How Far Should You Top Up Your Car Battery. The best way to maintain a long life for your car battery is by recharging it. To keep your car functioning in top condition it is important to ensure the car battery water level is maintained.
As the battery is used the battery acid loses some of it water content which needs to be replaced by topping up the battery to the upper level mark with distilled water. A 12-volt battery contains six cells with each cell. It would make more sense if you can to connect a battery conditioner - but this will require mains charging so you.
Whenever you run your vehicle you need to completely warm up the car through driving.
This is unlike the sort you get in cameras etc - older NiCads especially- which dont like being recharged when not fully discharged. If you only use your car for short trips or keep it parked for days at a time the battery wont have time to recharge sufficiently. The proper method recommended by most battery manufacturers is to add enough water so that the cell plates are completely submerged but not so much that the water is up to the battery case cell cap vents. As other answers have suggested you cant put an exact figure on this because of the amount of variables involved.
