Still has the original flooded cell batteries. They're old enough to vote and past due for registering for the draft. I wonder if they'll make legal drinking age? Probably be the death of them if they start ingesting beer or whiskey though. I've never cleaned the posts or added water or even bothered to check the level. About all I do is put a small auto charger on them before using in the spring and they keep on ticking. Cummins diesel pickup and D21 tractor both sport CAT batteries too. Really not that much more expensive than other batteries.
I did spring for three Optima yellow tops for my forklift though. Wane warned me when I bought the battery lift, that you really don't buy a battery lift -- you just kinda rent it when you figure battery replacement. Last winter, the lift reported a battery fault during it's POST. Drug the 3,000 pound AGM battery out of it, not really knowing what to expect. Had hoped that they used 12V batteries that were hooked parallel and series to come up with high amperage 36V. It wasn't the case though. I had one bad 2V cell about in the middle of the chain. New battery is about $6,000 with freight so that was kind of a last option. Seems that some places are putting a few regular batteries in, that have enough run time for occasional shop usage. Leaves a guy short of necessary ballast if you remove all of the old cells though. I ended up taking three cells out and leaving 15 in for weight. Then made up some short cables to hook three Optimas together and stuffed them in the space the old 2V cells were. Gives me about an hours run time & I bought an auto 36V charger to opportunity charge the battery when the lift gets below about 80% charge. We'll see how they last, but I can afford to replace them several times for what one of the OEM batteries would cost.