i'm using a walmart battery that has a 2011 date on it in my charger.
starts just fine.
i used one of those pulse chargers to bring it back to life.
negative cable disconnected when parked. won't say how long this thing will last. just surprised it works.

I use both BatteryMINDers and CTEKs, and I think most or all of my car batteries are dry-cell types now. I just leave them plugged in.

i can kill any battery by neglecting it for too long. Haven't had much luck bringing them back, though, even with fancy Schumacher and Optima chargers.

When I need to jump start something I haul out the old Sears buzz box....

I use the CTEK MUS 4.3 POLAR battery charger/maintainer. Works great. .

https://smartercharger.ca/collections/car-battery-chargers/products/ctek-nus-4-3-polar

In my 5 vehicles I run Optima Red Tops in each, for the last 20 years typical life is about 8 years but I have gone as long as 12 years.
I did leave the interior lite ON by accident in one and the Optima ran down 10V tried to revive with my $125 Sears smart charger but no success.
Decided to try an Optima charger and the battery came right back up to normal..

Just my $0.02...

The over the counter Mopar battery was dying this summer. Its only been in the car since 2011. And it has had a tender on it whenever not being driven.


I broke down and bought a Autozone battery about 2 months back. Useing one of the ebay batter cap / decal kits . I like the look. And if it gets parked more than a few days. I have a NoCo tender on it.

Since trying to recover bad lead acid batteries since 1975
my guess is that a success is way less than 50%

The quote above about professional reclaimers being successful at getting 30% in a sellable condition sounds about right.

It is a more successful “investment” of time and money to treat a new & well made lead acid battery “right” and stretch its life out by 30% to 60%

This is even more true of Lithium ion batteries.

Elon Musk says that it is a rule of thumb that Tesla’s well made Li batteries still degrade by 6% per year.

On my 2016 Google Pixel XL by using the Accubattery App and not charging the 3450 ma-hr above 68% of original capacity,
and charging before it drops below 20%
the Accubattery App calculates that the “Linear Regression Trend Line” shows 2.6% decline per year and this old battery still has 75% of original capacity.
A 2600 ma-hr battery is still fine for the non gaming way I use a cell phone.

Same on 12V Milwaukee Tools Li batteries.
The original small 1.6 amp-hr batteries that came with my first tools are nearly shot
because I repeatedly charged them to 100% after uses
and let them sit there long storage periods,
but the expensive (!) 6.0 amp hour and 9.0 amp hour batteries that I let sit at 60% charge between uses
still are around 90%.

Battery Tool makers list price Li batteries like
Printer companies list price ink cartridges.

Musk has also said that it is a rough rule of thumb that 94% of the amp-hours it takes to recharge an old Li battery is an estimate of what the remaining discharge capacity is.