5 years ago I created a series of how-to videos for a DIY solar generator. It was very successful and one of the most watched DIY solar generator videos on YouTube. It has also received a lot of requests for a Lithium battery based version. Today we show you how to easily upgrade that system’s battery bank to Lithium (LifePO4).

What are the advantages to Lithium Batteries?

There are several. First they can pack much more energy density in the same amount of space as well as significant weight savings. For example the Optima 12v lead cell / AGM battery with 55 amp hour capacity that we originally used in the build weighs 44 lbs. We are replacing it with a 12V LifePO4 battery of similar physical size, but it has a capacity of 100 amp hours, and only weighs 23 lbs!

Lithium batteries also can have much longer life. The one we are using today boasts a 10 year life span. Like all batteries though, the life can be shortened if it is over discharged or abused.

ECO-WORTHY 12V 100AH LiFePO4 3000+ Cycle Lithium Iron Phosphate fast charging Battery with BMS, Rechargeable battery for RV, Camping, Marine, Backup power, Solar Home Off-Grid System

• 10-year life & 3000+ cycle Eco-Worthys 100ah LiFePO4 battery contains 3000+ cycle times, each lithium battery can run for more than 10 years, which is equivalent to 3 lead-acid batteries.
• High Charging Speed Eco-Worthys 100ah LiFePO4 battery can reach 80% of power after one-hour charge, Under the same condition, the lead acid battery can only reach 20%. In the case of limited charging time, choosing a lithium battery can get enough energy faster.
• Lightweight & Easy Installation Eco-Worthys 100ah LiFePO4 battery is lighter than Lead-Acid battery with the same capacity. Our 100ah LiFePO4 battery weight is 22.93 lbs, only 1/3 of Lead-Acid battery. More convenient carrying, any mount directions, no leakage risk, safer usage.
• Capacity Expansion Eco-Worthys 100ah LiFePO4 battery can be connected in parallel and in series for larger capacity and voltage. Up to 4 identical batteries can be mounted as a series string as a 48V battery bank, and you can connect multiple batteries in parallel, while we suggest no more than 4pcs.
• Multiple applications Eco-Worthys 100ah LiFePO4 lithium battery is perfect for UPS backup, lighting, TV, e-Robot, loud speaker, coffeemaker, air conditioner, fridge, heater, e

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What is a BMS (Battery Management System)?

Many of the newer Lithium batteries comes with a built-in BMS system. This stands for Battery Management System and is built in circuitry to protect the battery from conditions that could shorten its life, or even pose fire / safety risks.

Because Lithium batteries have a higher energy density, they also have more requirements to keep the cells happy. They cannot be over charged like older technology batteries. In the past you needed to make sure everything connected to the battery was designed for lithium batteries, and would not overcharge it, over draw on current, run the battery too low, or it would risk damage to the battery or even increase the chance of a fire. The BMS system in newer batteries handles all that for us, so that they can now safely be used as a drop-in replacement in standard 12 volt systems.

Is a Lithium Solar Generator Better?

It terms of battery performance and portability, then yes, lithium batteries out perform the older technology used in lead acid based batteries. However there is a trade-off in cost. Lithium batteries still cost more than lead acid batteries, but the price difference is much less than it was ever a few years ago.

Do you need lithium batteries for solar power?

Whether you need to go with lithium battery technology for your solar generator is based on your needs. If you are building a large battery bank that does not need to be mobile, and you are not concerned about space or weight, you can still get more total amp hours per dollar with lead acid batteries. However when you factor in life expectancy of the batteries and other factors the argument for going with a lithium battery bank is getting stronger all the time.

How long does a lithium generator last?

Like most products, the useable life varies on a lot of factors. One of the biggest advantages to building your own solar generator is that can now easily replace any of the individual components when necessary. Solar panels are usually rated for a life of around 10 years. They can actually last longer, but the efficiency drops over time. A typical 10 year rated solar panel will be at or below 80 percent of its original efficiency after 10 years. Batteries are often rated in both years as well as charge cycles. However the total number of charge cycles will go down with deeper discharges of the battery. There are a lot of variables!