The difference of the Lithium

In 1859, the first rechargeable lead-acid battery was invented, which was made from a mixture of lead plates and sulfuric acid.

Lithium-ion batteries, on the other hand, are a relatively recent invention, having been available commercially since the 1980s.

Lithium technology has become well proven and understood for powering small electronics like laptops or cordless tools, and has become increasingly common in these applications, edging out the older NiCad (Nickel-Cadmium) rechargeable battery chemistry due to lithium’s many advantages.

1.Superior “Useable” Capacity

Unlike with lead acid batteries, it is considered practical to regularly use 90% or more of the rated capacity of a lithium battery bank, and occasionally more. Consider a 100 amp hour battery – if it was lead acid you would be wise to use just 30 to 50 amp hours of juice, but with lithium you could tap into 90 amp hours or even 100Ah (100% DoD).

2.Extended Cycle Life

Some manufacturers have shown through experiments that high-quality LiFePo4 batteries are expected to cycle tens of thousands of times. However, these theoretical values need further verification.From a practical point of view, and in real use, standard quality LiFePo4 batteries can deliver at least 2000 charge/discharge cycles at 80% DoD and 1C discharge rate, and the remaining capacity remains above 80%. These values mainly depend on the quality of the battery, but also on the charge rate and depth of discharge.

These cycle life results are much more better than NMC or NCA chemistries, massively used in electric vehicle industry. In contrast, even the best deep cycle lead acid batteries are typically only good for 500-1000 cycles.

3.Peukert losses and voltage dips are almost non-existent

Compared to lead-acid batteries, the discharge curve of a lithium battery is essentially flat，meaning that a 20% charged battery will deliver nearly the same output voltage as an 80% charged battery.

This prevents any issues caused by the “voltage sag” common to lead acid as they discharge, but does mean that any battery monitor or generator auto-start dependent upon voltage levels will likely not work well at all when monitoring a lithium bank.

The biggest advantage of lithium batteries is that the loss of Peukert basically does not exist. This means that Li-ion batteries can deliver their full rated capacity even at high currents. But in this case, lead-acid batteries can lose up to 40% of their capacity under high load.In practice, this means that lithium-ion battery packs are ideal for powering high-current loads such as air conditioners, microwave ovens, or induction hobs.

7.Climate Resistance

Lead acid batteries and lithium lose their capacity in cold environments. As you can see in the diagram below, Lithium-ion batteries are much more efficient at low temperatures. Moreover, the discharge rate affects the performance of lead acid batteries. At -20°C, a Lithium battery that delivers a 1C current (one times its capacity), can deliver more than 80% of its energy when the AGM battery will deliver 30% of its capacity.

Both lead-acid and lithium batteries lose capacity in cold conditions. As can be seen from the diagram below, lithium-ion batteries are more efficient at low temperatures. Besides, the performance of a lead-acid battery will be affected by the rate of discharge. At -20°C, a Lithium battery delivering a 1C current (one times its capacity) can deliver more than 80% of its energy, while an AGM battery will deliver 30% of its capacity.

In harsh environmental conditions such as heat and cold, lithium-ion technology is the first choice.

8.Easy to maintain

Lithium-ion batteries are almost maintenance-free. The battery management system automates the "balancing" process to ensure that all cells in the pack are charged equally. Just plug the lithium battery into the charger and you're ready to go.

9.Easy to place

Lithium-ion batteries do not require strict storage conditions and do not need to be stored upright or in ventilated battery compartments. You can also assemble Li-ion batteries into any shape you like. This is an advantage of lithium-ion batteries if you want to squeeze as much power as possible into a small compartment.

However, there was an incident of a defective laptop battery catching fire in the news many years ago - lithium-ion batteries are also known for battery fires.

The commonly used lithium ion battery formulation had been Lithium-Cobalt-Oxide (LiCoO2), and this battery chemistry is prone to thermal runaway if the battery is ever accidentally overcharged. This could lead to the battery setting itself on fire – and a lithium fire burns hot and fast.

That's one reason lithium isn't yet used to make large battery packs.

But in 1996 a new formula for mixing lithium ion batteries was developed – Lithium Iron Phosphate. Known as LiFePO4 or LFP, the energy density of lithium iron phosphate battery is relatively low, but it is non-flammable, so it is much safer than lithium cobalt oxide. Because of these characteristics of lithium iron phosphate batteries, it will have a wide range of applications in life.

4.Fast & Efficient Charging

Lithium-ion batteries can be charged to 100% capacity in a very short period of time. Unlike with lead acid, there is no need for an absorption phase to get the final 20% stored. And, if your charger is powerful enough, lithium batteries can also be charged insanely fast. If you can provide enough charging amps – you can actually fully charge a lithium ion battery just 30 minutes.But don’t worry if you can’t fully charge the lithium batteries to 100 percent. Unlike lead-acid batteries, failing to fully charge a Li-ion battery on a regular basis won’t damage it.

This give you lots of flexibility to tap into energy sources whenever you can get them without worrying about needing to do a full charge regularly. Even if there are several cloudy days, you don't have to worry about top off before the sun goes down, as long as you’re keeping on top of your needs. With lithium, you can charge as much as you can without worrying about the battery pack being undercharged.

5.Size and weight advantage

To highlight the unique characteristics of lithium-ion batteries in terms of weight and size, let's take an important example: lead-acid batteries vs lithium batteries.

6.Very Little Wasted Energy

Lithium-ion batteries store energy more efficiently than lead-acid batteries. Most lead-acid batteries charge at 85% efficiency, while lithium batteries approach 100% efficiency.

This is especially important when charging via solar, when you're trying to squeeze as much efficiency as possible out of each amp before the sun goes down or is covered by clouds.

Theoretically, with lithium nearly every drop of sun you’re able to collect goes into your batteries. With limited roof & storage space for panels, this become very important in optimizing every square inch of wattage you’re able to mount.

LITHIUM-ION BATTERY ADVANTAGES