The cost of lithium and tubular batteries varies depending on the battery’s voltage, the Ah of the battery, and the efficiency of the Inverter/UPS used in the storage applications. So in this article, we have taken a very different approach to calculating the per watt price of the lithium-ion, and Tubular Lead acid baterries as the Tubular Lead Acid batteries can only be compared with the Lithium-ion batteries once their power is converted to the kWh level, both can be compared apple to apple. So let us take the case of a 12Volt 150 Ah Tubular Lead Acid battery of C20 capacity, which can be compared with Lithium-ion 12.8V 80 Ah battery of C1 capacity.
So, let us convert the Tubular battery into the KWh equation, which becomes 1.8 KWh capacity. The Lithium battery becomes 1 KWh, approximately 12.8, multiplied by 80 Ah, which becomes 1024 Wh or approximately 1 KWh capacity. The Tubular battery has a 1.8 kWh capacity, so how can we compare these two battery sizes? It is a big question.
So let us make it easy. The Tubular Lead acid battery of 12 volts and 150 Ah capacity has a C20 rating so that we can take out 5% of power from the rated capacity. This means if we take out 7.5 Amps from the 150 Ah battery we will get 20 hours of running power. But if we try to drive more power, then what will be the case needs to be seen to compare these two batteries.
Since lithium-ion is a C1 battery, the timing will remain the same if we discharge it with 7.5 or 80 Amps. The timings are easy to calculate, so if we discharge a lithium-ion battery with 80 Amps, we will get one hour of backup.
Taking 40 Amps from the Lithium-ion will give 2 hours of backup time, and so on.
But if we try to take 40 Amps from the Tubular battery, what kind of backup time will we get? If we try to take 80 Amps from the Tubular battery, what backup time will we get to compare the Apple to the Apple case study? People have used formulas without authentication for years to make users feel that the Tubular Lead acid battery gives a 3-hour backup on all loads.
So, we do the practical testing by taking one branded inverter from the market and checking both batteries with similar load conditions and backup time.
So, the standard being followed in the industry is a 400-watt bulb load, and resellers are aware of the result of 3 hours of backup. Beyond this, no one told them, so they think the Tubular Lead Acid battery gives 3 hours of backup at every load. So here we will test the backup time and make it in tabular form for your reference.
However, there are other factors where the comparison needs to be drawn:
- Lifespan: Lithium batteries typically have a 7-10 year lifespan, while tubular batteries typically have a 2-3 year lifespan. This means lithium batteries will save you money over time regarding replacement costs.
- Depth of discharge: Lithium batteries can be discharged much deeper than tubular batteries, so you can get more usable energy out of them. This can save you money on electricity bills, especially if you use your batteries for backup power during grid outages.
- Maintenance: Lithium batteries require no maintenance, while tubular lead-acid batteries require regular watering and cleaning. This can save you time and money. Also, the acid spills onto the floor once the battery water refills are done, which destroys the floor completely.
- Weight and size: Lithium batteries are much lighter and smaller than tubular batteries, saving you money on shipping and installation costs. Real estate costs are increasing daily, so having a smaller space is financially beneficial.
Lithium-ion batteries are a more expensive upfront investment than tubular lead Acid batteries. Still, they can save you money in the long run due to their longer lifespan, deeper depth of discharge, lower maintenance requirements, lighter weight, and smaller size.
Here is a table comparing the approximate cost per watt of lithium batteries and tubular batteries:
As you can see, lithium-ion batteries are typically higher in cost per watt if the load is less than 400 watts. But if the load is more than 500 Watts, then the cost of a tubular lead acid battery per watt is equal to a lithium battery or a little higher than the Lithium-ion battery.
However, as mentioned above, in any case, this difference in cost is offset by several factors that make lithium-ion batteries a more cost-effective choice in the long run, as the life of the lithium-ion battery is quite high.
Here are some additional factors to consider when choosing between lithium batteries and tubular batteries:
- Your application: If you are using your batteries for backup power during grid outages, lithium batteries are a better choice due to their longer lifespan and deeper depth of discharge. However, tubular batteries may be better if you use loads less than 400 watts.
- Your budget: If tight, tubular batteries may be a better choice. However, lithium batteries may be a better choice in the long run if you are willing to make a larger upfront investment.
Ultimately, the best way to decide which type of battery is right for you is to check the load used for your home or office in case you install your inverter/UPS.
