Iām pretty sure none of the Liitokala chargers can do 3A. Why are you thinking they made a high amp charger?
For an unprotected 26650 high drain battery, under 50 milliohms is good.
My cyan and black Liitokala 26650 typically read 30 to 40 milliohms.
Because Iāve misread your messageā¦. 
Itās about Liitokala cells being charged at 3A, instead of a Liitokala charger charging cells at 3Aā¦
Okay, now I understand.
This C4-12 is the first charger Iāve seen with this much power, 12A. Maybe it will start a trend where other charger manufacturers will release high powered versions of their current models. Then we will have choices. :+1:
Today my C4-12 decided to dieā¦
I plugged it in and put two AAA cells to charge and it just went off.
Power supply is good.
Any suggestion what to look for on board?
:cry: . ā¦ If you canāt revive it, may it RIP. :+1:
Good luck fixing it. 
I hope I will be able to do it.
It only charged batteries 20-30 times before it diedā¦so almost new.
/\ ā¦. :+1:
I just opened it up and I can say Iām lostā¦I donāt know what to look for.
Looks like it will rest in peace (or pieces).
It died after little use so Iām not sure about buying another, but I need charger like that.
Since you opened it up, I guess you heard back from Miboxer and they said itās out of warranty?
I bought it over aliexpress, and I think I canāt get warranty.
Or if I can get it but I have to return charger that cost me more than buying new one.
:+1: :+1: :+1: for choices. Always.
If I had choice I would go for something far more simple. No displays with settings. Just one button to set the current and thatās it. Just like the little LiitoKala and Basen chargers.
That brings me to another point. Iāve also bought a simple USB tester that shows me the current draw when charging. I learned something I knew for a long time but never got trough my thick skull.
A 2A (Basen) charger isnāt twice as fast as an 1A (LiitoKala) charger.
Sure 2A goes full throttle when the cell is (nearly) empty, but the more full it gets the lower the current.
Iām not saying thatās bad, or shouldnāt be that way, just that those high currents only matter in the beginning of the charging process. And when the cell isnāt completely empty, you wonāt see high currents at all.
I have no way of doing an honest test but as a way to explain using fictive numbers I expect something like this.
3A: 15 minutes at 3A, 15 minutes at 2A, 1 hour at 1A and below. (90 mins)
2A: 45 minutes at 2A, 1 hour at 1A and below. (105 mins)
1A: 2:15 hour at 1A and below. (135 mins)
So 3A isnāt 3x faster than 1A.
Your numbers are way off. Most Liion chargers use 2 main phases. The CC phase which is constant current and the CV phase which is the contact voltage.
The vast majority of time spent charging a battery (letās say from 3.0 volt) is spent in the CC phase. Maybe 75% of the time.
Once the battery is charged up to around 4.1v or so the charger will shift to the CV phase. The voltage holds at 4.2 and the current starts to ramp down slowly.
The CV phase is always very slow for the amount of power it puts into the battery. This is why you see cell phones say they charge from dead to 80% in one hour. That is the CC phase. It might take another 30 to 40 minutes to get that last 20%.
Lithium tool battery packs usually only charge them up to 4v. This makes them charge faster and the battery life longer.
Same for electronic cars. Tesla only charges their battery packs to roughly 4.0 volt. Definitely not to 4.2v. That just adds charge time and reduces battery life.
You can see these charge cycles by checking out battery charger reviews. Here is a good source.
http://www.lygte-info.dk/info/indexBatteriesAndChargers%20UK.html
In my experience, I weekly tend to run my 26650 cells down to around 3.7 volt. With my old 1A charger Iād be waiting about 5 hours. With a 2A charger it went down to about 3 hours. With a 3A charger itās usually under 2 hours. So yeah, from 1A to 3A is not exactly 3 times faster, but it saves me over 3 hours of having to sit next to the charger either reading or watching tv, etcā¦ which is huge. I get impatient. Iāll gladly pay more money for a faster charger. Lol
5 to 2 hours is indeed worth the trouble. And I pay extra for more speed too. Donāt get me wrong on that. I even decided to not to buy anything below 2A.
Do you really babysit your cells being charged? If yes, then extra time really counts. I just fill my chargers and leave for the day/night. So often I donāt need extreme speed. But there are times I do and need as much as I can.
Whatās most informative in your post is the part about CC and CV.
Say I need to charge 8 cells asap, but I only have one 3A MiBoxer. Then it would be best to charge until about 75% and top the remaining 25% of in one of my slower chargers while the MiBoxer charges the remaining 4 cells at full speed.
Something like that?
You are not supposed to leave charging cells unattended. Thatās one of the rules of Liion batteries. The few people Iāve heard that charge unattended put the charger in a metal pan and put it outside or in their garage in case it catches on fire. There have been people whose house have burned down because they left it charging unattended.
Maybe Iām being a bit too precautious, but itās easy for me to babysit them. Itās usually charge all my main cells once a week. Iāve got the one C4-12 and 2 Xtar SV2 Rocket chargers. So if I need to charge 4 x 26650 at 3A and 4 x 26350 at 1A I can do it all in one setting.
If you need to charge 8 x 18650, your idea from above sounds good and should reduce the overall charge times. Can your particular 18650 take a 3A charge? Not all can. You can look up your particular battery models data sheet to see all its specs.
Here is quick guide Mooch did.
.
I have no clueā¦
On this forum Iāve read 1C is ok, and 0.8C advisable.
All my 18650 cells are 3500 mAh, so with that in mind I bought 2A and 3A chargers.
My LiitoKala 35A 3500 mAh cells arenāt in the list.
Thanks for the nice overview chart JasonWW! May I correct you i.a.w. the Samsung 29E? This one is specified to 8.2A instead of 2.75A.
Cheers, Thomas
Generally speaking, high capacity cells tend to not have very high discharge or recharge rates. What particular battery models do you have?
All praise goes to Mooch. This is his chart. He and HKJ are great resources for the battery community.
BTW, I have never heard of any 18650 being safe to charge at 8.2A. Are you sure about that? Maybe you are thinking of the output?
Sorry for the confusion JasonWW. Of course, I meant the output and not the charge rate. 