Competing Against Lead Acid Batteries

Perhaps the easiest way to articulate exactly why many in the jan/san industry will eventually make a jump from lead acid to lithium ion is to compare the two batteries. Many of the factors battery manufacturers, and likely end users, hold dearest favor lithium ion, like the weight difference already mentioned.

The general consensus among battery manufacturers is that initial cost is the biggest con of lithium ion. In fact, the current cost could be so prohibitive for some end users that it would prevent them from even exploring the technology. A lithium ion battery producing the same amount of energy as its lead acid equivalent is currently several times more expensive, says Botting.

“I would still side with flooded (lead acid) because of the cost effectiveness,” says Wallace, whose employer has not made a jump to lithium ion.

If accepting the heavy cost of just the battery wasn’t enough, one must also factor in the floor machine it would be powering — autoscrubbers, for example, aren’t cheap. 

OEMs in the jan/san industry might be trying to figure out if the heavy cost works for them, says Tim Wittig, national sales manager at EnerSys, Reading, Pennsylvania.

What lithium lacks in upfront affordability, it gains back in cost of ownership. 

Flooded lead acid battery blocks typically have several hundred cycles in them and last about a year on average, says Wittig. Thin plate pure lead batteries have more life to them, with a warranty of three years and a life of about four to five years. By comparison, Wittig finds lithium iron phosphate and lithium nickel manganese cobalt oxide batteries both last thousands of cycles, with lithium ion in general having the capability of running up to six years. In fact, these batteries have such a long life span that they can outlive a floor scrubber, which Wittig finds to have a typical life of four to five years. 

Lithium ion batteries also best lead acid in that they offer more flexibility when it comes to charging. Lithium ion batteries take no issue with partial charging — users can plug and unplug the battery in as they please without fear of compromising its long-term operation. In fact, some users never or rarely charge their lithium ion battery fully.

“A lead acid battery that isn’t fully charged every time it’s used, but spends significant time stored at a partial state of charge, is going to have a short life due to accelerated sulfation,” says Botting.

While she cites a lot of pros to lithium ion batteries, Feodorov is particularly smitten with lithium ion’s partial state-of-charge tolerance as it relates to lead acid batteries.

“I can’t stress enough how much of a benefit this is with lithium over lead acid,” says Feodorov. “I’ve autopsied hundreds of lead acid batteries in my former jobs and under-charging or partial state of charge operation is clearly a huge cause of failure. Lithium has no issue with under-charging or never fully charging them.”

Disposal

While lithium ion batteries last longer than lead acid, they too, will reach a point of uselessness. The way both batteries are disposed of at the end of life vary considerably.

The lead from lead acid batteries can be melted and put into new batteries and can also be used for plumbing. Nearly every portion of a lead acid battery is recycled, says Wallace. Because of the value, recyclers will often pay end users for the battery they no longer need.

In comparison, lithium ion batteries are accepted at no cost or not accepted at all. In some instances, lithium battery owners will even have to pay to have them recycled.

Selecting either a lithium ion or lead acid battery is a decision that should be based on preference, needs and the situation in which an end user finds itself. Companies that value total cost of ownership, efficiency and timeliness might be fitted for lithium ion use. An end user who doesn’t want an up-front financial commitment might want to stick with the well-known lead acid battery.