What you need to know about forklift battery technologies
In this article we compare forklift battery types by looking at power and energy, charging, maintenance, safety and more.
When it comes time to replace batteries for your electric forklifts and MEWPs, start by checking your owner’s manuals. Your equipment’s manufacturer will tell you what types of batteries you can use and how powerful the battery needs to be. Your vehicle’s size will dictate the power output needed. Forklift battery sizes range from 24 volt to 80 volt.
Once you know the power you need, you can consider the type of battery to use.
● Lead-acid batteries The most commonly used type. Lead plates act as electrodes suspended in a sulphuric acid solution.
● Lithium-ion (Li-ion) batteries More technologically advanced. Electrodes are made from lithium compounds.
Comparing battery types
Here’s what you need to know to choose the best batteries for your vehicle(s) and your situation.
1. Power and energy
First, some terminology. Energy density refers to the amount of energy a battery can hold. Power density indicates how quickly the energy in a battery can be delivered.
Lead-acid batteries have lower energy density but high power density so they can supply high current rapidly.
Li-ion batteries are good on both counts, delivering a lot of energy while taking up little space. This boosts runtime and performance.
2. Charging
Lead-acid batteries must be run down to 20% capacity before recharging to avoid shortening service life. Charging takes several hours (up to eight), and a cool-down period is required. Smart chargers can improve performance.
Li-ion batteries are opportunity charged meaning charging can happen at any time, like during a lunch break. Operators don’t have to run down the battery to guard against losing performance or shortening life. Opportunity charging can happen at designated stations throughout the facility.
3. Maintenance
Lead-acid batteries’ fluid levels need to be checked and topped up regularly with water. Automatic top-up systems are an option. Some facilities will need to maintain an inventory of back-up batteries to ensure uninterrupted operation. Back-ups can lose their charge when not in use and may have to be recharged every few months.
Li-ion batteries need little maintenance since they don’t need topping up with water. Connections, cables and wire may need repairs from time to time.
4. Safety
Lead-acid batteries can be the source of acid spills and hazardous fumes. Charging produces explosive gases, so you’ll need a separate, well-ventilated charging room. Because the charging cycle and after-charging cool down can stretch to 16 hours, operators may need to change batteries to keep working, increasing the risk of acid spills.
Li-ion batteries don’t present these problems since they are sealed against spills/ Also, since they can be opportunity charged, there’s less need for battery changes.
5. Life
Battery longevity is defined as the number of discharge and recharge cycles a unit can provide.
Lead-acid batteries generally last about 5 years.
Li-ion batteries last 5 to 10 years, depending on the application.
6. Recycling
Almost all materials in lead-acid batteries can be recycled.
Li-ion batteries are difficult to recycle.
7. Energy efficiency
Lead-acid batteries are less efficient, needing to be overcharged 10-20% for top performance.
Li-ion batteries are much more efficient with no overcharging required.
- Technology
Lead-acid batteries are definitely old-school with no bells and whistles
Li-ion batteries are more sophisticated. Every battery can connect to wifi or a cell network and transmit live data on state of charge, temperature, if plugs-ins were missed, etc. The Battery Management System built into each battery prevents overheating, overloading, excessive discharge, and other potential dangers.
- Total cost of ownership (TCO)
Lead-acid batteries are the lowest cost alternative when it comes to purchase price, although there are significant drawbacks such as maintenance requirements, safety, inefficiency, and the need for a charging room.
Li-ion batteries have a higher price tag (like maybe four times higher than lead- acid). However, these batteries are more energy efficient, pack more power into a smaller unit, are opportunity charged, are safer, and last longer. You may need to install charging stations. And if you want to convert from lead-acid to Li-ion, you’ll need a specialist to adapt the equipment. Keep in mind the difficulty of recycling.
Choosing the best battery
There are many variables to consider when selecting batteries. Here a summary:
|
Lead-Acid |
Lithium-ion |
---|---|---|
Power and energy |
Pack less energy than Li-ion but can delivery it quickly |
Pack lots of power into small package |
Charging |
Long cycle + cool down; separate charging room; must be drained to 20% |
Opportunity charged |
Maintenance |
Require monitoring of fluid levels |
Little or no maintenance |
Safety |
Require careful handling to prevent acid spills |
No major safety issues |
Life |
5 year on average |
5-10 years |
Recycling |
Yes |
Problematic |
Energy efficiency |
Inefficient, need overcharging |
Very efficient, no overcharging needed |
Technology |
Old school |
Sophisticated |
Total cost of ownership | Lowest price tag but have issues |
Higher price but worth it for many applications |
The good news - and the bad news - is that there’s no absolute right or wrong answer to the question of which battery is best. It depends on the needs of your facility and a myriad of related issues. Budget. Employee training. Space. Future plans. Luckily, you don’t need to face this decision alone.
For expert help with your next battery purchase, contact Morrison. Our trained forklift professionals are ready to serve you.
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