I bought one of these about 3 years ago. I had a dying battery in a van I was getting rid of but then I was not replacing the battery. I just kept this thing on it until the guy picked it up.

4 Modes Car Battery Charger, 24V/12V Battery Charger Automotive, 4A/8A LCD Battery Charger Switching Automatically from Fast Charging to Trickle Charging for AGM Lead-Acid Batteries https://a.co/d/3sj9Hts

This thing isn't available but there are many successors.

The battery in the SUV is at least 5 years old. It is a marine deep discharge battery as opposed to a typical car battery and this lady bought it because she was living out of this vehicle. Then it got to sit in my driveway for the last 3 years, being driven a total of about 100 mi, and nothing in the last year.

I had done multiple jumps and then drive around the neighborhood and let it run but that never allowed the battery to start the car the next day.

So I let this device run on it for a couple of hours and the vehicle started just fine and then I drove it around the neighborhood and then I let it sit for about 10 minutes.

It started fine on its own the next day. Wait 2 days. It started fine on its own again. Wait 3 days. It started fine on its own again.

So it seems this battery actually came back to life. Amazed.

I just got some gasoline stabilizer. I'm amazed the engine hasn't gummed up with this year old gas. Time to go fill it with a quarter tank and throw the stabilizer in.

I have two 5 gallon gasoline jugs that have been sitting there a year that have not had the stabilizer in it. Can I still use that gasoline? Do I have to dispose of it?