What about a compromise, half wayish between lead acid and lithium. An AGM battery. Solid, no liquid. Can't leak. Can't evaporate meaning no maintenance.

Charge lasts a LOT longer when left sitting without charger. Also much more immune to discharge damage.

A planned time sitting unused, like winter storage, is much different from sitting bc you just don't know when you might drive it next.

Deliberate storage its easy to hookup charger as part of the process.

Not as easy if you squeeze in a drive here and there, and life gets in way. You think you'll drive it again soon, but that doesn't materialize. Or just having to disconnect charger to drive it, reconnect when you're done, means just one more, albeit tiny, hurdle to deciding to take the S for that errand or trip (that happens to include some fun roads), vs the daily, etc.

An AGM battery accommodates that usage pattern much more ably.

 

My neighbor gave me two new AGM batteries. One I hooked up for my alarm system as with frequent power failures (this is California) the battery can run the alarm for days.
The other I tried using as a fishing motor power source as the battery was a little lighter than the big Marine lead cell battery I normally use. I discovered this fall the 3 year old AGM will not hold a charge and goes dead.

Sometimes the simple solution is best.

 

How do we know that if they had been lead acid batteries and went through whatever these AGM went through they wouldn't have been even deaderer

 

Because the lead acid batteries are 10 years old and still kicking ass despite very heavy use and recharging. Same thing, different day.

 

My track S2000 tends to puke acid out of regular wet batteries due to the cornering loads. I usually get 3 years out of the Costco batteries.

I tickle charge the battery all winter.

If not for the puking, they'd last 5-8 years.

I might try AGM next time. But the cost to benefit may not make sense.

A lithium battery being super light is pretty cool. But damn are they pricey.

 

I mess around with radio control airplanes and they now use a lot of lithium batteries. They work great but there are a fair number of fires. All the guys that fly and use them are very smart and cautious. Transport them in secure fire proof containers. I use ammo cans with the gasket removed so with all the outgassing it won't turn into a bomb. We have dedicated spaces for charging and only do it when you are present. Lots of smoke and fire. A crash almost guarantees a fire in a few minutes time.
I have a subjective knee jerk negative reaction to a suggestion to use a lithium battery in my S2000.

 

I use BatteryMinder trickle/maintenance chargers but still experience battery failure. I take the battery off maintenance, the car starts fine, I drive for an hour or so, I park the car for an hour or two, and the battery is now dead. I have to pay as much for the tow as for a new battery, so I want a more permanent solution. I'm sure that the cheaper solution would be to just replace the battery every 3-4 years, but I'd really like a more sustainable solution. Maybe it's just a pipe-dream, but wouldn't LiFeP04 batteries last 10-15 years?

 

Check the voltage across the battery with the engine off and on. This sounds like an alternator issue.

 

This has happened multiple times? Or 1 time?
A regular battery should last 5+ years.

If its happened multiple times, any battery, including a fancy one, will die early

 

If it were alternator or any other charging issue slowly dying battery would start to show symptoms. Radio stops working, lights dim, engine starts stumbling.

I think its more likely its something draining battery. A constant draw.