5 amp panel mount battery charger & tester for 12v trailer batteries battery life solutions the 5 amp panel mountable battery charger is complete with a button-activated battery and alternator tester for 12v lead-acid batteries and features a 3-step charging process.<br> <br> <b>3-step charging process:</b><br>constant-current charge -- when the battery voltage is lower than set point, it will charge the battery at the max. current which is called quick charging.<br> constant-voltage charge -- when the battery is almost been fully charged, the charger will limit the current automatically.<br> float charge -- when the battery voltage reaches the settled float voltage of 13.5v, it will automatically switch to the float charging condition with the current of 0.1a~0.3a.<br>