An camper battery is critical for operating its lights, the water pump and any other appliances that might be inside and which you rely on for comfortable camping. There are three different options when it comes to charging camper batteries--a charger, a relay and an isolator. Which one is best for you depends on your camping style, your budget and your handiness when it comes to working with your camper's engine.
Chargers
If your usual style of camping involves going from RV park to RV park where electrical hookups are readily available, a battery charger makes perfect sense for use when your RV is not in use or is being stored. Make sure to regularly check the water levels in the charger, and that the charger is meant to handle batteries less than 14 volts. Chargers designed for batteries greater than 14 volts will wind up overcharging the battery and boiling off a large portion of the battery water. Battery chargers for camper batteries can be purchased for about $60.
Isolators
Battery isolators are devices that let the battery charge using the camper's alternator when the engine is running. When the engine is turned off, the camper battery and the alternator are disconnected from one another, or "isolated." Isolators can be purchased at most camping supply stores for about $30.
Relays
Relays provide an alternate way of charging the camper battery using the same principles as a battery isolator. These basic switching devices connect the engine and camper batteries together when the engine is running via a current that flows when the ignition is turned on. The current stops when the ignition is switched off, effectively disconnecting the two batteries. If you choose to use a battery relay device, be sure it is a continuous duty relay rather than a starting relay. Retailing for just under $50, relays cost a bit more than isolators, but many argue that they are easier to install.
Tags: camper batteries, camper battery, charging camper, engine running, than volts