USB Chargers and other chargers

Canada EH · April 18, 2018

I am in need of a few extra chargers to charge up my 18650 pack. Currently I have a 6S rc charger that balances quite slow. I purchased a bunch of adapters which I thought were laptop chargers but they are power adapters for printers and such. I bought this random adapter I thought was charger and its acting like one, listed as 12V 2.65A. Sure enough the voltage is increasing ever so slightly in 0.01V increments just like my rc charger. I then look at amperes and it goes from 1.01A to 0.82A but mostly on 1.01A.

I was wondering if that was the phenomenon of "burping" ?

Also I just check, its very close to its max voltage of 4.00V and now the charging current is 0.30A. I think its a good unit then.

I had another unit that stated 4V 1A yet it jumped to 8V and 3A, it was a power adapter for a PS4.

I am going to start buying cell phone chargers now, sure I have to plug a bunch in but they should all be the correct voltage. I need 4.20V for the 18650 form factor, but even if I get them to 4.00V it dont matter.

I was wondering about the USB chargers I see on Hobbyking, dx.com, gearbest.com and banggood.com. Are they CC/CV?

I do have a few Meanwell chargers that I can adjust the voltages, but I cant adjust the current, and the current is far too much for the 18650's to handle. It wont handle 16A when at most its 2C and 2A.

edit - ok ok I will sign up for RCgroup forum they will know instantly!

Hackentosher · April 18, 2018

Woah woah Woah do not just plug power supplies into a 6s battery. The way hobby chargers work is they get your battery close, and then switch from constant current to constant voltage to bring it up to the full 25.2v. When it comes to balancing, the way most hobby chargers work is they bring up the total pack voltage by like 0.01v, then discharge that extra voltage from the cells that dont need balancing. Some chargers are better than others at this when it comes to large packs. My hitec x2ac took about 4 days to balance my 4s14p pack that's about 28,000mah. That's because it can only discharge 100ma on the balance leads. The highest I've seen is 1amp balance discharge power on some nice chargers like the icharger and revolectrix. They work this way because it's the safest way to charge a lithium battery. Plugging a power supply into a battery like this isn't a good plan because it's going to try to output its full power to the load. Do not hook up a battery to a supply unless your battery has a bms to handle voltage cutoff, charging, balancing, etc. A little wall wart doesn't know any better if a cell suddenly becomes super over its voltage threshold. A wall wart doesn't know to shutoff when the pack voltage is at the right level. Also a wall wart can't balance. Please don't do this https://youtu.be/xhMLa38vPoo

Canada EH · April 20, 2018

I have been using a Meanwell PSU for charging my battery pack for years and yes the battery pack has no BMS. There was a fellow who bought a pack with a BMS and his entire house burned down. I babysit my battery, those cheap BMS' you have no clue about, now buying a BMS from say Besttech is great which I might do because I'd prefer a bulk charger and a BMS to balance. Meanwell is a quite popular brand because of the reputable brand quality. I've had a few rc balance chargers now, both from iMax b6 and b8 and they are so slow. I just finished a 3 day manual balance charge on a 13S10P and I noticed a couple with bad IR, voltage was always much lower then the rest. I like to keep all mine at around 0.05V if not exact. I am currently waiting on a 3rd rc charger and then I will be able to easily hook up the sense wires to balance charge each of the 5 sets of 2P I have.

That thing I was using, basically stopped working because I hooked up that polarity wrong. But for $3 it did its job. I figured I will just go ahead and buy a bunch of cell phone chargers and laptop chargers if I can find them cheap enough with the right voltage and current ratings. They are so easy to boost a weak cell.

I would love the 2000W 40A 10S iCharger but they are so expensive, like $350usd which is like $475cdn

http://www.buddyrc.com/charging-systems/charger/icharger.html

Quote

This is the one I'd buy because its 10S and dual port!

iCharger 4010 Duo 2000W 40A 10S Dual Port Charger

$349.95

iCharger 308 Duo 1300W 30A 8S Dual Port Charger

$269.95

i Charger 406 Duo 1400W 40A 6S Dual Port Charger

$299.95

iCharger 3010B 1000W 30A 10S Balance Charger
$189.95

iCharger 1010B+ 300W 10A 10S Balance Charger

$135.95

I liked studying the charging process, How the voltage goes up incrementally at 0.01V increments at a constant current, then it reaches top voltage and current decreases and voltage is Vmax. The thing I dont like is that the cheap RC chargers are always off in their voltage readings by 0.40V from my Multi-meter. I read somewhere you can adjust that somehow by soldering in a resistor somewhere.

Hobbyking has a few chargers I am interested in, I have a few Dell PSU's I power them from, did the mod and isolated the ground.

edit - I just found something interesting, I am going to bulk charger to say 4.10V then use my balance chargers to balance from 4.10V on up to 4.20V. It will save a ton of time and I can do it morning. I just need to solder in balance leads so I can use the voltage reader if I want to view the balance, then unplug that and balance charge.