I just started using 5S (18V) batteries which takes about 1 hour to charge at home from 120V AC input. In the field, using 12V input, it is taking 2 hours to get charged. I am using a Triton charger which says it charges up to 6S. With 3S I can get the same charge time at home and in the field. Seems to me that using 12V to charge a 18V battery is the problem. Is that right? Thanks. Alex

Possibly. Your charger may provide charging voltages greater than 12 volts. I don't know. Mine does not. It runs from an external 12V power supply so it performs about the same either way, although I don't charge anything more than 4S personally.</p>

Depending upon which Triton you have :

The max power might be the limit. It may not have anything to do with the output being greater than the input. All the Tritons will go higher on output voltage than input voltage.

The EQ series does have more power on DC than AC

My Triton is the EQ. I am using the default charging rate and I read today it is possible to increase it. I will check the manual. Thanks[8D]

The Manual says:

Notes about charging LiPo, Li-Ion, and LiFe batteries:
• TritonEQ automatically sets the charge current based on the battery’s 1C rating. For example, if a capacity of 600mAh is entered
TritonEQ will set the charge current at 0.6A (600mA). For a capacity setting of 2500mAh, the charge current will be set to 2.5A
(2500mA), etc.

• For lithium based batteries rated at 11.1V or greater, the actual amount of current delivered to the battery might be reduced due
to the charger’s maximum power limitation rating. Various circumstances such as battery condition, low input power, etc. can
contribute to such a condition. This is normal.

Then, if using 5S batteries, better having 3 or 4 batteries charged at home. Or wait for 2 hours for charging at the field.[&o]

Something is up then because it has 50 watts on AC power and 63 watts while on dc power. It should be able to make about 2.5-3 amps in the field. Maybe it is the cv or balancing that is taking so long.

The Manual says:

"Notes about charging LiPo, Li-Ion, and LiFe batteries:
• TritonEQ automatically sets the charge current based on the battery’s 1C rating. For example, if a capacity of 600mAh is entered
TritonEQ will set the charge current at 0.6A (600mA). For a capacity setting of 2500mAh, the charge current will be set to 2.5A
(2500mA), etc.

• For lithium based batteries rated at 11.1V or greater, the actual amount of current delivered to the battery might be reduced due
to the charger’s maximum power limitation rating. Various circumstances such as battery condition, low input power, etc. can
contribute to such a condition. This is normal."

Then, if using 5S batteries, better having 3 or 4 batteries charged at home. Or wait for 2 hours for charging at the field.[&o]

I didn't think any of that applied to your problem (it is all true) because you had a 1 hr charge on ac and a 2 hr charge on dc. Normally if you can get your 5S charged in an hr on AC power then there's no reason it can't be done on dc as well since the charger has slight more power output on dc.

Thanks, guver. But makes sense to me that to charge a 18v battery using 12v input is complicated. That's why the manual says:

"• For lithium based batteries rated at 11.1V or greater, the actual amount of current delivered to the battery might be reduced due
to the charger’s maximum power limitation rating. Various circumstances such as battery condition, low input power, etc. can
contribute to such a condition. This is normal."

Thanks, again.

That's a bit misleading. The bottom line is that the power limit is HIGHER on dc than on ac. The charger will not reduce the rate on dc power if it is low, it will simply quit at 10.5 volts input.

Lets back up to your first post. The 1 hr charge on ac is normal. The 2 hr charge on dc is not. It has nothing to do with input power or voltage and really shouldn't have anything to do with dc power either. To verify this hook it up to a car battery and see how long it takes (or verify the rate)