Lithium-ion showing signs of maturity

What is most striking about lithium-ion technology is that it has moved on from being just about small sized MHE such as pallet trucks. Many sceptical voices said the technology would never be robust enough for larger trucks when it emerged several years ago. Now many forklifts manufacturers have lithium-ion power options for counterbalance trucks.

This move shows not only what the technology is capable of, but is absolutely necessary according to Tobias Zierhut, head of product marketing at Linde.

"We need to offer a full range of trucks to persuade customers to shift from lead acid to lithium-ion. A customer would lose many of the benefits of lithium-ion if they still run some trucks on lead acid," he explains.

The big question for most customers is payback. Who wouldn't want to have to bother with charging areas and battery changes? The point is - 'when do I recoup my investment?'

Understandably, that very much depends, says Tobias, on an individual company's operations.

"If you have a one shift application, payback is difficult. Nevertheless, you have still the gains of no service, or wrong service of batteries, and lose the safety risk of battery exchange. For companies that have employees on sick leave due to battery change related accidents, it will be a clearer case.

"When you have a 2 or 3 shift application the payback - depending on the application, the working hours, hourly rates for employees - is 2-4 years.

"Lithium-ion has guaranteed 2500 cycles, which is double the lifetime of a lead acid battery. But after these 2500 cycles, the battery is still at 75% of the capacity, so you can easily have another 2500 cycles, so we talk about four battery lifetimes."

This is quite a profound shift in forklift use as the battery is highly likely to outlive the forklift. It will have a big impact on the residual value of the forklift if you buy, and on terms if you lease on contract hire.

Tobias explains: "We need a mind shift at the operation and logistics manager level - you are not leasing a truck with a battery, but you are leasing a battery with a truck. You need to think about how the battery will be re-used.

"When you talk about lease concepts - the lifetime of the battery is part of the lease deal - therefore the monthly cost of the battery can be cheaper than a lead acid battery today."

A further difference between lithium-ion and lead acid is performance transparency. With CAN communication, fleet managers will know exactly where the battery is in terms of its lifetime, making it easier to determine the residual value. A lead acid battery tends to be more of unknown quantity, it can be hard to establish how the battery has been treated, and therefore how much longer it will last.

Interestingly, the price of Linde lithium ion powered forklifts is not coming down. Tobias says: "Pricing is stable. We recognised the drop in price at the beginning would be  advantageous so pricing will not fall each year. We set the base, and due to the purchase power we have it will be hard for smaller competitors to follow this price point."

Switching to a new power source brings some slightly left of field challenges. 

One is short term hire. If you switch your fleet to lithium-ion machines, and need to hire a lot of kit for a seasonal peak, then you won't be able to hire lead acid trucks, as a major benefit of the switch is getting rid of the lead acid infrastructure.

Tobias says: "We will also have lithium-ion trucks in our STR fleets, so when customers request trucks at peak times, we can support them. By the way, renting is a good way for customers to test out lithium-ion trucks."

Another potential challenge is the sometimes conservative nature of the forklift operator. 

Tobias doesn't see this as a issue, but says that lithium ion infrastructure, while minimal compared to lead acid, does need to be sensibly placed.

"Lithium-ion will help the operator," says Tobias. "There are a lot of things he won't have to do anymore, he won't lose time looking for water, charging and changing the battery.

"For intermediate charging - that depends on the battery size you use. You can buy a big one and when its empty charge it, but I don't think this is the most clever way to use lithium-ion. The good thing is taking a smaller battery and using intermediate charging.

"Depending on the processes at a company, this is only thing the operator has to learn. It is clever to spread the chargers out to areas where operators have spare time - coffee machine, rest areas, dining areas etc."

To summarise, Tobias is on a mission to get fleet managers to test out lithium-ion technology and says many are surprised by how long a battery charge lasts, with some customers reporting 18 hours.

As forklift manufacturers are now likely to have ironed out many of the teething issue and are starting to fill out the truck ranges, it could be a good time to test the new technology out.