When you're about to pack up and hit the road, or you love the outdoors like camping, fishing, etc., having a battery that is always powered will enhance your outing experience. It can power the RV to start the engine and power our home appliances for our daily needs, such as cooking good food, lighting up the lights after sunset, and watching our favorite movies in the RV with loved ones. A great battery can give us a comfortable feeling of home even when outdoors. Finding a suitable battery to power will be the first step to starting our enjoyable off-grid activities.
RVers who have started their RV life may have known that there are two general types of batteries in RVs, the starter battery and the deep cycle RV battery. A starter battery is the equivalent of the car battery used to start the RV engine, designed to provide a short, intense, high current. A deep cycle RV battery mainly powers household equipment, designed to provide a stable, constant low current. It typically uses thicker lead plates to withstand repeated discharge and charge cycles. When we consider powering RVs, we are more likely to be thinking about powering household equipment, and deep cycle batteries are an option that we're more likely to choose.
Deep cycle batteries can divide into two main types: Lead-acid batteries and lithium-ion (Li-ion) batteries. Lead-acid batteries include Sealed Lead Acid batteries (SLA) and Flooded Lead Acid batteries (FLA). SLA is also called the VRLA battery, short for a Valve Regulated Lead Acid battery. Among VRLA batteries, there are Absorbed Glass Mat batteries (AGM) and Gel Cell batteries (GEL). Lead-acid batteries are the earliest type of rechargeable battery in existence. The technology behind lead-acid batteries has been for over 170 years, and now it is very mature. Generally, lead-acid batteries are available both in 6 and 12-volt configurations. Lithium-ion (Li-ion) batteries are another deep-cycle RV battery. Compared to lead-acid batteries, it is a relatively new battery type. Lithium-ion batteries are more expensive because the raw materials needed to make them are more challenging to obtain. They often use a 12-volt configuration. There are many different types of lithium-ion batteries, depending on the electrode material and electrolyte used. The common ones are Lithium Cobalt Oxide (ICR), Lithium Manganese Oxide (IMR), Lithium Manganese Nickel (INR), and Lithium Iron Phosphate (LFP). Lithium iron phosphate batteries are known for providing better safety characteristics. Lithium iron phosphate battery, an emerging RV battery, has received a lot of attention since its introduction. We may want to ask, how is it different from the traditional lead-acid batteries? Which type of battery to choose to fulfill your power needs? We will compare lithium iron phosphate batteries and lead-acid batteries in detail, analyzing the advantages and disadvantages of both to understand them more deeply in this article. Now, let's go closer to the world of these two batteries and find the answers.
Space, weight, and energy density
RVs have limited space. We all want to put down as much as we can that we need to use. So battery size and weight will be a frequently used measures. Energy density is the amount of energy stored in each weight and space. Lead-acid batteries have a low capacity density. It means Lead-acid batteries are heavier and bigger for the same amount of energy. Lithium iron phosphate batteries are relatively weighting lighter.
Charging and Discharging Characteristics
Lead-acid batteries usually take longer to charge. Because once they're close to completion, their charge rate slows down. In addition, lead-acid batteries are prone to sulfation problems. Overcharging or not charging when not in use can lead to sulfation. Overcharging can degrade the electrolyte, electrolytically broken down into oxygen and hydrogen. The gas escapes into the battery. The electrolyte becomes more acidic and more likely to corrode the plates. Both electrolyte reduction and plate corrosion reduce battery performance. So using lead-acid batteries, regular charging will help maintain the battery's lifespan.Discharging a deep cycle lead-acid battery to less than 20% (sometimes 50%) will permanently reduce the capacity of the battery.Lithium iron phosphate batteries can accept very high charging currents, so they take less time to charge and can power high-powered appliances. Sometimes they can power multiple home appliances at the same time. In addition, LFP batteries can completely discharge and do not affect their performance. They offer constant voltage over any discharge rate until they run out of power.
Operating Temperatures
The LiFePO4 battery has a better high-temperature performance. Because lithium iron phosphate is incombustible, it can withstand high temperatures without decomposition, so it has better thermal and structural stability. General, LFP batteries do not enter a thermal runaway state until about 270 degrees Celsius. It effectively reduces the likelihood of fire and explosion. So LiFePO4 batteries would be a good choice if frequently stationed in hot places.
Shelf life and cycle life
LPF batteries can withstand deeper discharge, more cycles, and last longer than lead-acid batteries. Lead-acid batteries can provide about 300-1200 cycles, and their lifespans are about 1-3 years. LiFePO4 batteries' cycle is about 2000-5000, and their lifespans are about 5-10 years.
Cost
Lead-acid batteries have been around for over 170 years. The technology is mature, and the manufacturing cost is low. There are ubiquitous suppliers on the market, so we can easily buy cheap lead-acid batteries at malls and auto stores. Lead-acid batteries account for about 40% of the batteries sold in the world. In the early stages, lead-acid batteries were cheaper in terms of capital cost, time, and energy cost. But if the lifetime is taken into account and viewed later, LFP batteries will still be more cost-effective.
Environment Impact
Lead-acid batteries harm the environment. The lead of lead-acid batteries is toxic, and all should be recycled to prevent harm to the environment. However, in reality, 5% of lead-acid batteries are not recycled, which means that millions of tons of lead are dumped into nature and have probably contaminated groundwater. Therefore, although lead-acid batteries bring us a lot of convenience in using electricity, many people still strongly criticize its negative impact on the environment.
Unlike lead-acid and nickel oxide lithium batteries, which are toxic, lithium iron phosphate batteries are non-toxic and do not leak. They have a long life span and do not need to replace as often. So LFP batteries are better for the environment.
Closing words
We have compared deep-cycle lead-acid and lithium iron phosphate batteries from six aspects. As for the best battery, it depends on what factors we value more when buying, the budget we intend to spend on it and how often we use it. The most suitable for our needs is the best. If you are still having difficulty in choosing, the lithium iron phosphate deep cycle battery may be more worth considering, whether its appearance, performance, or environmental protection.