Have you ever wondered how long do RV batteries last? Will it keep your boondocking as pleasant and exciting as you imagined? These are some of the questions boggling newbie RV owners’ minds. And these are all valid concerns.
While there are no concrete answers about an RV battery’s lifespan, you can still make an accurate estimate. This article will provide you with a clearer picture of what to expect, including what you can do to extend your battery’s lifespan.
How Long Does an RV Battery Last?
A 12-volt travel trailer battery can last about two to three days, on average. This battery life reflects normal electric appliance usage, including lighting, water pump, phone charging, running the propane refrigerator, and others.
However, if you want to extend the battery life up to seven days, you can opt not to use the water pump, use as few lighting fixtures as possible, and observe other energy-saving measures.
You can also add batteries to your system or upgrade your power block to a more energy-efficient and higher-capacity unit.
Of course, using more electric appliances and gadgets will drain your RV battery faster. Instead of getting a couple of days’ worth of charge, the battery might only serve your needs in a day or less.
In general, a two to three-day RV battery life is sufficient for most RV owners.
How Different are RV Batteries from Car Batteries?
The batteries in your motorhome are different from what you have under the hood of your car. For starters, automotive batteries deliver a powerful burst of electricity to jumpstart the engine.
An RV battery has a different purpose – keep your electric appliances, fixtures, and appliances running. Because of their unique function, RV batteries do not deliver a substantial amount of energy. Instead, the batteries provide power in lower, sustained, and more controlled amounts.
This characteristic allows RV batteries to discharge lower (or deeper) than conventional car batteries, earning them the name ‘deep cycle’ batteries.
Many deep cycle batteries for motorhomes and travel trailers have a depth of discharge (DoD) of 50%. These power units hold charge up to 50% of their capacity before requiring a recharge, while more advanced units can handle up to 80%.
It is essential to understand that a battery’s lifespan is directly proportional to the number of cycles (discharge + recharge = one cycle) it undergoes. The more frequent the battery cycling, the shorter the battery’s lifespan.
That is why a car battery will only last about three to thirteen months, while an absorbent glass mat (AGM) lead-acid deep cycle battery can last up to seven years. On the other hand, flooded lead-acid deep cycle batteries can last up to eight years.
What Does a Deep Cycle Battery Mean for My RV?
Suppose you have a 100AH RV battery and your motorhome uses five amperes to run all the appliances and amenities. In that case, you can expect your battery to last only 20 hours (100 ampere-hours divided by five).
However, we also said that deep cycle batteries discharge up to 50% of their capacity. That is why the 20-hour expected RV battery life expectancy goes down to only ten hours (50% of 20 hours).
If you have an RV battery with an 80% discharge capability, you can extend its use up to 16 hours (80% of 20 hours).
Hence, you can achieve an average battery lifespan of two to three days if you have a high-capacity battery (higher amperage rating) with a higher depth of discharge (greater than 50%).
Why Does My RV Battery Keep Dying?
Have you been scratching your head asking yourself, why does my RV battery keep dying?
There are many reasons why your battery does not hold its charge anymore. It could be because of age, undercharging, overcharging, parasitic load, or excessive electrical draw. An RV battery that keeps dying can also be due to a lower amperage rating than the motorhome’s requirements.
However, it would blow you away to learn the most crucial reason an RV battery keeps dying is draining the battery’s charge at a high percentage.
For example, if you discharge a deep cycle battery to 80% every time, you can reduce the battery’s lifetime in half. Instead of getting eight years from your RV battery, you will only get about four years.
That is why it is best to recharge your RV batteries once they reach a 50% discharge level.
If you hear someone say, ‘the battery keeps going dead in my camper,’ you might be able to shed some light on the issue.
How Should I Charge RV Batteries?
The best way to maximize your RV batteries’ lifespan is by charging them at their rated depth of discharge.
Moreover, it would help if you can recharge the batteries using a multistage charger. These chargers come with at least three stages of charging: bulk, absorption, and float.
The charger delivers maximum voltage to the battery during the bulk stage until the battery charge reaches 80%. You can consider this stage the fast-charge phase.
The charger then reduces its power delivery to ensure a more efficient battery recharging during the absorption stage. This stage is pretty slow, but it protects the battery against overcharging and other potential problems.
Once fully charged, the charger keeps delivering minute amounts of electricity to the battery to maintain its 100% charge.
Why is a 6-Volt RV Battery Better than a 12-Volt Battery?
Most people do not realize that a 6-volt deep cycle battery is more powerful than a 12-volt unit.
Many travel trailers and RVs have a pair of 12-volt, 81 Ah deep cycle batteries in a parallel setup for a combined output of 162Ah. Some motorhome batteries deliver 88Ah, totaling 176Ah.
If your motorhome consistently draws 10 amperes, the battery system will last 17.6 hours at full discharge and only 8.8 hours at 50% discharge.
Let us take a look at the 6-volt Trojan T-105 flooded deep cycle battery. This battery has 225Ah. However, you will need to connect two of these in a series to provide your RV with 12 volts of power with the same 225Ah rating.
The pair of 6-volt batteries will last a 10-amp-drawing RV for about 22.5 hours or 11.25 hours at 50% discharge.
Using a pair of 6-volt RV batteries will last at least 28% longer than a pair of 12-volt batteries.
How Can You Extend Your RV Batteries’ Life?
Besides recharging your RV batteries the correct way, you can also adhere to the following tips to extend your RV batteries’ lifespan.
Check the system for parasitic loads.
You might want to check your electric appliances and devices that draw power even with your RV engine turned off. Use a different battery for running the various equipment to avoid draining your RV battery.
Examples of RV items that can draw battery power are clocks, pumps, radios, smoke detectors, fridges, antennas, propane gas detectors, and RV control stations. It would be best to have power strips for each device for you to switch them off when not in use.
Monitor temperature and humidity levels.
Check the battery’s water level regularly, particularly in hot weather or during heavy loads. Temperature extremes can shorten battery life.
Always use distilled water to refill the battery fluid. Do not use tap water because it can produce calcium sulfation.
You might want to consider getting sealed lead-acid RV batteries as a maintenance-free solution.
Determining the answer to the question “how long do RV batteries last?” requires understanding how deep cycle batteries work. The battery’s lifespan hinges on various factors, including battery amperage rating, discharge capability, and maximum battery cycle.
Not allowing your RV battery to discharge below 50% can help extend its lifespan. So do check for parasitic loads, observe the correct battery charging process, and manage the battery’s fluid levels. Moreover, you can always choose to replace your 12-volt RV batteries with 6-volt units.