If your battery
is the type where you can pull off the covers, you just need to check your water level. If it hasn't boiled dry it is probably still OK. I left my 2004 Casita
plugged in for several weeks once and it did boil dry. I re-filled it and used it the rest of that season, but I ended up having to buy a new battery the following spring. Don't know if your Casita
has the same inverter/charger as mine did.