Are most loaders 24volt systems?

I am about to buy a wheeled battery charger for jumping dead batteries in our loaders this winter. We have 2 544j Deere loaders and one 928g z Cat, are these 24 volt systems or just 2 12volt batteries.

The charger I will get can charge or jump a 6/12/18/24 volt system but you will probably have to select which voltage to use.

Thanks