I have Trojan AGMs that are well over 20 years old in my Golf Cart. They've had well over 2,000 charges and are still pushing nearly 90% capacity. No swelling,

I have Trojan AGMs that are well over 20 years old in my Golf Cart. They've had well over 2,000 charges and are still pushing nearly 90% capacity. No swelling, no leakage, nothing. My grandfather's old flood-chargeable lead-acid golf cart batteries were double that age, or more, and had an easy 10K deep cycles on them when he passed. That cart went two rounds of 18 holes, plus fishing at the water traps afterwards, daily. He would change the fluid in them monthly. Typical unsealed lead acid batteries can be maintained to last a long time. We used those to power an old warehouse with a solar array for a natural living commune in Memphis for over a decade. I can't tell you exactly how long they lasted as I had moved away from there while after that tenth year. Now once the plates have totally sulfated over, yes you aren't getting power unless you strip the sulfates away to reveal the plates again, but until then, acid refreshes work just fine, and you're looking at about 15 years before needing to replace the batteries due to sulfur coating if you only bother doing acid refreshes. You can get far longer if you know how to remove the sulfur off the lead plates. The days of sub-1000 cycle deep-cycle lead-acid batteries have long gone. All it takes is knowing how to maintain them. Nobody seems to do that any longer. Most of these were made with maintenance cycles in mind. (Not AGMs, obviously, they're totally-sealed.)