Choosing A Battery Bank: Lead-Acid or Lithium Iron Phosphate?

By Ameri Amp Dec 08, 21

A few years ago, lead-acid batteries were the go-to choice for van conversions due them being tried-and-tested. During those times, Lithium Iron Phosphate (LiFePo4 or LFP for short) was fairly new and people were hesitant about switching their lead-acid batteries for LFP batteries due to concerns about reliability and safety, as well as costs. However, LFP technology has advanced and it has been gaining popularity in recent years. Even Tesla is switching to LFP batteries for their standard-range electric vehicles!


That begs the question: should you choose lead-acid batteries or lithium iron phosphate batteries? We want to help you make the best choice, whether you’re looking for a battery bank for your van conversion, Recreational Vehicle (RV), home solar system, back-up power source, and etc., so we listed down some comparisons between lead-acid batteries and lithium iron phosphate batteries.


Let’s compare:

 

  1. Weight: A standard lead-acid battery weighs at around 67 lbs., while lithium iron phosphate batteries weigh around 27.5 lbs. That’s about a 1/3 of the weight of a lead-acid battery!
  2. Efficiency: Lead-acid batteries are highly inefficient for both charging and discharging. This inefficiency leads to a loss of about 15 amps while charging and a fast voltage drop during discharging which reduces the batteries’ capacity.
  3. Charging: LiFeP4 batteries reach 100% State of Charge (SOC) much faster than lead-acid batteries (absorption phase in an SLA occurs quite slowly). That means you get more power much faster.
  4. Discharging: Most lead-acid battery manufacturers do not recommend discharging past 50%, otherwise, the battery’s life will degrade much faster. That means that if you have a 100Ah lead acid battery, you actually only have 50Ah of usable capacity. Meanwhile, most LiFePo4 batteries can be discharged to almost 100%.
  5. Cycle life: Lead acid batteries achieve just 300 or so lifetime cycles, and after that, its battery life will be greatly reduced. On the other hand, LiFePo4 batteries can hit 3000-5000 cycles with minimal reduction to its life cycle.
  6. Voltage: Lead acid batteries’ voltage drops consistently throughout its discharge cycle while LiFePO4 batteries maintain their voltage throughout the entire discharge cycle.
  7. Cost: While the upfront cost of LiFePo4 batteries are much higher than lead acid batteries, if you factor in the performance and the battery’s longevity, the long-term savings of owning LiFePo4 batteries are tremendous. For full-time Vanlife (1 full cycle per day), for example, a lead acid battery will cost about $200 per year to operate and will last for 3 and a half years while a LiFePo4 battery will cost about $120 per year to operate and can last 8 to 10 years. Fewer replacements and labor cost, less down-time. That’s a lot of savings!
  8. Environmental impact: Lead acid batteries give off hazardous gas (hydrogen sulfide gas) during charging. This term is called off-gassing. Lead acid batteries can produce hydrogen sulfide gas when overcharging. The gas is colorless, poisonous, flammable, and the odor is similar to rotten eggs or natural gas; it is heavier than air and will accumulate at the bottom of a poorly ventilated space. LiFePo4 batteries are a much cleaner technology and safer for the environment.

Now, while some LiFePo4 batteries cannot charge in below freezing temperatures, they can be discharged. However, AmeriAmp offers a self-heating battery that can charge at -31°F (-35°C) and it even has Bluetooth® monitoring so you can check the State of Charge and Depth of Discharge of your AmeriAmp LiFePo4 battery through an app in your iPhone or Android device! How cool is that?


Here’s a helpful infographic to summarize the differences between lead-acid and LiFePo4 batteries:

If you’re still undecided on LFP, you can visit AmeriAmp’s FAQ page, or you can also talk to one of our representatives with any questions you have about Lithium Iron Phosphate batteries by emailing us at info@ameriamp.com and we will do our best to address your questions/concerns.


Ready to purchase a LiFePo4 battery? Browse our collection here.