dumb ass question AGAIN....

[stevek32]

Lipo's, now I have had lipos for a while and always charged on my accucel 6 charger. I have 2s lipos and 6s always charged on the mah rating and cell rating, so for instance my 2, are 430mah so set the charger at 2s (7.4v) 0.4a likewise my 6s set to 6s (22.2) and 4000mah = 4a charge.
But what is c charge rate? I see alot of people say charge at 1c or you can get away with 2c if your battery can take it etc.
my little 2s Lipo say charge 1-3c. But what does 3c equate to? And can I do it on the accucel charger (same as an Imax b6).
Sorry if it seems a really dumb question but its always bothered me that I don't understand the "c" charge option.

[miniadventure]

1 c = 1 x rated charge for capacity of battery (capacity of the pack in Amp hours)

2 c = charging at 2 x etc.

Eg. your 2s lipo 1c - .43A

2c - .86A

I would make sure your lipo can take a higher charge rate (C) this is usually rated on the lipo.

[miniadventure]

your charger won’t be able to charge the 6S even at 1C

Charger = 50W

6S Lipo = 22.2V
Capacity = 4A

22.2x 4A = 88.8W but your charger is only rated to 50 W So will only charge at around 2.2A MAX

2.2A on 4A lipo = less than 0.55C - this means it will take a while to charge

I would recommend a new charger if you want to charge the larger packs faster and also parallel

[Sburv]

dumb ass question AGAIN....

A 4000mah lipo charged are 4 amps is described as being charged at 1C. The same pack being charged at 8 amps would be 2C, and so on.

For prolonged pack life charging at 1C is best. Many people do charge above 1C myself included, but personally wouldn't charge anything above 2C

I could be wrong but I think the maximum output of a B6 IMAX charger is 5 amps so in this case your charger will be your limiting factor.

[stevek32]

Brilliant thanks guys so basically it means doubling up the mahs for 2c or trebling for 3c. Yes not to worried about the 6's Tbh think I will prob leave them alone!!!. Lol but I charge 4x2's in parallel so normally charge at 1.6a so in theory I could now charge at 3.2a for 2c charge rating.?.

[stevek32]

Yep 5a max. But prob looking to keep 6s to what I have normally been doing as I read somewhere if charging in parallel and one Lipo goes bad it can pass across to another Lipo in the link etc and at £40+ a Lipo would sooner not risk it even if I had a better charger. The 2's are only pocket money so not overly concerned about parallel charging them.

[miniadventure]

You could easily charge your 2s lipos at 2C

0.43A x 4 = 1.72A for 1C
3.44(3.5A) for 2C

I personally do not go above 2C but if the lipos are rated at a higher C rating then they could withstand it but im sure it would have an effect on the life of the lipo if done all the time at high C rates.

[450man]

Personally I always charge at 1C if possible but at the field, when I am impatient to fly again, I'll charge at 2C. For my 3S 2200mah batteries for the 450, 2C is 2 x 2200mah = 4400mah or 4.4A. That is the fastest I can charge at with my iMax B6 but I would charge faster anyway.

[stevek32]

Ok peeps thankyou. Something else now therefor bothers me, my packs are rated 20-40c burst 4mins flying time. So if they can handle the huge discharge rate in over 4mins why can they not handle a bigger charge rate.? Just a thought.

[miniadventure]

Personally I always charge at 1C if possible but at the field, when I am impatient to fly again, I'll charge at 2C. For my 3S 2200mah batteries for the 450, 2C is 2 x 2200mah = 4400mah or 4.4A. That is the fastest I can charge at with my iMax B6 but I would charge faster anyway.

Thats right

11.1V x 2.2A = 48.84Watts at 2C which is near enough at the limits of the charger (50W)

I bought a more powerful charger so that I could paralell charge

[Bob H]

Ok peeps thankyou. Something else now therefor bothers me, my packs are rated 20-40c burst 4mins flying time. So if they can handle the huge discharge rate in over 4mins why can they not handle a bigger charge rate.? Just a thought.

It's to do with the chemistry of the batteries and the fact that they will release energy far more quickly and efficiently than they will absorbe it. The 20-40c burst refers to the discharge rate in that the normal maximum discharge rate in amps is 20 x the capacity of the battery but in short bursts (5 to 10 seconds) it can provide 40 x the capacity with no ill effect. The 4 minutes is what the seller has estimated is the flight time you can expect to get out of the battery but take this with a pinch of salt as flight time is determined by much more than just the battery voltage and capacity