.jpg)
Question:
What is the best advice for storing RV batteries in the winter?
Answer:
This is a common question, and one that's very often misunderstood. The “quick” answer is to remove your battery or batteries and take them inside a climate-controlled garage for winter storage. However, this is not always practical or convenient for customers who store their RVs in places remote from their nice, warm homes.
.jpg?width=1921&height=1080&name=20241206_CORP_Social_Ask_A_Tech_16x9%20(1).jpg)
There are many types of RV batteries on the market today. Lithium batteries, for instance, are becoming very popular with the advancement of solar and inverter systems. If you use any type of battery for your RV other than a deep-cycle marine/RV battery, then my best and only advice for you is to follow the manufacturer’s recommendations regarding how to store them in Winter.
Email your question today! AskATech@CampersInn.com
However, if you use liquid-filled deep-cycle marine/RV battery or batteries in your RV, keep in mind that plain water will freeze at temperatures below 32 degrees Fahrenheit. New batteries come with electrolyte added to obtain the precise and proper specific gravity of 1.256 ratio when the battery is fully charged. The electrolyte, when at the proper level, acts as kind of an “antifreeze” for deep cycle batteries when fully charged. When batteries are used, or become discharged, the specific gravity of electrolyte is reduced, effectively reducing the water’s ability to remain liquid in freezing temperatures. In other words, when a battery charge level is depleted, the liquid begins to turn back into H20, which freezes when temperatures drop.
Most RV owners do not have the equipment to measure specific gravity ratio in their batteries, however most of us can tell if a battery is starting to get worn out. Aging batteries show obvious signs of wear for instance, when they do not seem to charge up fully or as quickly. There may still be some storage capability left in the battery but it’s getting less useful if it obviously does not “hold” a charge.
To keep a deep-cycle battery from freezing during winter storage, many RVers simply store them with a Battery Tender connected to the terminals. A battery tender is a low-current charger that maintains the fully charged level by “cycling” the battery cells. These are typically safe to use and designed to sense when the battery is fully charged. Battery tenders are designed to place a small “load” on the battery when not charging to “exercise” the battery. When the battery is exercising, it is much like our body. It is healthier and lasts longer.
Another way to exercise the battery(s) is to leave the RV’s power cord connected to an AC power supply. If you leave the power cord connected while in storage it is good practice to leave a compartment light “on”. This provides enough of a “load” to allow the battery to cycling or exercise. And, since the specific gravity level is constantly maintained, the battery does not freeze when temperatures drop.
Always store RV batteries with the top(s) clean and dry! Dirt and moisture between the battery terminals can become a connected “load” which can discharge the battery while in storage.
In summary, if you must store your deep-cycle battery or batteries in freezing temperatures and/or still connected to your RV, follow these steps:
- Place the RV in storage with the battery(s) fully charged.
- Be sure the top(s) of the battery(s) are clean and dry! Dirt and moisture can become a “load” which discharges a battery
- If possible, connect a good-quality battery tender (plugged into a 120-volt outlet) OR leave the power cord connected. The power cord activates the on-board converter/charger to keep the battery topped off. Note: If using the on-board converter/charger OR a battery tender, it is best to place a small load (Example: a single compartment light) to allow the battery to “exercise”.
- Do NOT leave an un-controlled battery charger connected that could over-charge the battery! This could cause a dangerous gassing situation which is extremely flammable!
- If no CONTROLLED (smart) charge source is used (converter/charger or battery tender), turn off any connected load by shutting off the battery disconnect and/or removing the ground cable from the battery.
There is no 100% fool-proof way to ensure the battery survives an extremely- cold winter without keeping it in a climate-controlled room away from moisture and dirt. But if you follow these steps, chances are your battery(s) will be charged up and ready to go when you are ready for the next camping season!
-Keith Marshall, Master Certified Technician
Have questions about your RV? As the RVer's Trusted Resource, we're here to help! Email your RV-related questions to AskATech@CampersInn.com, and our expert will provide answers to keep you on the road with confidence. Send your questions today!
Disclaimer:
The advice and suggestions provided in our "Ask an RV Tech" blog are for informational purposes only and should not be considered a substitute for professional diagnosis or repairs performed by certified technicians. We are not liable for any damage or issues that may arise from attempting to apply the information provided here. For the safety and proper care of your camper, we strongly recommend visiting any of our dealerships to have a certified RV technician diagnose and address your camper's specific needs. Remember to always refer to your RV's manual for additional resources.
