If you’re considering home energy storage, there are several types of batteries to choose from. In this article, we’ll compare two of the most common battery options paired with solar installations: lithium-ion and lead acid. Other than the different materials that compose each type of battery, their main difference comes in terms of cost and performance. Lead acid batteries tend to be less expensive whereas lithium-ion batteries perform better and are more efficient. For years, lead acid batteries have been the “go to” source of power for electronics, vehicles and equipment. However, thanks to several features that promote efficiency and safety, lithium-ion batteries are becoming a popular choice across several industries. Lead Acid Batteries are mostly used onboard ships as emergency power support units. However, lately a widespread adoption of lithium-ion batteries has been noticed. how do lithium-ion and lead acid batteries compare? Lithium-ion and lead acid batteries can both store energy effectively, but each has unique advantages and drawbacks. Here are some important comparison points to consider when deciding on a battery type: Cost The one category in which lead acid batteries seemingly outperform lithium-ion options is in their cost. A lead acid battery system may cost hundreds or thousands of dollars less than a similarly-sized lithium-ion setup – lithium-ion batteries currently cost anywhere from $5,000 to $15,000 including installation, and this range can go higher or lower depending on the size of system you need. While lead acid batteries typically have lower purchase and installation costs compared to lithium-ion options, the lifetime value of a lithium-ion battery evens the scales. Below, we’ll outline other important features of each battery type to consider, and explain why these factors contribute to an overall higher value for lithium-ion battery systems. Capacity A battery’s capacity is a measure of how much energy can be stored (and eventually discharged) by the battery. While capacity numbers vary between battery models and manufacturers, lithium-ion battery technology has been well-proven to have a significantly higher energy density than lead acid batteries. This means that more energy can be stored in a lithium-ion battery using the same physical space. Because you can store more energy with lithium-ion technology, you can discharge more energy, thus powering more appliances for longer periods of time. Depth of discharge A battery’s depth of discharge is the percentage of the battery that can be safely drained of energy without damaging the battery. While it is normal to use 85 percent or more of a lithium-ion battery’s total capacity in a single cycle, lead acid batteries should not be discharged past roughly 50 percent, as doing so negatively impacts the lifetime of the battery. The superior depth of discharge possible with lithium-ion technology means that lithium-ion batteries have an even higher effective capacity than lead acid options, especially considering the higher energy density in lithium-ion technology mentioned above.refer to:12V Lithium ion Battery Manufacturer Efficiency Just like solar panel efficiency, battery efficiency is an important metric to consider when comparing different options. Most lithium-ion batteries are 95 percent efficient or more, meaning that 95 percent or more of the energy stored in a lithium-ion battery is actually able to be used. Conversely, lead acid batteries see efficiencies closer to 80 to 85 percent. Higher efficiency batteries charge faster, and similarly to the depth of discharge, improved efficiency means a higher effective battery capacity. Lifespan Batteries are also similar to solar panels in that they degrade over time and become less effective as they age. Discharging a battery to power your home or appliances and then recharging it with solar energy or the grid counts as one “cycle”. The numbers vary from study to study, but lithium-ion batteries generally last for several times the number of cycles as lead acid batteries, leading to a longer effective lifespan for lithium-ion products. Why lithium ion batteries The reasons why lithium ion batteries are gaining popularity and replace the lead acid batteries on board ships (despite the fact that they are more expensive at initial purchasing) are many: Lithium ion achieves an energy density of 125-600+ Wh/L versus 50-90 Wh/L for lead acid batteries. This means that for same energy consumption a Lithium ion battery may last 8-10 times longer than a lead acid. The weight and size of lithium batteries are much lower in comparison to lead-acid batteries with the same capacity. Charging a lead-acid battery can take more than 10 hours, whereas lithium ion batteries can take from 3 hours to as little as a few minutes to charge, depending on the size of the battery. Lithium ion chemistries can accept a faster rate of current, charging quicker than batteries made with lead acid. Depth of Discharge indicates the maximum energy of a fully charged battery that can be used without recharging. Lithium batteries provide 85-100% of their stored capacity, regardless of the rate of discharge. Lead-acid batteries typically provide less usable energy with higher rates of discharge close to 50% only. Lead-acid batteries are cheaper and are easier to install when compared to Lithium-ion batteries. The price of a lithium-ion battery is two times higher than a lead-acid battery with the same capacity. However, if someone compares the life of the batteries, lithium-ion lasts longer than a lead-acid battery. Hence, lead-acid batteries are cheaper only for short-term applications than lithium-ion batterie Cycle life is the number of charging and discharging cycles a battery can undergo without compromising its performance. Usually, lithium-ion batteries possess a cycle life of 5000, and complete discharge does not affect the life cycle. Whereas a lead-acid battery lasts for 300 to 500 cycles. The complete discharge of the lead-acid battery significantly affects its life cycle. Why lead acid batteries The only area that lead acid batteries perform better than lithium ion batteries are cold climates. Low temperature can cause significant reduction to stored capacity. The lithium ion batteries are not sensitive to capacity reduction however they may face problem to recharging in sub zero temperatures.More:12v 300ah battery Risks and challenges However, both types of batteries hide risks during usage. For example, in both lead-acid and lithium-ion batteries, overcharging may lead to an explosion. Furthermore, the sulfuric acid in the lead-acid battery is highly corrosive, and there is a chance of leakage. If overcharged, hydrogen and oxygen gases may evolve, leading to an explosion. In lithium-ion batteries, there are high chances for thermal runaway. Thermal runaway is the condition that occurs when the heat generated within the battery exceeds the heat dissipated to the surroundings. The thermal runaway also has the potential to trigger a battery explosion. The use of batteries on board is a regulatory requirement mostly for emergency reasons. The type of the battery to be used to comply with the requirements is a decision made by Ship Operators. In any case, there should be an efficient planning and assessment weighting all factors related to battery use, considering Safety, Purpose of use, Support, Performance and Cost. Lithium-ion Batteries Here are some of the factors that influence battery life: Extreme temperatures: Lithium-ion batteries are extremely resilient to high and low temperatures. Lithium iron phosphate, the chemistry used by Flux Power, is especially resilient. We even offer heaters for batteries that will be used in cold temperatures to ensure a longer lifetime for the battery. Improper storage: How a battery is stored can affect its lifespan. Lithium-ion batteries should be stored at a partial charge in a cool place. They should have around a 40% to 50% state of charge when being stored. If being stored for extended periods of time it is important to monitor the battery every couple of months and charge it back up to 50% if it gets too low. Deep cycling: The life of a lithium-ion battery can be impacted by deep cycling. Unlike other deep cycle batteries, partial charges prolong the life of a lithium battery. lead acid Batteries Environmental factors and how lead acid batteries are used also play a significant role in battery life. These factors include: Extreme temperatures: Like lithium-ion batteries, the lifespan of a lead acid battery can be shortened when exposed to extreme temperatures, especially heat. After charging, lead acid batteries require a cooldown period because the act of charging produces high amounts of heat. Water levels: Overfilling water levels in a lead acid battery can cause electrolyte loss, reducing the lifespan of a battery. This can also promote corrosion of the battery, which can cause batteries to unevenly charge, which reduces lifespan. Deep discharge: The life of a lead acid battery suffers when a deep discharge occurs, and the battery is left “dead” for an extended amount of time. Frequently asked questions about solar batteries What is the difference between a lithium battery and a lithium-ion battery? Lithium batteries are designed to be single use due to their primary cell construction whereas lithium ion batteries can be recharged to use many times and have secondary cell construction. What are the disadvantages of lithium-ion batteries? Lithium ion batteries have the potential to overheat and because of that aren’t as safe at higher temperatures. Can I replace a lead acid battery with lithium-ion? Yes, you are able to replace a lead acid battery with a lithium ion battery as long as you add an external charger. What is the difference between lithium ion batteries and lead acid batteries? The difference between lithium ion and lead acid batteries are the different materials they are made out of. While more expensive, lithium ion batteries are more efficient and have a higher capacity than lead acid batteries.
