shark14 wrote:
We have a Class C Winnebago View and our auxiliary batteries will not charge when RV is plugged in. Last year we replaced these same batteries thinking it was the age of the battery. The meter gauge in the camper always shows battery power is full, but the batteries are dead. What are we doing wrong?? Are there things to check out?
A voltmeter or set of battery status lights shows fully charged when the CHARGING voltage is 12.6 volts or higher. However, 12.6 volts will take forever to fully charge a battery. A good charger, converter or solar battery controller will charge at a voltage of 14.4 to 15 volts, then maintain at around 13.5 volts.
A battery is being damaged when sitting at less than 50% of full charge. The only electrical way to tell the per cent of full charge is to start with a fully charged battery and keep a count of the amp-hours of electric energy taken from the battery and added to the battery while charging. This device is called a battery monitor. I have one of these
Ebay cheapos and am very happy with it. A search for battery monitors in this forum will provide good information.
I wasted my first set of RV batteries by trusting the idiot lights and the voltage chart for battery state of charge, which is overly optimistic while charging and for hours after charging stops because the voltmeter shows the charging voltage and "surface charge" for quite a while afterward. With the monitor and a modest solar charging system my batteries are always over 80% of full charge.