You have the right concept but just may have picked the wrong type of battery.
There are 2 types of batteries that are used in industrial applications for smaller walk behind/rider lifts
-industrial type encased single battery that utilizes several cells encased in a box (these are the common type battery used which can be lead acid or non-spillable maintenance free AGM type)
-also there are battery packs which consist of multiple battery's hooked in series or parallel together to create the voltage desired which in most cases is a 24v battery pack. Champion manufacture's these and are common in the pallet jacks and walk behind stacker units and other small lifts used today.

The latter uses deep cycle batteries which is what i assume you are trying to make here. Do not use standard automotive starting batteries, they are not designed for long duration power drain like the deep cycle batteries are. Most battery packs utilize group 31 batteries which is the standard size used in battery packs. They can be either lead acid or AGM. Exide makes a good group 31 battery that is good for these applications called an MC31 or XMC31, the MC31 is lead acid and the XMC31 is an AGM type.
If you want to know more about these you can google exide mc31 or go here and read up on them:
(remove the spaces from the link below and paste it in your browser url bar to go to the site)
ht tps :// w w w.deepcyclemarinebattery. com/reviews/exide-mc-31-and-xmc-31-megacycle-agm-200-sealed-maintenance-free-agm-marine-batteries. html

Note: there is a difference between these two when it comes to charging and the charger needs to be able to support the charging cycle as both do not charge the same way. Just make sure the charger you use supports charging AGM batteries if you decide to use those.