A solar PCU (Power Conditioning Unit) is a device that converts DC solar energy into AC Electricity with the help of a battery, solar charge controller and Inverter. Solar energy is stored in the battery and used when the grid fails, or the battery is completely charged, and solar power is still available. This is a hybrid off-grid system where grid and solar sources are there in the system. So when the grid is available, the grid is bypassed to run the Load, and when the grid fails, the battery and solar run the Load. The battery is charged through solar. It can be used to power your home or business or to provide backup power during power outages. So far, lead acid batteries are used in the Solar PCU systems, which take a minimum of 12 to 15 hours to charge completely, which restricts the number of panels that can be installed with the Solar PCU system. The next challenge is the C rating of these batteries is either C20 or C10, which reduces the backup time in case higher loads are run on them. Another challenge user faces is the electricity bill, which is not reduced by these systems as solar power only charges the battery through solar power and sometimes when solar is not available or solar is much less than the battery is charged through the Grid power as well which increases the power bill of a user. Another challenge is the Lead Acid battery’s life, which lasts 2 to 3 years. The Tubular battery is used, which has a cycle life of 500 cycles if the user tops up the battery water properly in time.https://www.sciencedirect.com/science/article/abs/pii/S0378775309023441

Let us define the challenges faced by the Solar PCU installed with the Lead Acid batteries and how the Lithium battery solves these challenges:

  1. The solar panels with the solar PCU can be designed according to the size of the Lead Acid battery, so let us take the example of a 200 Ah battery in a 12 Volt solar system of a 1,000Watt solar PCU System. The battery of 200 Ah can take 10% of the charging only so that we can charge the Solar Lead Acid battery by 20 Amps maximum in the case of 200 Ah Lead Acid battery. So the solar panel sizing is restricted to 20 multiplied by 17 as the solar panel VOC is 17 Volts, so a maximum 340 Watt panel can be used for this system to charge the 200 Ah Lead Acid battery. Now, if we use a 100 Ah Lithium battery, we can charge this with 50% charging current, so we can charge this battery with 50Amps multiplied by 17, which is 850 watts of solar panels and which can charge the battery in 2 hours and can save a lot of electricity bill. In this case, we do not need to charge the battery to 100%, and we charge the battery to 25%, cut the grid and start using solar power to run the loads rather than charging the battery with solar power and wasting the solar power to charge the battery. Since the Lithium battery can be charged very fast rather than fully charging the lithium battery, we can charge it partially and then shift the Solar PCU to power the Load through the Solar power and Lithium battery, which will reduce the electricity bill substantially.
  2. The next point is the capacity or C rating of the Lead Acid battery, which is a C20 or C10 used in the Lead Acid battery, which reduces the backup time in case higher loads are used with these batteries. One can see this chart, which we have created using the Inverters available in the Indian market. 150 Ah tubular battery data is created on different loads, and the Load is bulbs used to test the capacity of a C20 of 150 Ah tubular Lead Acid battery.
150Ah 12V battery backup on different loads

150Ah 12V battery backup on different loads

One can see the battery capacity deteriorating fast with the increase in Load. Not only will the battery capacity deteriorate, but the life will also reduce if the higher loads are subjected to this C20 battery, as this battery is not designed to run heavy loads.


Backup time of 150Ah/12V Tubular battery

Backup time of 150Ah/12V Tubular battery & Lithium battery.

One can see the comparison of the Tubular Lead Acid battery with the lithium battery capacity required to run the different capacity loads. Since the lithium is a C1 battery, the capacity required to run the higher loads, we need the smaller capacity of the battery.

3. The size and the weight of the Tubular lead Acid battery vs lithium battery is another big advantage as the Tubular battery of 200 Ah is around 64 Kgs. In contrast, the 100 Ah battery, which is almost equivalent to the 200 Ah tubular lead Acid battery, will be less than 10 Kgs. and the size is also one-fourth of the tubular battery.

4. The life cycle of a Lithium battery compared to tubular lead Acid batteries the life cycle in tubular lead Acid battery will depend upon a lot of factors: the charging stages used in the Solar charge controller, the ATC technology used in the solar charge controller and the water topping of the Tubular battery done in time and the right kind of battery distilled water is used or not which is a very tedious process to follow. The Lithium battery has simple charging and no maintenance, which will run for more than 2,500 cycles and can last 4 to 5 times the life of a Tubular lead Acid battery in a Solar PCU if used properly.


Solar Hybrid PCU 1100 12V

Long lifespan: Lithium batteries have a lifespan of up to 10 years, much longer than lead-acid batteries. This means you will have to replace your batteries less often, saving you money in the long run.

No maintenance: Lithium batteries require no maintenance, making them more convenient than lead-acid batteries. You do not need to add water to them, and they are less susceptible to sulfation.

Environmentally friendly: Lithium batteries are more environmentally friendly than lead-acid batteries. The toxic Lead fumes are generated in the Tubular Lead Acid batteries, which harm the health of people around them. At the same time, a Lithium battery is a completely sealed battery and no emission of any gasses.

Overall, a solar PCU with a lithium battery is a good choice for homeowners and businesses who want to save money on their electricity bills, have a reliable backup power source, and reduce their environmental impact.

Here are some additional benefits of using a solar PCU with a lithium battery:

The Bluetooth and Wi-Fi feature is added and can monitor the solar PCU.https://suvastika.com/benefits-of-bluetooth-hybrid-solar-pcu

Mains fail

Mains fail

If you are considering installing a solar PCU system, I recommend keeping the points in mind that I have described in this article.