That’s really reassuring ! 
Thanks though, that’s a really nice recap. Took me days to find all that information here and there across the forum. About charging, the problem goes away when you install a BMS, which I’ll probably do.
Are li-ion safer ?
Damn, the good deal on graphene batteries: https://hobbyking.com/en_us/turnigy-graphine-5000mah-5s1p-45c.html
BMS are far from failsafe, don’t blindly rely on it
Got it, but what I meant is that charging a battery is way more easier when you have a BMS installed with the battery on the board itself, no need to unplug anything.
I ran into that charger though I read some reviews online, seems to be ok. But I have no idea how to calculate the time it would take to charge a 5S 5Ah battery with that charger. I’ve still not decided yet between external battery charger/balancer or BMS.
IMO, even with BMS especially with lipo you have to check individual cell voltages fairly often. This is where 1 parallel group is nicer.
I don’t think BMS can correct large voltage differences. This along with the low cycle life… I would check the cells often.
So the theory is, it takes 1 hour at 1a to send 1ah to the other side (ah is amp-hour). A 1C charge rate for a 5ah pack would be 5a, and if that rate were maintainable, would charge the pack in 1 hour. In practice though, charge rate tapers off as the pack gets more full, and the balancing stage of the charge, which occurs when the pack is almost full, can take longer if cells are out of balance.
From the listing,
At 5ah, if you’re being nice to the pack you’re going to do a 1C charge which is 5A.
5 x 4.2v = 21v (voltage will vary throughout the charge, 21v is the highest).
50w / 21v = 2.38A
So you’re going to hit the 50w limit not the 6A limit. 2.38A is roughly 1/2C. Which puts you at 2 hours minimum from 0% to 100%. Probably more like 2.5 hours.
If you’re charging 2 x 5s1p 5ah (parallel charging), that’s 10ah and it’ll take twice as long.
Thanks ! 2.5hrs isn’t that bad, plus I will probably never go down to 0%.
Well, if you use BMS for charge and discharge, I don’t see how the cells would become badly unbalanced.
When buying a charger like this one
I do need an external DC converter to plugin to it, right ? Does that DC converter needs to be the voltage of the battery I need to charge ? So say if I’m charging a 5S battery, I need a 18.5v DC converter ?
No. The AC to DC converter output voltage won’t matter as much. The charger handles the voltage 1s to 6s.
I think my converter inputs 12v and I charge 6s
Gotcha, so that means if I find a cheap laptop charger or whatever, it would be all good then.
I have a question regarding the balance charger I bought and what ac to dc converter I need to get.
I bought that charger
Can I get that kind of power adapter ?
Of course I’ll have to make some changes so I can plug it in to the balancer charger. But it’s that kind of thing I need, right ?
That looks way over powered though, and out of the price I would like to put in 
I actually didn’t do any calculation, I should have.
I need to charge a 5S 4.5Ah battery. I read that I should charge a Lipo battery at 1C so that’s 4.5A.
5S is 18.5V when fully charged. That’s 83.25 watts max. I think it’s how it works, is it ?
350W seems a bit too much. I know too much is never bad, but I’m kind of reluctant to throw $50USD 
I mean you don’t need a large power supply for your current setup. But down the road if you want to parallel charge multiple packs of the same type or you get larger batteries you could charge faster.
This is another option. You just have to make your own output wires from the 12v output. It’s a smaller version of what I use. Basically any desktop computer power supply does this.
https://www.bestbuy.com/site/evga-400w-power-supply/5597204.p?skuId=5597204
I was just thinking at that too. It’s cheap and powerful enough. What connector are you taking power out off ?
Looking at that schematic
It seems that either ATX, Molex or PCI Express connectors would be the best ?
I actually have a car battery charger. I’m thinking about going crazy and use it… It’s 12V 15Amps. I also found a car cigarette lighter adapter, totally forgot about it. It outputs 12V at 5.8A, but it’s too low.
Somewhere in the wiring diagram it gives the amp output for each connector. So wire a few up together.
