The battery in your RV could be either a single 12 v or 2 – 6 v batteries wired in series. They can be charged from shore power (110 volt) or buy the tow vehicle (12 volts) while in tow. This is done thru the converter in the RV.
The converters usually have 2 -40 amp fuses that allow for charging of the batteries. If these fuses are blown, the batteries won’t charge. Your RV battery won’t hold a charge if the terminals are corroded. They should be cleaned with a solution of baking soda and water that will dissolve the corrosion. If this doesn’t solve the issue when your batteries won’t charge when plugged in, give us a call.