With regard to Lead-Acid vs Lithium Batteries, If you’re thinking of having solar with storage, you should familiarise yourself with the two main batteries that are normally paired with solar installations.
Battery storage is very common in places where they experience unreliable grid connectivity and require power continuity or reduction in energy bills.
The two main chemistry types are lithium-ion and lead acid.
Lead-Acid Batteries
How they work:
Lead-acid batteries are composed of lead plates and sulfuric acid. When the battery is discharged, the lead plates react with sulfuric acid to produce lead sulfate and water. When the battery is recharged, the lead sulfate and water are converted back into the lead and sulfuric acid.
Advantages of Lead–acid batteries.
They are :
- Reliable
- Cost-effective
- Easy to maintain.
Lithium Batteries
How do they work? :
Lithium batteries are composed of lithium metal and a non-aqueous electrolyte. When the battery discharges, the lithium metal will react with the electrolyte to produce lithium ions. When the battery is recharged, the lithium ions are converted back into lithium metal and the electrolyte.
Advantages of Lithium batteries:
They are:
- Reliable
- Higher Capacity.
- Higher Depth of Discharge.
- Higher Efficiency.
- Requires minimal maintenance and,
- They take up less space.
How do they compare? :
- Purchasing Cost
Lead acids are cost-effective compared to Lithium batteries. A Lithium battery setup will cost thousands of dollars more than a lead acid setup. It, therefore, depends on how much you, the customer, are willing to invest in your battery bank.
- Battery Capacity.
A battery’s capacity is defined as the total amount of electricity it can store. This parameter is measured in kWh. Lead acid and Lithium batteries come in all shapes and sizes depending on the manufacturer. So, we will look at energy density, wh/kg (watt–hour per kg). Lithium batteries are seen to store more electricity (wh) than lead acid batteries per kg. This translates to a high energy density for lithium batteries and the opposite for lead–acid batteries.
- Depth of Discharge (DoD).
Depth of Discharge may sound mind-boggling but let me break it down for you. Depth of Discharge is the energy that can be discharged (used) before charging again. So, for example, A 70 % DoD means that you can only use 70% of your battery’s total rated capacity and the Depth of Discharge affects the life cycle. So, the higher the DoD, the better.
- Lifespan
As we have discussed under Depth of Discharge, the lower the DoD, the fewer life cycles for the battery.
This means lithium batteries will have more life cycles than lead-acid batteries, which is a longer lifespan. Lithium batteries have a 15-year lifespan, while lead acid batteries have 8 years.
- Space taken.
Lead acid batteries are bulky. They are heavy and so, take up a lot of space. Lithium batteries are the opposite.
In Summary:
| Lead–acid batteries | Lithium batteries | |
| Purchasing cost | Cost-effective | Expensive |
| Capacity | Low energy density | High energy density |
| Depth of Discharge | 50% | 85% |
| Efficiency | 70% | 90% |
| Lifespan | 8 years | 15years |
| Space taken | Bulky takes a lot of space | Less space |
Conclusion
Lithium and lead acid batteries are competent if you need solar with a battery backup system. However, lithium batteries are so far the best option if you want higher efficiency, higher depth of discharge, longer lifespan, and higher capacity.
Lead acid batteries are more suitable for smaller solar backup solutions, such as residential properties, as they are the less expensive option.
Battery backup solutions are on the rise as most people are looking to save energy costs and ensure power continuity.
Would you like a FREE assessment of your solar needs? Contact us today at info@plexus-energy.co.ke or sales2@plexus-energy.co.ke
Grace Shiko Wachira
Technical Sales Engineer.
Plexus Energy Limited.
i want to purchase the following :
jinko solar panels 550w. 10pcs
growatt 5kw hybrid inverter. 1pc
hober 5.5kw hybrid inverter 1 pc
grundfos 4kw3phms4000 motor 1pc
200ah batteries. 4 pcs