I know all too well the PAIN of buying batteries for these dinosaurs. One time I bought them at NAPA, they lasted about 18 months and told me there was no warranty!! I've almost never trickle charged them over a length of time because I always start the machine at least once a month and use it, even in the cold, otherwise I'd trickle charge them. I wasn't too happy about the NAPA ordeal, could not make sense of it, although they tend to have better products than these typical auto parts stores. When they wouldn't help me I went straight to John Deere and paid 600$ for 2 new 6V batteries wired in series for 12V, I think that was about 7 years ago or so now and they still work fine. I just make an effort to constantly start and run the BHL, in your case you'll have to trickle charge them if you don't use the machine often enough. I later learned you can possibly use a welder to de-sulfate the plates on an old battery, I wish I had tried that before I brought those old ones back to NAPA because that was a big loss... I bet that thing will start up and run perfect, just change the fuel filter first, use fresh diesel, and it wouldn't hurt to change the engine oil and HYD filters. You may have to knock out some pins to get grease in them again (or a torch on the area works sometimes), but you don't have as many as a typical BHL does. If you need any help I'll be happy to pick up a hazmat suit and dive under/in there with ya. Have fun in PA! This summer was awesome up until a week ago, not fun ATM...
All our government does is distract us while they steal from us, misspend our tax $ and ruin our country