Batteries are one of the most widely used devices in the world today. At present, lithium-ion batteries and lead-acid batteries are the two most used types of batteries, and well-known representatives for energy storage functions: LFP batteries and AGM batteries are famous for their energy storage performance. As two batteries with completely different materials and properties, the difference is undoubtedly very huge.
What's LFP battery and AGM battery?
LFP battery is lithium iron phosphate battery, also known as LiFePO4 battery, which is a lithium-ion battery using lithium iron phosphate as the positive electrode material and carbon as the negative electrode material. The nominal voltage is 3.2V, and it has no low performance. But the most reassuring thing is its safety performance, which is why many battery manufacturers are now chasing LFP batteries.
AGM battery is a valve-regulated sealed lead battery (VRLA battery) using a glass fiber separator (AGM). The positive and negative electrodes are composed of lead and lead oxides, and the electrolyte adopts sulfuric acid solution. The nominal voltage is 2.0V. Due to its long history, it is one of the most widely used batteries in the world.
What’s the Difference between an LFP battery and AGM battery?
LFP batteries belong to lithium-ion batteries, and AGM batteries belong to lead-acid batteries. Due to the huge differences in manufacturing materials and technologies, the differences in their actual use effects can be said to be very large.
- Weight and Volume
In general, the weight of LFP batteries may be less than half of that of AGM batteries; in the same way, LFP batteries are also smaller than AGM batteries. Under the same capacity, the difference in appearance and size of these two batteries can be said to be huge.
- Energy Density
The energy density of LFP batteries is generally 90~160Wh/kg, but high-quality batteries can reach 180~210Wh/kg. The energy density of AGM batteries is only 50~70Wh/kg, which means that LFP batteries can provide more energy while occupying fewer space resources.
- Available Capacity
The recommended DoD (Depth of Discharge) of LFP batteries is 80%, while the recommended DoD of AGM batteries is about 50%, which means that to get the same energy, AGM batteries may need to buy more.
- Serve Life and Cycle Time
Under the premise of normal use, the life of an LFP battery can reach more than 10 years and has 3000~7000 cycles; while the life of an AGM battery is 3-5 years, and the number of cycles is 1000~1200.
- Charge and Discharge Efficiency
The charging speed of the LFP battery is much faster than that of the AGM battery. Under the same capacity, the LFP battery may be fully charged in only 5 hours, while the AGM battery may be fully charged in more than 10 hours. The recommended discharge rate of LFP batteries is 1C, but supports higher-speed discharge, while the recommended discharge rate of AGM batteries is 0.5C. Excessive current may damage the battery.
Relatively speaking, LFP batteries are very high-temperature resistant lithium-ion batteries, but their performance at low temperatures is relatively poor and generally cannot be charged below 0°C; while AGM batteries have a wider applicable temperature range and can still be charged at low temperatures.
LFP batteries are extremely safe, due to their chemistry and manufacturing framework. Even if it is thrown from high altitude squeezed strongly, or even punctured, it will not explode. However, AGM batteries cannot do this, and since the internal electrolyte is sulfuric acid, there is a great danger in case of leakage.
- Environmentally Friendly
The materials used in LFP batteries are greener and have less impact on the environment. AGM batteries use lead, a toxic heavy metal. Regardless of the type of battery, if it is discarded at will, it will have a great impact on the environment.
- Self-Discharge Rate
The self-discharge rate of LFP batteries is around 2~3% per month, while the self-discharge rate of AGM batteries is around 4~6% per month (The remaining lead-acid batteries will likely reach 20%). The gap is still relatively large. When the battery is idle (for example, the battery is in winter), the LFP battery can be stored for a longer time without having to take it out for charging frequently. By the way, AGM batteries need to be stored at 100% SOC, while LFP batteries only need 50%.
There is no doubt that the price of the LFP battery is much higher than that of the AGM battery. If only the upfront cost is considered, the cost of LFP batteries can be more than 3 times that of AGM batteries. But if you consider the entire battery life cycle, such as more than 5 years of use, then the cost of LFP batteries will be lower and you can get a better experience.
Which is better?
Both batteries are excellent batteries and the choice of which battery really depends on your budget. If your budget is adequate, go LFP battery without a doubt, but if you are on a budget, AGM batteries are also a great option. But in general, LFP batteries are more recommended. Even if the upfront cost is higher, the overall performance, life, and safety are very good. What’s more, LFP batteries can replace almost any lead-acid battery, which is also a battery upgrade we often mention.