonstrate either on track or with test data, and supported by solid physics.

For many modified classes, and especially electric 8 scales, probably not much of an issue, generally plenty of power is available these days.
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Old 07-08-2011, 01:15 AM
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Originally Posted by JCarr View Post
I think that right there is the issue, a lot of tracks(in the U.S.) require the use of a roar legal pack. I don't think a lot of the cheap china packs a hard cased, much less roar legal. Personally I have felt a difference in every pack I have purchased, but I think it's because I am replacing an old pack with a new one so the punch is much better. I have never purchased two packs of a different brand at the same time to be be able to see any difference when new.
Being in the UK, things are a bit different here too.

I race at a club that will allow ANY hard cased 2c lipo. Afaik, to date we have not had any incidents involving lipo problems - with charging or during racing.

However, some clubs or championship series will use BRCA rules with an approved list of lipo's and motors to use.

(BRCA national events obviously will use the above mentioned lipo list ONLY).

Mine is 30c, not the most powerful but it is all I need, as we race in a hall that is only 10m x 15m so there is only so much power you can use.

Perception and reality are two elements in choosing a lipo pack in r/c that are wildly different.... Oh its 60c so it MUST be better is just a laugh IMO.

So yes, the enviroment you are racing in is just as much a factor as to which lipo you use to race with.
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Old 07-08-2011, 05:39 PM
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Originally Posted by Dave H View Post
There is a way to measure, use internal resistance. Just like we have for over 20 years.

And the various lipos do vary. (Please note I did not say anything about cost or name brand, just that the performance varies. Easy to name high cost-low performance name brand and vica versa)

Some chargers can do it, and there are small cell checking like devices that can measure IR. Note sadly the devices tend not to match up well, best to pick a measurement device and stick with it.
My Hyperion charger does measure internal resistance. I have used a wide variety of Lipos and can say there is definitely a difference from brand to brand. Sometimes its amazing to see a 100.00 pack with a higher internal resistance than a "cheaper made" 30.00 Chinese pack. I can tell you honestly for some odd reason MaxAmps packs were always one of the worst LOL.
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Old 07-08-2011, 08:25 PM
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Originally Posted by CarbonJoe View Post
Even funnier is that for these guys, it seems that the lower C rated batteries are sometimes faster (the theory being that the heat caused by the current draw is producing more voltage). This was with 28C rated packs vs. 60C rated packs.
I've heard that theory, but have never been able to support it with my own track experience (off road though, lower average draw) or reviewing various bench data. Seems if true the packs that start out at a lower voltage would gain and pass the higher volt ones during an appropriate discharge. Perhaps a case where testing is not representative for whatever reason?

You mentioned the 50C TPs not being better than the 40C for stock, I've heard the same. We've been running mod lately so I'm not as up on things, but I've heard the 65s are running good. What have you seen?
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Old 07-08-2011, 08:30 PM
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Originally Posted by Brushless420 View Post
My Hyperion charger does measure internal resistance. I have used a wide variety of Lipos and can say there is definitely a difference from brand to brand. Sometimes its amazing to see a 100.00 pack with a higher internal resistance than a "cheaper made" 30.00 Chinese pack. I can tell you honestly for some odd reason MaxAmps packs were always one of the worst LOL.
Sadly that example has caused a lot of confusion regarding this issue.
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Old 07-08-2011, 09:03 PM
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Originally Posted by TedMosby View Post
Exactly. I think even Dean's ultras are rated for 100amps or something.
I can't find the thread again, but I found one with the ratings of popular plugs and Deans was 50A cont, TRX and EC5's where at 100A and I wanna think the EC's where actually a bit higher. 150 maybe
Originally Posted by Wild Cherry View Post
I call it rip , yes, there's a obvious difference in performance between a good 20c & 60c pack ...
YEA, I'll agree. My neighbor has been running a 4000mAh 30c 2s Turnigy and recently bought a 4000mAh 20c 2s Zippy Flightmax and theres a very clear difference in the puch and top speed between the two
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Old 07-08-2011, 09:17 PM
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I know with my Protek batteries there was a very noticeable difference. I had a 5000 35c and 5000 50c, the 50c had a lot more punch and a higher speed. This was in both my SCT with Castle sidewinder system and my B4.1 with the RTR electronics. Now the Protek 65c and 50c batteries there is really no difference. Sucks they stopped making the 50c.
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Old 07-09-2011, 08:14 AM
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Most LiPo packs are overrated. Big Squid RC did a test. 30c LiPo + 30c discharge = workbench on fire!
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Old 07-09-2011, 09:24 AM
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i still use a 24c battery
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Old 07-09-2011, 05:55 PM
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Yea, I generally dont buy 40/50c packs. 5000mAh 20c-25c, 4000mAh 30c-40c. I dont think any higher than 120-150 amps cont. is needed.
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Old 07-09-2011, 09:52 PM
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Cool Love them EC5's!

Originally Posted by RCaddict0 View Post
I can't find the thread again, but I found one with the ratings of popular plugs and Deans was 50A cont, TRX and EC5's where at 100A and I wanna think the EC's where actually a bit higher. 150 maybe
EC5's, the only connectors I trust for my 6S powerhog.

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Old 07-09-2011, 11:08 PM
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[QUOTE=10 Gauge;9367615]EC5's, the only connectors I trust for my 6S powerhog.

Except.....there is a lot less current going through your connectors than the guys running 2s power.
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Old 07-10-2011, 08:47 AM
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[QUOTE=GoatsnBros;9367811]
Originally Posted by 10 Gauge View Post
EC5's, the only connectors I trust for my 6S powerhog.

Except.....there is a lot less current going through your connectors than the guys running 2s power.
I don't follow?
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Old 07-10-2011, 09:09 AM
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[QUOTE=10 Gauge;9368946]
Originally Posted by GoatsnBros View Post

I don't follow?
your amp draw on a 6S setup will be alot lower
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Old 07-10-2011, 09:33 AM
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[QUOTE=Matt Howard;9369005]
Originally Posted by 10 Gauge View Post

your amp draw on a 6S setup will be alot lower
How many amps are the 2S setups pulling?
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