For and long life and good capacity from a car battery the batttery has to be filled to the top. Grab a washer or a coin and open the battery. Now fill all compartmens with distilled water (not normal water). Let a little bit space to get the lids back on the battery.
Step 1: Finish
Carefully screw the battery compartments back on and firmly secure. Now enjoy your long life car battery. Look at my other work.