Quick charge?

[RHurley]

I am new to RC in general so im sure this is a noob question but here goes.

I bought 2 Turningy 5000mAh 4S 20C lipos and the imax B6AC charger from this site. I charged them up for the first time last night and it took around an hour per battery @2.5 amp..

The question is how mcuh higher can I safely go to speed up the charge rate? the charger has a quick charge option but I have no idea if thats something I can use with these batteries.

Any help would be GREAT!

Thanks

[JimClark]

I like 1C which would be 5 amps

[lenny]

You charged them at 2.5 amps for a 5000mah lipo,
That is half there C rate.
1C is 5000Mah and that = 5 amp.
Just like 4500mah would = 4.5 amps for charging.
1C is a good safe charge rate,
In less that info on the cell say they can handle more than 1C.
Fast charge,
I have the same thing on my charger but do not used it.

[bob_t]

On my charger, if I use "fast charge" mode, it will not balance the cells. I use the "balance charge" mode at a little less than 1C. At the price for decent Lipos, I want to keep my batteries happy (balanced !!) and give them a good, long life, even if it takes a little longer to charge them.

[siberianhusky]

I don't balance charge ever at the pond, only before going out then I do balance charge up from storage voltage.
Good quality packs don't need it, I check the voltage of individual cells before charging and the always have .02 or less of a volt difference after a run, then just charge them at about 1.5c no balance, then check them before running and they are always very close, at least as close as they show after balancing.
I wouldn't suggest this for budget packs like Turnigy, Hayin, Gens Ace etc. The cells are not matched well enough from the factory.
To be honest I know for a fact that the DVM I have is more accurate than the voltmeter in my chinese charger, a couple times I've checked the voltages at the balance plug and compared it to the reading on the charger, so I figure anything under .03 difference in voltage is probably as close as my charger could do as thats the difference between my DVM and charger. And the difference is not the same from cell to cell!
Combine that with the fact that they instantly balanced as soon as they are connected to the esc anyway so a couple hundredths is nothing.
This obviously all falls apart if the cells are not matched very well to begin with. Now that I know more my next charger will have an internal battery resistance feature.

[madmikepags]

I have safely charged 5000mah packs at 20+ amps, but would not reccomend it as a regular routine, also my packs are all of the highest quality, hyperion, TP, Dinogy, and I use only FMA chargers that balance, show internal resistance and more safety features than u actually want or need. I would not reccomend high power charging w/out balancing either. I typically charge at 1.5-2c, any lower and it would take too much time to charge all my packs for a day of racing. I would not reccomend charging those turnigy 20C packs you have at over 1C (5 amps)

[siberianhusky]

Ya, my next charger is going to be a PL8, I was sold on FMA after using a Cellpro4s of my buddies a couple of times.
The heli guys swear by them, the boat guys seem to lean towards hyperion. Both top quality units.

[RHurley]

Thanks very much for the info everyone. Im having my first run with it in about an hour and Ill try charging at 5amps when they run out. im hoping I get a ball park of 10 minutes of run time with two 5000Mah. im using the motor the Genesis comes stock with

[RHurley]

OK... Ran the boat today LOVE IT... had an issue of really short battery life.. while recharging them I noticed the charger would not charge them at 5amps even though I set it at 5. The most it would do was 3, and it shut off saying it was full after putting 2390mAh into the 5000mAh battery. so it would seem ill need around 2 hours of charging per battery.

[JimClark]

what is your charger? A 50 Watt Charger?

[lenny]

How long was your short run time ?
And what hull, esc, motor, prop is in the boat setup that you have ?
The esc low volt may be set to high.
And what are the temps on the cell, esc, motor, after a 1 to 2 minute run at full throttle ?
Have any picture of the boat and setup ?

OK... Ran the boat today LOVE IT... had an issue of really short battery life.. while recharging them I noticed the charger would not charge them at 5amps even though I set it at 5. The most it would do was 3, and it shut off saying it was full after putting 2390mAh into the 5000mAh battery. so it would seem ill need around 2 hours of charging per battery.

[RHurley]

2.jpgtemps were hardly warm at all.run time was around 5 minutes the first time, pretty sure both batteries had only half charge instead of full though. im running two Turningy 4s 20c 5000mAh set up so i have 10k. motor is 36-74Size 2075kv Watercooled Brushless Inrunner from hobbyking. ESC/BEC is 200A watercooled skywing. octura 440 prop. imax B6AC charger says 50W max. just goin for long run times. not super worried about insane speed... yet.

[JimClark]

it is your charger that will not let that large of a batt to charge at 1c want faster times then you need a 200 watt charger and a big powersupply

[TristanJones]

You should be getting 10mins easy with those packs, when you get more go for a higher C rating, 50+ is good. I had the same setup and clocked it at 70kmh with GPS.

[RHurley]

so this charger isnt going to charge the batterys to full without me charging each one twice basically, not mater how slow I let them charge? wish I had known that before I ordered it. seeign as how this is my first EVERYTHING I am already at max budget for now. Guess ill just keep an eye out for a bigger charger and start saving up again