The differences between Gel battery and Lithium battery

Many customers often have questions: why do I have to pay more for Lithium Battery than Gel Battery? Let’s clear all your doubts in one blog post.

1. Cycle Life

When you discharge a battery (use it to power your appliances), then charge it back up with your panels, that is referred to as one charge cycle. We measure the lifespan of batteries not in terms of years, but rather how many cycles they can handle before they expire. Cycle life is also a function of depth of discharge. Deeper discharges put more stress on the battery, which shortens its cycle life. Lithium battery have more cycle life than gel batteries and they generally last longer.

2. Depth Of Discharge

Discharge depth refers to how much overall capacity is used before recharging the battery. Gel battery should only be run to 50% depth of discharge. Beyond that point, you risk negatively affecting their lifespan.In contrast, lithium batteries can handle deep discharges of 80% or more. This essentially means they feature a higher usable capacity.

3. Efficiency

Lithium battery has a higher percentage of stored energy that can be utilized at 95 percent, compared to 80-85 percent on average for GEL counterparts. In the same example, you’d have over 950 watts of power available. Higher efficiency means your batteries charge faster. Depending on the configuration of your system, it could also mean you buying fewer solar panels, less battery capacity and a smaller backup generator.

4. Charge Rate

With higher efficiency also comes a faster rate of charge for lithium batteries. They can handle a higher amperage from the charger, which means they can be refilled much faster than gel battery. Moreover, gel batteries are limited in how much charge current they can handle, mainly because they will overheat if you charge them too quickly. In addition, the charge rate gets significantly slower as you approach full capacity. Gel battery can charge around C/5 during the bulk phase (up to 85% capacity). After that, the battery charger automatically slows down to top off the batteries. This means gel battery take longer to charge, in some cases more than 2x as long as Lithium battery.

5. Energy Density

The energy density of lithium battery is much higher than gel, meaning they fit more storage capacity into less space. For example, it may take two lithium batteries to power a 5 kW system, but you’d need 8 gel batteries to do the same job. If you are hanging the battery on the wall or hiding it in a closet, the improved energy density helps your lithium battery bank fit into tighter spaces.