OFF TOPIC: battery charger

i have a battery charger which has the following specs:

>1.5V DC output
>120mA Output current


and the specs of my rechargeable battery is:

1.2V
750mA

my question is, what will be the exact time for the battery to be fully charged?

in terms of hours or mins..

sorry for my bad english...

batteries are rated in mAh, a 750mAh battery charging at 120mA takes more than six hours to become fully charged