Generally speaking, RV batteries can last for several months in storage without being used before they begin to lose their charge. Lead-acid batteries, commonly used in RVs, can lose around 5-15% of their monthly charge when not being used or charged. Lithium-ion batteries, which are becoming more popular in RVs, have a slower self-discharge rate and can last longer in storage without losing their charge. To extend the lifespan of RV batteries in storage, it's important to properly maintain and prepare them before storing them. This includes fully charging the battery, disconnecting it from the RV's electrical system, and storing it in a cool and dry location. It's also a good idea to periodically check on the battery and recharge it as needed to prevent it from losing its charge completely. If you're not sure how long your RV battery will last in storage, we recommend using a battery tender to keep it charged. This way, you can be sure that your battery will be in good working order when you take your RV out of storage. The lifespan of RV batteries in storage can vary depending on a number of factors, such as the type of battery, the condition of the battery before storage, and the temperature and humidity of the storage environment.