There are many people thinking about switching their lead acid mobility scooter or power chair batteries to lithium. They may be hearing through different channels about all the benefits that this newer technology can bring; and although the pros seem to outweigh the cons on face value, there are some factors for consideration.
The Valen technical team has spent many years working with our mobility scooter partners and have put the following together, with the understanding of the emergence of this new technology in the existing market.
What are the benefits?
First and foremost, lithium batteries have an incredible cycle life. These batteries can achieve up to 4000 cycles to 80% Depth-of-Discharge. Compare that to an equivalent gel battery which can achieve up to 300 cycles at the same depth, and you are talking about a battery that will outlast your scooter.
High energy density
It’s what’s inside that counts. Lithium battery technology can pack more power into a smaller footprint. For example, the Valen ENLiFEN lithium batteries have been used to replace a 40Ah lead acid battery with 60Ah of power; that’s an extra 50% capacity.
Lithium Batteries are rated at C1; i.e the power is discharged over 1 hour. VRLA rated at C10, which indicates the power is discharged over 10 hours. Basically, this means that there is greater power from lithium. These batteries will deliver consistent battery performance over varying terrains.
Lithium batteries are lighter. Less weight = less drag on battery and better run-time for your scooter
Better Battery Life
The battery management system (BMS) in lithium batteries prevents over-discharge. Lead acid batteries to not have a BMS. The BMS protects the battery and extends battery life.
What should be considered?
All that sounds great, right? Well, there are some important considerations for customers thinking of switching to lithium batteries for their scooters. It’s not a suitable option for all users, so the following should be weighed up to make informed decisions.
Lithium batteries are considerably lighter than lead acid batteries. Some can even be a third of the weight as an equivalent. Although this can lead to better run-time, it can wreak havoc with power chair users. Power chairs rely on the weight of the lead acid battery to provide a lower centre of gravity for the chair. Removing VRLA battery weight from power chairs will impact this and could lead to tip-overs.
Lithium batteries do not come cheap. They can be around four times the price of the equivalent gels.
Add to the cost of the new batteries, the user will need to add the cost of a new charger. Lead acid battery chargers cannot be used to charge lithium batteries, and vice versa.
When installing the new batteries to a scooter, the technician needs to be aware of the scooter’s specifications. Some scooters can house batteries wired in series, some cannot. In addition, we recommend checking the specific connections on your model of scooter are suitable for your battery. Some scooters are wired for 24V and some for 12V.
Battery Level Indication
Some models of scooter are not compatible to read the state of charge of lithium batteries. What this means for users is that the battery level indicator will show full state of charge until the battery is flat, then will show no charge. Users must be aware of the state of charge for their battery and cannot rely on the battery level indicator on their scooter.
Important for consideration, users need to ensure the discharge currents from the scooter motor do not exceed that of the BMS rating on the lithium battery. Check with an appropriate mobility scooter retailer before selecting new batteries.
Lithium battery technology is emerging and provides many benefits. At this stage, retailers are fielding enquiries about retrofitting this technology to existing mobility vehicles. While there are many benefits, it is important that certain factors are considered. The Valen team hope that this has helped shed further light on these factors.
Reach out to the Valen team today to discuss this or any of our products in more detail.