guys, 

I want to charge 4 1.500mah batteries in parallel, I heard on some posts and youtube videos that ideally we need to charge the batteries at 1C in this case 1.5A.
charging 4 batteries means 6a, I tried and monitored my charger for few minutes, after 20min it gets REALLY hot, I don´t think is a good a idea to charge on that rate.

Is there any issue for the batteries if I charge them with something like 4.0a (basically 1A for each) ?
I guess should be ok, will just take longer to charge right ?

That is correct. You can charge below 1C. In general, If you charge 1 battery at 1A it will take 1 hour to replace 1000mah. So charging your 4 lipos at 4A may take as long as one and a half hours (if you need to replace 1500mah on all 4 batteries). It will probably take less because you probably won't have discharged them that far.

What charger do you have? My ISDT and PSU stays cool even at 7.2A. You are like taxing your charger beyond it rating.

I would think that the charger is smart enough to not draw/provide more power than what it can handle. 6A is about 16.8*6≈100W.

(23-Jul-2017, 07:25 AM)oyvinla Wrote: I would think that the charger is smart enough to not draw/provide more power than what it can handle. 6A is about 16.8*6≈100W.

I have another charger that when I charge close to the max output, the charger becomes pretty hot. So it is likely he is charging to almost max output or over it.

(23-Jul-2017, 07:25 AM)oyvinla Wrote: I would think that the charger is smart enough to not draw/provide more power than what it can handle. 6A is about 16.8*6≈100W.

The charger is the imax b6ac 80W
And on this example I´m using 3S batteries, in that case 4a * 12.6 = 50W
In theory even if I put 6a would still be 75.6W, bellow the 80W nominal max power. but 6A allow me to fry an egg on it :-)

Still sounds strange that it gets so hot.
What's the input voltage range of your charger? (Or does it have a power supply inside?)
Might help to regulate the input voltage to a level where it doesnt have to work as hard to make it the right voltage for the Lipo charging?

Thinking out load here

(23-Jul-2017, 04:55 PM)flabombarda Wrote: The charger is the imax b6ac 80W
And on this example I´m using 3S batteries, in that case 4a * 12.6 = 50W
In theory even if I put 6a would still be 75.6W, bellow the 80W nominal max power. but 6A allow me to fry an egg on it :-)

I have the same charger. It is rated at 50w and not 80w. If 3S 50w/12.6v = 3.96A. You are charging over max watt. I have charge at 3.5A without issue.

i've used this charger for a long time first Lipos for ASG (3s), then i moved to quads and charged first 3s batteries one by one, then i got parallel board... it was good if i stayed in area of 40-45W, above that it was hot. Some time ago i moved to isdt 150 charger + replaced plug on one of the old laptop chargers (135W) and ... now it rocks...
if you want to charge in parallel get a decent charger. (and belive me i tried to avoid spending those $, now i wish i moved to the better charger earlier)

also calculate how many batteries are you going to charge at the same time and what type they are (graphene batteries are accepting more than 1 C and live happy). As i moved to graphene only benefit i see is the charging speed (and it is worth it) 1h = 4x 1500 mah 4s batteries maxed again)

(23-Jul-2017, 10:08 PM)Grisha0 Wrote: i've used this charger for a long time first Lipos for ASG (3s), then i moved to quads and charged first 3s batteries one by one, then i got parallel board... it was good if i stayed in area of 40-45W, above that it was hot. Some time ago i moved to isdt 150 charger + replaced plug on one of the old laptop chargers (135W) and ... now it rocks...
if you want to charge in parallel get a decent charger. (and belive me i tried to avoid spending those $, now i wish i moved to the better charger earlier)

also calculate how many batteries are you going to charge at the same time and what type they are (graphene batteries are accepting more than 1 C and live happy). As i moved to graphene only benefit i see is the charging speed (and it is worth it) 1h = 4x 1500 mah 4s batteries maxed again)

No doubt a better charger is best. Everyone was recommending the imax when I first started. But if I had to start again, isdt with PSU is only a little bit more, but so much more value as far as charge capacity.