🅱Not had much experience with Li Ion batteries, must do some research on them... But 40 years off of a lead acid battery???? Come on, that's a fairy tale!!
My Tech College teachers would be rolling around on the floor over that one...
Batteries used in Solar set ups, telephone exchange batteries are known for 15 years lives, but they are not ordinary lead acid batteries, they have plates with other compounds added.
Typical car battery 3 to 5 years if well maintained and top of the line.
T5 in regular mining use, not recreation, but on a mine workers belt, one to two years max, with the odd one lasting 3 to 4 years, but they are VERY rare.
The secret to getting a lead acid battery to last, is never discharge below a certain capacity, I'll stick my neck out here, never below 80%. I use that figure as deep cycle batteries use that figure. NEVER, bash a lead acid battery, knocks the plate material off the stamped out plates and causes shorts in the bottom of the battery container.
Always keep the electrolyte level correct. NEVER over charge a lead acid battery, and finally, when not in use, keep it on trickle charge to prevent self discharge.

But 40 years off of a lead acid battery???? Come on, that's a fairy tale!!
My Tech College teachers would be rolling around on the floor over that one...

I had owned it about 10 years, bought SH from Caving Supplies, ex colliery. Age was estimated.
I remember it being used at Talybont on loan to a mate, we broke through in 2005 so I have accurate time fix there.
So when did they finish making them?
It would have to be at least as old as B – A
Fair enough, my 40 years was a guess, I was guessing 1960s

Typical car battery 3 to 5 years if well maintained and top of the line.

and while we are on, my Skoda is 8 years old and still on original battery, I have had it since about 2 years old.

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But 40 years off of a lead acid battery???? Come on, that's a fairy tale!!
My Tech College teachers would be rolling around on the floor over that one...

I had owned it about 10 years, bought SH from Caving Supplies, ex colliery. Age was estimated.

I pulled one out of the mud in Allenheads mine yard about 12 years ago. It still showed a charge on a multimeter.
Charged it up and it worked, only a couple of hours out of it but it did work.

Allenheads closed in 1981-ish? 20 odd years lying outside in the mud and still had a flicker of life in it

Still got it somewhere.

i bought my oldham battery from shiloh healthcare in 1990 when they were having a clearout, i sold it 2008 (still giving 8-9 hours) along with its oldham charger and my fathers battery that he got in 1980 (still giving 5-6 hours) i only used them 5 or 6 times a year but i can vouch for the older batteries with the screw cap fillers lasting a long time.
edit spelling blunders

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🅱Those stories of lead acid batteries would amaze any electrical engineer!! Two main problems with lead acid, paste on plates tends to fall off with age and short the cells out, and plates sulphate with time, ie, lead sulphate forms on the plates and sets as hard as glass forming an insulator.

Now NiFe batteries will last virtually for ever.

I've heard of car batteries lasting for ten years and sometimes longer, can't fathom that one out, as the battery is in a hostile environment, heat, cold and vibration.
I did have one car battery fail due to cell interconnection failure, the battery was still perfect beyond that. It had lead pins in holes that were shrunk together to form the "mechanical connection" One had somehow got loose. I opened the battery up to find out why it failed. I was surprised it started after my shift, got me to town, 50 miles, and then failed after I'd collected my paper and mail. It still gave the reference voltage for my alternator, so after I was started up by our local NRMA auto breakdown service, got me to the dealer for a new battery.

BUT, in all my years of working as a mining electrician, I never saw AN Oldham battery last more than four years in full service. We were lucky to see two years of good life out of them.

The first type "T"s, the red batteries with the clear filler gauge were a pita for leaking electrolyte from the clear filler/battery case joint. I don't think Oldham ever overcame that one. They then brought out the "smoke" coloured battery case with clear filler and I don't recall any leaks from that.

The first Oldhams had hard rubber cases with a rubber top cover that was "cemented" to the cases by the lampman. Never saw that type, a few years before I started in the industry. Next was the same battery with a metal top with the special locking screw and wax seal.

Those batteries had a large screw plug where you examined the electrolyte level and filled them from. I don't recall the model number.

The hard rubber looked and felt like plastic.

BUT, in all my years of working as a mining electrician, I never saw AN Oldham battery last more than four years in full service. We were lucky to see two years of good life out of them.

I think we may have the answer to our own question here.
There must be a world of difference between using once a week and eight hours on/eight hours off

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Is the longer life of car batteries possibly due to their duty cycle, they spend most of their life charged. The one in my wife's car lasted 12 years...

For a comparison, wouldn't electric vehicle batteries be a better comparison? How long did milk float batteries last for example?

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