By Brad, owner

Every spring we meet the same RVs twice: once in the fall, when the owner parks it “for a few months”, and again in April, when something didn’t survive the wait. Usually it isn’t dramatic. It’s a cracked water line, a battery bank that sat at zero for weeks, or a solar setup that was never meant to babysit a parked rig through a high-desert winter.

Reno makes this tricky. Our days can be mild and sunny while the nights drop well below freezing, sometimes for weeks at a stretch. An RV that’s fine at 2 p.m. can be in trouble at 2 a.m. Here’s what we look at before a coach goes into storage, and what you can check yourself.

Water lines freeze first

Water is the classic winter failure, and the cheapest one to prevent. Any water left in the lines, the pump, the water heater or the low-point drains can freeze, expand and split a fitting. Often you won’t find the damage until the first time you pressurize the system in spring.

Proper winterizing means draining the tanks and water heater, bypassing the water heater, and filling the lines with non-toxic RV antifreeze. That’s the method we use in our shop. Some owners blow the lines out with air instead, but antifreeze leaves less to chance in a fixture you forgot. Don’t forget the outdoor shower, the ice maker line or a washer hookup if your coach has one. Most leaks we see in spring come from the “forgotten” fixture.

Lithium batteries don’t like charging below freezing

Lithium (LiFePO4) batteries handle cold storage well. They just shouldn’t be charged when the cells are below freezing unless the battery is designed for it. Many quality batteries protect themselves: they have a low-temperature charge cutoff, or internal heating that warms the cells before accepting a charge. Others rely on the charger or the battery monitor to hold back. Check your battery’s specification sheet, or ask us, before you assume either way.

That matters in storage because solar panels and a shore-power converter will happily try to charge on a cold sunny morning. If your system isn’t set up for cold-weather charging, it’s safer to store the batteries at the partial charge the manufacturer recommends and disconnect them completely.

Parasitic loads drain parked RVs

Even with everything “off”, most RVs have small loads that never sleep: propane and CO detectors, stereo memory, control boards, an inverter left on standby. Over a few winter weeks those small draws can pull a battery bank all the way down. A deeply discharged lead-acid battery can even freeze and crack. Lithium batteries usually shut themselves off to protect the cells, which can leave you with a pack that needs a careful recovery charge in spring.

The fix is simple: use your battery disconnect, or make sure there’s a real one between the batteries and the coach. If you’re not sure which switch actually isolates the bank, that’s a five-minute question for us to answer.

Can solar keep your batteries topped up in storage?

Sometimes, and it’s a good use of solar when the system is set up for it. A correctly configured charge controller can keep a parked battery bank healthy through the winter, as long as:

• the controller’s charge settings match your battery chemistry and its cold-weather limits;
• snow or a storage cover isn’t blocking the panels;
• nothing else (an inverter on standby, for example) is quietly drawing more than the panels can replace on short winter days.

If your system has a Victron Cerbo GX connected to the internet, you can even check battery levels from your phone while the RV sits in storage. Our Cerbo GX visual guide shows what that looks like.

A quick storage checklist

1. Winterize the water system: drain, bypass the water heater, then fill the lines with RV antifreeze.
2. Note your battery type and its cold-charging limits.
3. Store the batteries at the charge the manufacturer recommends, then disconnect them, unless your solar or charger is set up to maintain them safely in the cold.
4. Turn off the inverter, and confirm the battery disconnect actually isolates the bank.
5. Clear the roof and panels of covers or debris if you’re relying on solar.
6. Visit once a month if you can: check the battery state, look for leaks and keep rodents out.

Spring should be boring

The best spring de-winterization is a boring one: water flows, nothing drips, the batteries wake up and the monitor shows sensible numbers. If you’d like us to winterize your RV, or have questions about your battery and charging setup before storage, you can request service here. And if you’re thinking about moving to lithium before next season, our lithium battery guide walks through what we check first.