RV battery maintenance

A coach that sat all winter and won’t power the lights usually has a battery problem, not a wiring one. Most of it is preventable with a few habits straight from the Fleetwood manual.

Two banks, two jobs

Fleetwood’s 2019 Class A gas manual splits the batteries in two. The house bank runs the lights and most appliances. The chassis bank runs the engine side. They charge each other in specific cases: the alternator charges the house bank while you drive, and shore power or the generator charges the chassis bank.

The cutoff switch

The battery cutoff on the monitor panel (the manual also calls it Aux) disconnects the house 12-volt loads. Turn the interior lights off before you flip it.

In storage

No shore power? Turn both the house and chassis disconnects off. Plugged in? Leave them on. Either way, check the voltage while the coach sits.

The manual warns that a discharged battery can freeze and be ruined. It doesn’t give a voltage number in that section, so we won’t invent one.

Flooded, AGM, or lithium

Section 9 has more on maintenance and load testing, and it sends you to the battery maker’s manual in your owner’s packet. Follow that one for watering, terminal torque, and replacement. Only flooded lead-acid batteries need water.

Lithium batteries are sealed, so don’t treat them like flooded cells. And don’t assume the stock converter charges them at the right voltage.

When it’s already dark

If the coach is dead right now, the problem fixer walks you through the cutoff and the fuse panel before it suggests buying anything. If you do need a new bank, the calculator’s smallest size is one 12-volt 100Ah pack.