The current could be led off to charge the batteries.
They were only allowed to surface by day to charge the batteries.
In addition, the engine took a full day to charge the batteries, using half its power.
Her commander decided to stay in position for one more day to charge batteries.
No longer did the submarine have to show herself to charge batteries.
"I forgot to charge the batteries in the cell phone."
Direct current is used to charge batteries, and in nearly all electronic systems, as the power supply.
Early in the morning of 29 August, she at last cleared the area to surface and charge her batteries.
To power the equipment, a generator, taken from an old car, charged the batteries.
In such a system, the panels charge the batteries continuously.