imax b6ac charger - really slow?

[RVD]

i live in the US (120v outlets) tried using my imax b6ac charger last night. i bought it a few years ago but never got around to using it. i am pretty sure that mine is a real one (authentic) but i suppose it could be a fake. i bought it on hobbyking and they said it was authentic.

when i plug into the wall and try to balance charge, store, or discharge my 6s 5ah lipo, it takes forever. yesterday i spent some time in storage mode to get the cells from 4.1v each to around 3.8v and this thing literally timed out after 2 hours and still wasn't done. for kicks, i started up the storage charge again and it eventually did finish around 100 minutes later...so basically this thing took over 3.5 hours. i think set it up to balance charge from 3.8 and it took another 2 hours to get up to 4.15 an then i just stopped it (i believe it is set to go up to 4.2v but not sure how to change that). i then took it back to balance again and after about 90 minutes it had gone down to 4.0v so it was taking forever again.

is this charger really this slow? is it because i'm on a/c power? should i use 12v DC power instead?

the amp setting for charge is set to 5 amps but it only goes up to around 2 at most while charging and when discharging it is set to 1 amp but it usually hovers at around 0.2-0.3 amps.

i have another charger (hyperion 1420i) and this one was supposed to be more of a backup but i want to use both to run some refresh cycles through a bunch of batteries that haven't been used in years.

 

[Gregory]

Isn't that a 50W charger, and they normally have 5W discharge. I had one at work for NiMH.

the amp setting for charge is set to 5 amps but it only goes up to around 2 at most while charging

Charging a 22.2V pack at 50W is 50W/22.2V=2.2A approximately. So that's normal. Using a DC supply won't change that.

Balancing and discharges can also take a long time with 5W. 5W/22.2V=0.2A. Normal.
My balance chargers faff around for a while with cells fluctuating between 4.19 to 4.22V, if I was in a hurry I would just end charge there.

You know you can change the time out limit in the settings, and try the fast chg setting?

 

[markz]

I got the Imax B8plus model, its 7A and 150W, single channel though.
I can charge from storage voltage 3.85V to 4.15V in about an hour, at 1C, or 5A, on my 5Ah 4S batteries.

Its still quite slow for my liking, so I am pondering a 4 channel or 2 channel. All the 4 channels seem to be 50W per channel, one charger is 60W per channel.
The other 2 channel chargers are a little better, at 400Wx2-$130, 300Wx2-$121, 150Wx2-$90 and 80Wx2-$60.
Dont forget though that with those, also need a power supply unit. I plan on buying the 150Wx2 for $90 from hobby king, its also 7A per channel. I always charge to 1C, so 5A.
But I can bulk charge all 3 packs in one hour. Not bad. I have an old computer desktop power supply unit thats around 11A on the +12V rail, so I will use that, if I can find the cord. If not theres a used junker computer "guy" out of town thats selling old crap for cheap. Ideally I would want 20A+ on the +12V rail. Instructables website teaches you how to build a PSU from Desktop computer PSU. Seems pretty easy. Saves me a $40.

 

[teslanv]

Yeah, that iMax charger is 50W. If your battery is 6S-5Ah (111 Watt-Hours) then it will take a minimum of 2.22 Hours to charge. In reality, the current drops off after about 90% charge, so really it takes closer to 3 hours to charge that 5Ah battery.
Bottom line is, it's just a really slow charger.

Get something faster like an iCharger B106 (10 Amps, 250W) or B206 (20 Amps, 300W) and you can be charging 5-6 times faster.

 

[dogman dan]

Agree with the above, a 50w charger takes lots of time to charge a 100 watt hour pack, 2+ hours. Then balancing, if you do it every cycle adds another half hour.

I found two of the 150w chargers worked ok for me. Running on a 350w meanwell power supply, I had plenty of power leading into them, so together I could charge at 300w. I had an 8 pack, 750 wh battery then, so I could split it in half, and charge each 375wh section at 150w, and get er all done in about 2 hours since I did not usually use it to bone empty.

 

[RVD]

thanks for the info. i guess this is just slow because of the 50 watts. not really a big deal i suppose as i can just use it primary to balance cells maybe? is this charger accurate enough for at least that purpose?

i also have a hyperion 1420i that i use (that is much faster) but last night it seemed like the % readings were a bit all over the place. i need to run a few more tests.

i also have an imax b8 and turnigy b8 (both 150 watt 7a chargers) so maybe i'll play with those a little bit as well.

what is the best charger to get for under $200? i typically only charge at 1C and have 5ah packs that i sometimes put into parallel up to 15ah. is it still the icharger 3010b? or is the icharger 206b good enough for my uses? i typically ride lipo on 10s 10ah (6s2p+4s2p) or 12s 10ah (6s2p+6s2p) or 14s 10ah (6s2p+2s2p+6s2p). i'm ok with breaking up packs to charge them.

RVD.