I see my smc lipos say that you can charge them at 2c and the new hyperion series of lipos say 5c same with the neu energy.

How many amps is a C?

All depends on the battery milliamps. 1c on a 5000mah pack is 5.0 amps, 1C on a 4500mah pack is 4.5 amps.

Divide the mah by 1000 and you get 1C. To charge at 2C just double that number.

ok thanks,

so to charge a 5000mah at 2c would be charging at 10amps?

so those hyperions can charge to 25amps on a 5000mah? craziness

not 25c...5000mah @ 5C would be 25 amps but you'll need a BIG power supply and I don't know if you'll find a charger that charges that high.

yes a 5000mah pack @ 2C is 10 amps. Hyperions say you can charge them at up to 5C but your biggest gain in lowering your charge time is when you go from 1C to 2C after that the amount of time you save becomes less and less noticable. This is info I've heard from a knowledgable source not my personal experience.

I see you edited your post, now it is correct.

hyperion has a charger that does 20amps
http://www.allerc.com/product_info.p...oducts_id=4305

but thanks, i understand what you are saying.
would charging at such a high rate, even 10 amps on a 5000mah hurt the battery in any way? I know it would charge faster but would it decrease the life?

Just to keep in mind, charging above 5 amps will decrease the life of the lipo. If it "says" that you can get "100" charges for the life of the battery, charging at 10 amp will give you "50" charges for the life of the battery.

You shorten the life of it.

I personally don't know I don't have a need to charge over 1C. I realize "100 and 50" are just reference numbers but it's not going to cut it's life in half. These charge rates for these types of packs haven't been out long enough for anybody to REALLY be able to say how much it will shorten the life but I think it will. Just don't know how much. Not half though.

Half was a number. From a few pro drivers that I know from when I switched told me that charging over 5 amps shorten the life considerable. I know that my 1s charged at 8 amps have to be replaced sooner then my 2s at 5 amps.

even if its a 8000mah being charged at 8 amps?

When lipo 1st started to get real big in surface rc, there were some studies done on charge rates that showed a relation between higher C charging and lipo cycles (life). There was a definite decrease in lipo cycles as the charge rate was pushed higher and higher.

We been through at least 2 generations of lipo media since then (the 2C safe media and now the 5C capable media). I haven't seen any new testing data and just assuming the new 5C capable lipos have the same cycles vs charge rate character is prob not right. I don't believe Neuenergy or Hyperion would release lipos and say that 5C is ok if cycle life was substantially shotened at the higher charge rates. The older gen lipo when charged at higher C rates would get hot, these new ones from what I'm reading don't get warm at the high C rates. Go to a elec plane based forum - these are the guys that are pushing and driving these changes, they want a lipo back in the air in 10-12mins even if its 10000mah, this is where 5C charging is hot topic.

The biggest time savings is supposed to be in jumping from 1C to 2C. Going from 2C to 3C saves only a few more minutes due to the CC/CV charge routine. And as pointed out, lipo charge rates have outrun charger and PS capabilities. I'm sure we're going to see more powerful chargers coming out, 6 months ago you could harly find a rc oriented 40a PS, now they're easy to find. Some of the high cell counts, large capacity lipos are going to need 650watts or more to charge at 5C. Thats about 2x whats out there today.

The fact that they can be safely charged at up to 5C rates - for charge times as low as 10 to 12 minutes - is just icing on a very tasty cake.

http://www.allerc.com/product_info.p...oducts_id=4562

-Pulled from this ^

I do not intend on even attempting this, i just wanted to fully understand

i think its alot more effective to buy a computer power supply that can handle those high currents with minimal modifications.

i have an ollllllllllllllllllllld 300w power supply from antec that is rated for 35 amps on the 12v rail.

what are the prices for a reasonable rc power supply?

in the old days on nicd/nimh we went to higher amps for punch (screw long life for the win )but lipo doesn't work like that

the only reason to charge at more than 1c is if your race starts too soon for the battery to charge

otherwise you are killing it's life for NO benefit

Guys I run the new Hyperion packs. I run the 3300mah 35C 6S packs. I have chargered it at 15 amps twice just to see if there was any difference, I saw none. The pack did not get hot or anything. I normally charge at 2C 6.6amps. The reason I do this is why force the packs to take that much power when you have time to charge. Here are normal charge times in a perfect world.

1C = 1 hour
2C = 30 min
3C = 20 min
4C = 15 min
5C = 12.5 min.

As you can see you only get a huge increase going from 1C to 2C.

You should buy a charger that will charge 2 packs at once and charge them at 2C that would be the same overal time as 1 charger charging 2 packs at 4C.
http://www.teamhelotes.com/catalog/i1267.html



Here is a good price on a 43 amp power supply, plenty of power to runn the best charger on the market.
http://www.teamhelotes.com/catalog/i1422.html

What charger did you use to charge a 6S pack at 15 amps? Reason I ask is that would require a 378 watt charger if I’m not mistaken. The one you mention is only 180w per side.

Your charge times, do they include the CV portion of the charge, or just the CC part?