Coast 2 Coast Batteries on the Central Coast can test, supply & install batteries for cars, boats, trucks, laptops & phones. Call (02) 4339 4771.. Do not quick charge for more than 30 min. Otherwise, it will damage the battery. 1. Remove the battery and then place it in a pan of water. 2. Remove the battery filler caps. 3. Connect a battery charger to the battery and adjust the charging current as follows. Battery slow charge current. 55D23L (48): 4.5—5.5 A. 75D23L (52): 5.0—6.0 A.