If your car battery’s voltage is below 11.85 and the charger is putting out a 5-amp charge rate, it will take about 12 hours to fully charge the battery with 400 to 500 cold-cranking amps. The same battery will take around 6 hours to fully charge if the charge rate is 10 amps. The lower the open-circuit voltage in the battery and the more cold-cranking amps and time it will take to charge the battery.In fact, you can look for Tata Green Batteries’ car battery price to buy car batteries online.