Yes, once you look at cost over the life of the battery and not just the price tag. How many cycles a Millertech LiFePO4 battery gives you depends on how deeply you drain it each time: up to 10,000 cycles at 30% depth of discharge (DoD), 7,000 at 50% and 5,000 at 80%. An AGM battery gets 600 to 800. Add a 10-year Sport Series warranty, and lithium costs less per trip than replacing lead-acid batteries every few seasons.

The batteries are very water resistant, with an estimated IP67 rating. This means they can handle rain, spray, and short-term exposure to water, like when washing a boat, but they are not fully waterproof. As long as they aren’t submerged or continuously sprayed for long periods, they should be fine.

Yes, with enough battery and an inverter big enough to start it, but it takes a lot of power. A rooftop air conditioner often draws 1,000W to 1,800W while it runs, so one 12V 100Ah battery would run it for roughly an hour. RVers who want air conditioning off the grid usually build a larger battery bank, add solar, or run the generator for the hottest hours. Call our Support Team at 855-MAX-LITH and we’ll help you size it.

A standard Sport Series battery won’t take a charge below freezing. Built-in low-temperature charging protection stops it, which protects the cells. Store and charge it above freezing, or bring it inside the night before. If you charge on the boat in the cold, choose a heated model. Millertech offers several options that are heated.

Many RVers do, especially when the new battery drops into the same Group 24 or Group 31 box. Turn off shore power, solar and the battery disconnect first. Connect with ring terminals on the M8 terminals and tighten them to 10 ft-lb. Then check that your converter, solar controller and any DC-to-DC charger are set for lithium (see question 41). If you’re not comfortable with 12V wiring, have your RV service center do it, or call our Support Team at 855-MAX-LITH before you start.

Yes. A solar panel can stay connected to keep your Millertech battery topped off while your RV is parked. Set your solar charge controller to its lithium setting, or use a user-programmable setting set up for lithium. Turn off or disconnect everything else, so detectors and other small loads can't slowly drain the battery. Not sure how to set your controller? Call our Support Team at 855-MAX-LITH.

Yes, in the same RV, but not in the same system. Never connect lithium and lead-acid batteries in parallel with each other, and avoid connecting them in series except in an emergency. Each type can still help the other in a pinch: a lead-acid battery can jump-start a dead lithium battery, and a lithium battery can jump-start a dead lead-acid battery.

Yes. A Millertech battery can be mounted in any position except upside down, and it's fine to install it inside your RV.

Yes! Millertech offers reliable lithium batteries for boats, trolling motors, RVs, and more. Our team can help you find the right replacement, backed by our 10-year, no-questions-asked warranty.

Yes, through an inverter, for short runs. These appliances pull 1,000W or more, so they empty a battery quickly, but a few minutes of use is easy. One 12V 100Ah Sport Series battery handles 100A of continuous current and up to 300A for five seconds. For bigger loads, connect two or more batteries in parallel.

Yes. Your batteries run lights, fans, the furnace blower and the fridge’s controls silently all night, so the generator can stay off through quiet hours. When you do run it, lithium takes a charge quickly, so runs can be shorter. Add solar and some campers skip the generator altogether.

Yes, with the right battery. To power 12V hydraulics, use a Millertech Dual Purpose battery. It will run your leveling jacks, awning and slide-outs.

No. The heater turns on only when a charger is connected and the battery is below 32°F. It warms the cells, then charging starts.

Most RVs use the same 12V house system, so the same batteries work across them. The differences are in charging:
• Travel trailers and fifth wheels: charging from the tow vehicle is limited (see question 42).
• Motorhomes: the engine’s alternator can charge your house batteries, but only if its output tops out at 14.6V or below.
• Camper vans: space is tight, so the smaller size and lighter weight of lithium matter most.
Tell our Support Team what you drive and we’ll match a battery to it.

• Charge the battery fully.
• Disconnect every load and cable, or leave a solar panel connected with the controller on a lithium setting (see "Can I Leave My Solar Connected While My RV Is in Storage?").
• Store it with nothing else attached.

LiFePO4 loses only about 1% to 3% of its charge per month, so it holds its charge well through the off-season. Millertech's winterizing video walks through it.