These batteries will satisfy the most stringent requirements for power and dependability for sit-down 3- and 4-wheel lifts and dock stockers. They tend to be low in height (usually 22.5”) and quite heavy (usually 1800-5500 lbs) as they also serve as a counterbalance for the truck. JB BATTERY lithium-ion batteries just do the job and don’t require a lot of attention. 

https://www.lithiumbatterychina.com/lithium-ion-forklift-truck-battery/