The latest lithium battery technology is going to change the paradigm of storage solutions in the long run, as today people are using different types of lead acid batteries for storage, which are SMF, tubular, or gel-based tubular or SMF technologies, which have a litany of challenges and limitations.
The first limitation is cycle life as a lead acid battery cannot match the cycle life of a lithium battery. In literal terms, the lead acid battery life is defined by various parameters, one of which is the refilling of battery water, which is a big challenge for the user as they are not able to fill the water in time, and what kind of water they are supposed to fill is another challenge as they fill with any RO water or normal water, which destroys even the normal cycle life. The gel battery has the challenge of a higher temperature, so the performance goes down if the temperature is higher than a certain defined value.
Whereas lithium batteries, particularly LifePO4, are a very stable technology that has been proven for nearly two decades now, and the cycle life varies on the good BMS that regulates proper charging and discharging so that the battery has minimal heating inside, we can get anywhere between 1500 and 4000 cycles, whereas the lead acid battery cannot perform more than 400 to 500 cycles or so clear in terms of cycle life.
Another important factor is capacity at different discharge levels. As a result, lead acid batteries are typically designed at C20, which means that you can only discharge 5% of the battery before reaching the rated capacity. which is also not available as the process of making lead acid is very crude, and obtaining consistent power is a challenge. If you discharge the battery at 50% capacity, you will get 50% of its rated capacity. Whereas lithium is a C1 battery, so at any load, the capacity remains 100%. which is a very big difference when we use these batteries for storage purposes like inverters, UPS, and solar solutions. The lead-acid backup time can’t match the lithium battery pack.
Another major challenge is the cell balancing option available in the lithium battery pack in the BMS, which is one of the reasons that battery life can be achieved as a lead acid battery has six cells that cannot be balanced as there is no provision inside the battery. If we need to operate at higher DC voltages, we must balance the batteries, which the user does not do.
So if we need to put 120 V DC, then we need 10 lead acid batteries, which take up a lot of space, and they can’t be balanced with each other. The internal cells of each battery pack are also not possible, and the connecting wires take a longer route, which becomes another challenge as each battery takes up its own space, and we need to keep them at a distance, which creates wire losses. In contrast, lithium is a single pack that is one-fourth the size of a lead acid battery bank. So there are hardly any losses between the battery cells, which keeps minimum losses and cell balancing for each cell balanced through the BMS. So at the end, there is no comparison between lead acid batteries and lithium batteries. In the next 5 years, there will be a revolution in the industry, and lead acid will be out of business in the storage business.