I need help. Is "battery charging efficiency" phrase grammatically correct? If yes, what is difference between "battery charging efficiency" and "battery charge efficiency" ?
"Charging" is the process by which a battery is charged.
Although "charge" can be used as a verb to describe the process (ie to charge a battery) it can just mean the level of power that is currently held by a battery (eg there isn't much charge left in this battery).
If you say "battery charging efficiency" it sounds like you are referring to the efficiency of the charging process; ie does the battery take 30 minutes to charge, or does it take 60 minutes to charge.
To be honest, "battery charge efficiency" is a bit vague, but I suppose it could be taken to mean the efficiency of the battery, ie how long it lasts in use.
The true opposite of charging is discharging, but you wouldn't really use that word to describe efficiency of a battery because a truly efficient battery wouldn't discharge, it would hold its charge for as long as possible.
If you want to refer to the charging process, use charging. Otherwise, better terms for describing the use of a battery might be:
- Battery efficiency
- Battery life
- Battery usage