Is my battery really good? I had a customer who was having trouble with his battery power in his camper. He said his battery was fine and it had 12.4vdc when he checked it with his voltmeter. Despite this when he attempted to run his slide out in he would lose power in the coach. There are many possible explanations to why this could happen however in this case the answer was right in the battery reading on the voltmeter. Did you know that a battery reading of 12.4volts indicates that your battery is 50% discharged. Due to the fact that the slide out motor requires heavy amperage to run this was causing the camper to run out of power. The battery would not hold a charge after being fully charged and then properly tested so it was replaced then everything worked properly. The lesson to be learned in this instance is do not be fooled about a battery that reads 12volts and think it means that the battery is not the problem.