What Size and How Many LiFePO4 Batteries Do I Need for My RV?
There are some simple truths about installing lithium batteries in an RV that get buried by complexities and misinformation. Some may find it beneficial to convert their RV to lithium, while others may not. Whether you’re thinking about making the switch or just want to know the truth, our discussion about installing lithium batteries will clear things up.
You’ll learn about the benefits lithium batteries offer, the best place to install lithium-ion RV batteries, and the other components you’ll need to complete the project.
10 TRUTHS ABOUT LITHIUM BATTERIES IN RVS
Before we start talking about the installation process, there are some simple truths we want to cover that prove lithium batteries are good for RVs. There’s a lot of information floating around and many different versions of lithium-ion batteries in the marketplace. Unfortunately, many people can’t talk about these batteries without broaching the subject of RV solar panel systems. So, let’s clear some things up:
- RV solar systems work best with lithium-ion batteries, but you can use lithium batteries without solar panels. Your RV generator, tow vehicle’s umbilical cord, or motorhome’s alternator can charge them just like the lead-acid batteries you currently use.
- The correct type of lithium battery uses lithium iron phosphate-oxide, not the ones with poisonous cobalt. The battery industry refers to them by their chemical abbreviation: LiFePO4.
- You can install lithium batteries for your house batteries, not your engine starting battery. Most RVs use the Group 27 battery size, but some will use Group 24, Group 29, or others. Your house batteries should be labeled. If not, check your owner’s manual, call your RV dealer or RV manufacturer.
- You can install lithium batteries on any RV that accepts house batteries. They use the same connections that lead-acid batteries have. In addition, LiFePO4 batteries for RVs have the exact dimensions as their lead-acid counterparts.
- The gelatinous substance lets you install lithium batteries sideways, upside-down, and inside your RV without ventilation. Lead-acid batteries contain water and must have ventilation to distribute harmful gasses.
- Once you install lithium batteries, you can use them in temperatures between -4°C to 135°C Fahrenheit (lead-acid caps off at 113°C F). You can charge LiFePO4 batteries above freezing temperatures; they won’t accept a charge below 32°C F.
- Lithium batteries are half the weight of lead-acid versions. Traditional RV house batteries have an average weight of 65 pounds. So if your RV has two 12-volt lead-acid batteries, you could increase your power capacity with four 12-volt lithium batteries without moving the scale.
- On the financial end, lithium batteries cost more at the point of sale, but they’re a better investment overall. The average lead-acid battery lasts around five years. LiFePO4 batteries can last decades.
- In most cases, installing lithium batteries is virtually “plug-and-play.” Many come with built-in battery management system (BMS) in the battery’s casing. In other words, under most conditions, they regulate themselves. However, we still recommend performing a visual check-in monthly.
- The general rule of thumb for lead-acid batteries is to charge them when they reach 50% of their energy capacity. Lithium-ion batteries can limbo lower. Some companies will label their batteries for a specific amp-hour rating, but have a bigger capacity, has a margin of error preventing complete power drainage.
WHAT SIZE LITHIUM BATTERY DO I NEED FOR MY TRAVEL TRAILER?
You need to know some other simple truths to determine the lithium battery size you need for your travel trailer or motorhome. Most RVs on the road today use Group 27 batteries. Some of the Classic Era (1971-1989) or earlier may use Group 24, Group 29, or Group 31 versions. One of the few components to standardize in the RV industry by the late 20th century was the house battery.
Generally, RVers keep it easy by purchasing 100 amp-hour capacity batteries for two reasons:
- It makes calculating their total energy storage simple
- The battery industry makes more of them
Lithium-Ion batteries come in 12, 24, and 48-volt versions. You’ll find them with capacities between 50-500 Ah.
If you check your RV’s house battery bay, 50-amp RVs (ones with the 4-prong shoreline) have two 12-volt batteries. 30 amp travel trailers and motorhomes (3-prong electric cords) have two 6-volt batteries. Those with the higher amperage may feel they don’t have anything to worry about, but many 30-amp RVers may have concerns about installing lithium batteries.
HOW DO I INCREASE THE CAPACITY OF MY RV BATTERIES?
Most RVers want to know how to increase the capacity of their RV batteries.
It’s been hard to find a campsite during the Remote Period of the Modern Era’s (2020- Present) RV boom. Dry camping has become a substitute for campgrounds and has its RV lifestyle advantages.
Installing lithium batteries in multiple sets increases your power needs for longer duration. To do this correctly, you must know how to connect the batteries in the proper configuration. There are two ways to do this: parallel or in a series. Using the wrong setup can damage the RV’s electric system to the point where you need to replace all required components.
PARALLEL CONFIGURATION
The positive and negative poles stay separated when installing lithium batteries in an RV in a parallel configuration. This means you connect positive to positive using the red battery cables and the black cables for the negatives. 30-amp RVs must use this configuration to maintain the 12-volt power level.
The advantage of a parallel setup is increasing the amp-hours. If each battery has 100 Ah and you have four LiFePO4 batteries, your RV now has a 400 Ah power capacity. Instead of existing with the bare minimum, you’ll have more power to use more electronic devices or camp longer without recharging.
SERIES CONFIGURATION
50-amp RVs that have high-powered electronics may find a series configuration beneficial when installing their lithium batteries. When you connect the positive pole to the negative pole and vice versa, you’re increasing the voltage output.
For example, if you have two 12-volt lithium batteries in a series configuration, you’ve increased the voltage to 24-volts. So, with the proper precautions, an electronic device that generally uses 30-amps at 12-volts could use 15-amps at 24-volts.
Bringing the amperage down on a high-amp device can save energy. If you want to do this, consult a professional electrician and the electronic device’s owner’s manual to determine if this benefit is possible on your RV. Generally, RVers use the parallel configuration because it’s lower risk.
HOW MANY LITHIUM-ION BATTERIES DO I NEED FOR MY RV?
To determine how many lithium-ion batteries you need for your RV, you have to think about your electrical needs. Every electronic device requires a certain amount of watts/amp-hours. Someone using a teardrop camper for the bare essentials may only need one 100Ah battery. A boondocking family hauling a 43-foot fifth-wheel who doesn’t want to count their watts may need eight so they don’t have to start up their generator.
To give you some perspective here’s a basic chart to help you start the conversation on finding the right amount of lithium-ion batteries you’ll need for your RV.
| #100Ah Batteries Needed | Electrical Needs | RV Size |
| 1 | Charge mobile devices,Coffee marker,LED lights,Radio,Small fan | 10-14ft. |
| 1 | Charge mobile devices,Charge tools,Fans,LED lights,Radio,Small cooking device,Small electric cooler | 10-14ft. |
| 2 | Charge mobile devices,Coffee maker,Cooking device,Electric stove,Fans,LED lights,Medical device,Medium electric cooler/small fridge,Radio | 15-20ft. |
| 2 | Charge mobile devices,Coffee maker,Cooking device,Electric stove,Fans,Large electric cooler/small fridge,LED lights,Medical device,Radio,Small TV | 21-30ft. |
| 2-4 | Charge/use mobile devices,Coffee maker,Cooking device,Electric stove,Large Fans,Large LED TV,LED lights,Medical device,Medium fridge,Radio | 31-40ft. |
| 4-8 | Air conditioning(400Ah+),Coffee maker,Cooking devices,Electric Stove & oven,Large fridge,Large LED TVs,LED lights,Radio,Use mobile devices | 40+ft. |
Have you upgraded your RV by installing lithium batteries? How did it go? For more RV-related information, please go ahead to contact Basen RV battery expert any time.