Lithium Ion Battery Cost Comparison

The answer is yes.

In order to compare the cost of a lead acid battery to that of a Li-ion battery, a number of parameters must be considered including:

  • What is the up-front price of the battery?
  • How deep is the discharge?
  • How many cycles does the battery last?

Of course the upfront price of a Li-ion battery pack exceeds that of a lead acid battery. Consider Dragonfly Energy’s 12V 100Ah LFP battery pack currently for sale for $999. The equivalent sealed lead acid deep cycle battery costs $180 and above.

First of all, the fact that lead acid batteries may only be discharged to one half of full capacity means that the actual price for the lead acid equivalent is $180 for 50 Ah.

Now consider the cycle life. A Dragonfly Energy LFP battery pack lasts at least 3000 cycles under deep cycling, for a lifetime energy storage of 3,000 x 100 Ah = 300,000 Ah. A lead acid battery realistically lasts 300 cycles under deep cycling, for a lifetime energy storage of 300 x 50 Ah = 15,000 Ah.

This brings us to the most important cost metric, the cost per Amp-hour of storage over the life of the battery:

Dragonfly Energy LFP pack: $999/300,000Ah = 0.33 cents/ Amp-hour

Lead Acid equivalent: $180/15,000Ah = 1.20 cents/Amp-hour

So, in reality, lead acid batteries are FOUR TIMES more expensive than Dragonfly Energy LFP batteries.

Now consider that Dragonfly Energy’s pack weighs 30 pounds. The lead acid equivalent weighs 75 pounds. There is no comparison!