Lithium vs. Lead Acid: Debunking the Top 3 Lithium Battery Myths

Posted September 24, 2021

The global lithium-ion battery market size is projected to expand by over 12 percent between 2021 and 2030, compared to the projected 5 percent growth in the global lead-acid battery market size during that same time period. Yet, despite the rapid adoption of lithium-ion batteries in both mobile and stationary applications, including in boats, RVs, golf carts, and homes, several myths surrounding lithium batteries remain. Whether you are deciding between different types of lithium batteries or between lead-acid vs lithium batteries, it can sometimes be difficult to differentiate fact from fiction. We have examined and debunked the top lithium battery myths below to simplify the decision-making process.

Myth #1: Lithium batteries are more expensive than lead-acid batteries

How much do lithium batteries cost? While it’s true that lithium batteries often have a higher upfront price point, they offer a much longer lifespan and far greater usable capacity than lead-acid batteries. A single lithium battery lasts 10 times longer than its lead-acid counterpart on average. The cost of lithium-ion batteries over time can be a lot cheaper than lead-acid. Measured by cycle life, or how many times a battery can be drained and then recharged before it needs to be replaced, lithium-ion batteries offer a 3,500 cycle life when discharged up to 80 percent. Flooded lead-acid and VRLA batteries, on the other hand, only offer around a 300 to 500 cycle life when discharged up to 80 percent. If you cycled your lithium battery once a day, it would offer more than 14 years of life, while a standard lead-acid battery often lasts less than two years.

Beyond cycle life, what most often fail to factor in is that you have to buy many more lead-acid batteries - sometimes double, triple, or quadruple as many - just to reach the same usable capacity as far fewer lithium batteries. This is because most only look at the total rated, or nameplate, capacity of a battery (i.e., the kWh the battery is theoretically able to store) rather than the usable capacity (i.e., the kWh the battery is able to store after factoring in depth of discharge, efficiency and charge/discharge rate restrictions). You can think of nameplate versus usable capacity like you would think of the salary stated in your employer’s offer letter versus actual take-home pay; In theory, your offer letter says you will earn $70,000, but with taxes, social security, healthcare, and other expenses removed, you are left with just $55,000 of usable income. Lead-acid batteries have a lower allowable depth of discharge, efficiency rates, and charge/discharge rates that directly impact the number of batteries you need to purchase up front, but also significantly impact the Levelized Cost of Storage or the overall cost per kWh you can obtain from a battery over the course of its lifetime.

RV Batteries in Cold Weather

Myth #2: Lithium batteries don’t work in cold weather

Whether you’re planning to use lithium batteries or lead-acid batteries, cold temperatures must be taken into account, as they can often cause irreparable damage to certain types of batteries. For example, with standard lead-acid batteries, the cold can seriously degrade the long-term performance and lifespan of the unit. Temperatures below the 32°F mark will noticeably reduce both efficiency and usable capacity of lead-acid batteries, providing just 70 to 80 percent of its rated capacity at 32°F.

Are lithium batteries good in cold weather? Lithium-ion batteries can operate with very little efficiency and capacity loss in cold temperatures, providing 95 to 98 percent of the battery’s capacity at 32°F. Even at 14°F, lithium batteries will provide 80 percent of their rated capacity. Typically, the more you pull from a lead-acid battery in cold temperatures, the weaker the performance will become. Unlike lead-acid batteries, lithium-ion batteries in cold weather will begin to warm when you use them, which will lower the battery's resistance and increase its voltage, allowing you to properly run your equipment.

Additionally, charging in cold weather calls for a different protocol and is crucial when you want to make your energy storage investment last. Nearly every battery - whether lead acid or lithium - requires a more involved charging process when the temperature begins to drop. Lead-acid batteries, however, have a tighter range of suitable charging conditions when compared to lithium batteries. Both lead-acid and lithium batteries need to be within their specified temperature ranges and must be charged at a slower than normal rate. For example, when charging lithium iron phosphate batteries (LiFePO4) in cold weather, specifically when temperatures are below 32°F, the charge current must be reduced to 0.1C, and when charging your LFP batteries below 14°F, the charge current must be reduced to 0.05C. Failure to do so can cause irreversible damage to your battery.

At RELiON, we have solved this inherent problem with charging lithium batteries in cold temperatures by developing and engineering a low-temperature LiFePO4 battery called the LT Series. The LT batteries have been rigorously designed and tested to specifically excel in cold weather environments, as they can safely charge at temperatures down to -20°C (-4°F) using a standard charger. The RELiON RB100-LT 12v 100Ah Deep Cycle Lithium Battery features proprietary technology that draws power from the charger itself, requiring no additional components. Once the battery is plugged into the regular lithium charger, the internal heating and monitoring system takes care of the rest. These batteries also feature a robust battery management system (BMS) that protects the batteries from irreparable damage in extremely cold temperatures.

Lithium Battery Power Supply On The Beach

Myth #3: All lithium batteries are inherently dangerous

You have seen the news stories about lithium batteries in hoverboards, laptops, cars, phones, and homes catching fire, but did you know that not all lithium batteries pose a fire risk? For starters, there are a number of different lithium battery chemistry types:

  • Lithium Iron Phosphate (LFP or LiFePO4)
  • Lithium Nickel Manganese Cobalt Oxide (NMC)
  • Lithium Cobalt Oxide (LCO)
  • Lithium Manganese Oxide (LMO)
  • Lithium Nickel Cobalt Aluminum Oxide (NCA)

Unlike lithium cobalt-based battery chemistries, LiFePO4 batteries generate very little heat. This is due to the fact that LiFePO4 batteries have extremely stable chemistry. LiFePO4 batteries also offer a superior chemical and mechanical structure that does not overheat to unsafe levels. This is because the charged and uncharged states of these batteries are physically similar and highly robust, which enables the ions to remain stable during the oxygen flux that occurs during charge cycles. Overall, the oxygen and the phosphorus atoms in LiFePO4 batteries are strongly linked by covalent bonding, unlike the weaker cobalt-oxide bond in cobalt-based lithium batteries like LCO, NMC, and NCA. As a result, when a LiFePO4 battery is overcharged or subjected to physical damage, the phosphate-oxide bond remains structurally stable, whereas the bonds in lithium cobalt-based batteries begin breaking down and releasing excessive heat, which eventually leads to thermal runaway.

Since they are inherently safer, LiFePO4 batteries therefore also do not require the additional components, and thereby costs, associated with the cooling and heat mitigation equipment that is needed for lithium cobalt-based batteries. LiFePO4 batteries are also incombustible, can withstand harsh conditions, and when they are subjected to hazardous events – such as collision or short-circuiting – they won’t explode. LiFePO4 batteries are a safe, non-toxic long-term solution and a worthwhile investment, which is why all RELiON lithium batteries only use the most advanced LiFePO4 chemistry.

To learn more about how to calculate your energy needs and find the optimal battery for your application and usage, visit our Lithium Battery Selector Tool.

The Bottom Line

From lifespan, depth of discharge, lithium battery cold weather charging, to battery safety, there are a number of factors to consider when it comes to determining the best battery to power your next adventure. Fortunately, you are now armed with some of the most important facts to help simplify your decision to convert to RELiON lithium batteries.

Contact our team of specialists to learn more about the benefits you can receive by converting to lithium batteries.