Get a NOCO battery charger maintainer, The 5 amp one will make a battery like new in about 3 or 4 days. You just cycle through your machines and you always have good batteries.
That is a great looking backhoe, you appear to have lots of good equipment available in your part of the world. The Ford 3000 looks in great condition and I wondered why you did not fit the backhoe to the tractor with the FEL as the FEL would have balanced the weight of the backhoe and stabilsed the tractor when using it
Thanks there is a lot of equipment out there how good it is is always a spin of the wheel. We put it on the 3000 because it had hydraulic output already the 3600 does not at the back and dad normally had a plow/grader blade equip to it for when it snows and it's the main work horse at the moment and the 3000 just sits alot so this makes it more useful in the long run as a dual propose mower and backhoe.