Pygmy

Since I think there are probably a lot of people here on RCTech that know way more than I do about batteries and other electric magic stuff, I'd like to hear your opinion on this product :

CS Electronics 2S2P 7400mAh 150C :

http://www.cs-shop.de/Lipo+7-4V+7200...-+Hardcase.htm

Is the 150C spec real (or is it f.e. 60C continuous with 150C 'burst' ?)? And does it even make sense / useful to have 150C in a car ?

jk racing

iTrader: (20)

I am not one of the more magical knowledge guys, but to me that means 75C continuous and 150C burst.

Pygmy

aaaah, my bad, I somehow missed that !
Cheers !


..but 75C still seems rather high I think

tc5 man

Lol i wouldnt buy into them C ratings on lipos to much since there is no manf standard on them or testing . So really that lipo your talking about really is a 50c or a 60c with less burst. Just like Max Amps 150c

ta_man

iTrader: (168)

Actually, Danny (the battery guy at SMC) did some detailed testing to come up with a realistic criteria for C-ratings on LiPo batteries. According to his standards, the latest packs they were offering were 25C. That means they were actually tested at a 25C continuous discharge from full to empty. SMC offered those packs labeled at 25C. I have some and they are awesome packs. But with the 25C label, no one was buying them so the line was discontinued.

Now the same batteries (from the same factory, with the same specs, which BTW are 70C as rated by the manufacturer) are being sold with a label that shows the manufacturers made up rating instead of a rating based on rigorous testing.

They are selling well.

Hypocrisy in action.

tc5 man

This might sound weird but i bought a Max Amps 10,000mah 4s lipo from a guy i race with and it has a 25c rating and i run it on my truggy with a 2200kv and Mamba Monster Esc. And it has the punch of a 30c 4s lipo and doesnt even make the motor or Esc hot .

Now on a smaller scale a 25c is pretty low and will run hot with lack of punch.


And exactly about the Manf ratings on Lipos there just not true.

rcjunky1

iTrader: (10)

I look at it as a relative thing now as there is no real way of confirming the numbers. For example, the Team Great Hobbies 6600mah 99c continuous packs feel punchier for much longer then the 6500mah 50c packs, can the 99c pack actually but out 650amps continuous, I don't know, but they do perform better and are probably the best packs I've ran for the price.

protc3

iTrader: (13)

Some of the C ratings you see really are fictitious. Some of the advertised C ratings would literally melt the wires and connectors used on these packs if they were actually discharged at that rate. If you take the mAh of the battery, convert it to amps(7200 mAh = 7.2 Amps), Then multiply that by the C rating, that will tell you the claimed continuous discharge rate that the pack can handle. That would mean that the pack can take a continuous discharge of 540 amps. That is very doubtful. Just my opinion.

ta_man

iTrader: (168)

The point was that Danny came up with a well defined and reproducible way of rating the packs that anyone with readily available (though somewhat expensive) equipment could use and no one was interested in buying packs labeled according to a real standard because the numbers weren't inflated enough.

It is possible to measure a C-rating according to a reasonable standard but because all the current numbers are so inflated no one can produce measurements that back up the inflated numbers. So they have become "relative" and nothing more than marketing hype.

shagnat

iTrader: (55)

I say hogwash. Real or not, it's just not necessary to pay all those extra dollars for something like that.