AGM VS Lithium-Ion Batteries: Which is Better for a Solar RV Battery Pack

What are the features of AGM batteries?

Higher efficiency than lead-acid batteries and cheaper than gel batteries.

For the same weight, AGM batteries provide twice as much power as lead-acid batteries and last longer than lead-acid batteries.

What are the features of lithium-ion batteries?

Lithium-ion batteries have the performance, safety, cost, reliability and other characteristics of offshore applications and RV generally, and are these applications' best combination.

What are the differences between an AGM battery and a Lithium-ion battery?

1. Life Cycle and Depth of Discharge

Compared with AGM batteries, the depth of discharge is limited, while lithium-ion batteries are not limited by the depth of discharge, so lithium-ion batteries have a longer cycle life.

2.Technology

The advantage of AGM is that it exists for a long time and the technology is relatively mature.

At low temperatures, AGMs perform better than Li-ion batteries. But impairment to the battery is inevitable. The battery's temperature needs to be adjusted if the lithium-ion battery wants to return to a normal state.

3.Dimensions and weight

Since AGM batteries contain lead-acid, they are heavier than Li-ion batteries. Because the lithium-ion battery takes up a small space, there is plenty of room to dissipate heat.

4.Maintenance

No maintenance is required as both Li-ion batteries and AGM are sealed.

What are the advantages of lithium-ion batteries over AGM batteries?

1. Lightweight

Compared with AGM, lithium-ion batteries weigh about a quarter of their weight.

2. Long cycle life

The cycle life of lithium-ion batteries is 6 times that of AGM batteries. In deep cycling example, the number of AGM is about 300 cycles, while the number Of lithium-ion batteries can reach over 2000 cycles.

3. High discharge capacity

AGM=50% capacity at 1C discharge

LiFePO4=100% capacity at 1C discharge

Lithium-ion batteries can provide more capacity at the same voltage. On the other hand, lithium ion can take advantage of size to expand runtime.

4. Low cost

The cost of the early lithium-ion battery is relatively high, but its cycle life is long, so the battery does not need to be replaced frequently. 

The AGM battery has a short cycle life and needs to be replaced within a certain period of time. So the cost will be higher and higher.

5. Higher charging efficiency

The AGM can be completely accused in 8 hours, whereas the lithium-ion battery can be fully charged in under 2 hours. Lithium-ion batteries are a fantastic option for those in a haste.

6. Low self-discharge rate

Under the same remaining power, the self-discharge rate of the lithium battery is not as fast as that of the AGM battery, so it can be stored for a longer time.

7. High safety factor

Lithium ion batteries' composition is lithium iron phosphate,lithium polymer and lithium ion.

It is the securest lithium ion battery since it does not generate heat and there is fire's no danger even though it is punctured.

8. Warranty

Lithium-ion batteries have a warranty period of up to 5 years generally, while other battery warranties are usually only one year.

Thus, while choosing between AGM battery and lithium battery, which is more desirable for solar RVs relies on your cost budget and use.

AGM batteries are tinnier upfront, but over time, more will be cost by them. Though lithium batteries' initial cost is high, it is more worry-free in the later step.