My son has a ride on car. It has a 6 V 7 Ah battery. For charging this battery I use a 7.5 V 1000 mAh charger. Pls tell me how long I will have to charge this battery by this charger (as the charger is 7.5 V). Usually I charged it for 2.5 hours and it was not bad to operate the car (run smoothly minimum 30-40 min). But I would like to know the exact charging time so that the battery will remain okay.
Assuming your battery is Lead Acid chemistry - the charging curve should be constant (as far as I remember).
At 1Ah, I assume it'd take around 7 hours.
The charging time depends on how much the battery was discharged.
Do you operate the car until the battery is so weak that the car does not go? Then a charge will take about 7 hours and the battery will be damaged by being discharged too far.