If you have a motorized RV, your chassis battery, like your car or truck, will most likely be maintenance free.
But your house batteries will need to be maintained with distilled water (only). We’ve looked at a lot of coaches recently and it seems that house battery compartments were someone’s idea of a joke. It’s difficult to reach the battery that is in the back of the tray especially. Here is an automatic watering system by Flow-Rite that makes life so much easier.
The only thing that makes me mad about this unit is that it doesn’t come with a filling bulb. How dumb is that.
And the pump is a bit more difficult to find. You can order it directly or find it at Camping World