12v Battery Keeps Dying

I'm a little confused - can you explain exactly what was draining the battery in the end? I live in NJ, so I've been dealing with cold weather, too, but not below 30 degrees, and it's varied a lot in the past month. I'm on my 2nd new battery in 3 years, and it won't last a week parked outside. The last battery only lasted 1.5 years. I'd bought a new one after a winter when it would die frequently, and I lived in a city where I didn't have to drive much + it was getting old, so it seemed logical, although now I think something started going wrong then that would drain it.
Toyota only gives a 1-year warranty, so I was screwed for the $275 it cost me for that one. Had no choice but to spend it again for a new one about 2 months ago, and it's died twice since then. I have not been driving it much, admittedly, because I'm selling it and already have a different car. But I still think this is nuts! I don't want to sell it to someone as a lemon, so I'm bringing it back to the mechanic tomorrow, but it feels crazy to be funneling more time and money into it.
I'm not handy or good with mechanical things, and I'm a single parent with a full-time job, so I probably won't be tackling the problem myself. But I would like to understand what the issue may be. Thanks!

 

A lack of steady usage, sitting idle for mutliple days, for months, is really tough on batteries.

What's your parking situation; are you street parked, driveway, apartment block underground parking, or private garage. In short, where you're parked: would you be able to connect up a 12 volt smart charger, have access to 120 volt AC outlet, not create a tripping hazard, or have the charger stolen?

 

Thanks. I can park it in my backyard, where I can safely hook it up to anything and not worry about anything.

This just really surprised me, because the last battery only lasted 1.5 years and I drove the car almost daily, just about 10 miles. I've had the new one for a month, and yes I let it sit for a couple of weeks and it died, and then it sat for 1 week exactly, and it was dead. I did this because I'm selling the car, so I've been driving my Rav4 instead and didn't think that would be such a problem!
The mechanic has now checked out the current battery and doesn't see any problem.

Is there anything specific I should ask them to look at, you think? They still have it.

 

Maybe check what the milli amperage draw is, when the car off and dormant. Normal is around 20. If it's significantly higher, could be something is drawing current, depleting the battery faster than usual.

That said, it's normal for the battery to get run down, if the car's seeing limited use and only short trips. That's us, and I keep our 2010 connected to a smart charger pretty much 'round the clock. I'm using a CTEK 4.3, which has worked out well. I believe the current model, about the same spec's, is CTEK 5?

 

Well my classic 2001 has a problem with the key fob so i use the actual key to open and close the car right from the drivers door....
I believe the key was copied and what am using now is a not soo accurate copy because it can actually be removed from the car while the car is running
And it can be removed from the door even though its not back in the upright position

Which brings us to the kinda parasitic draw that happens occasionally when someone other than me tries to open my car and doesn't actively return the keylock into the upright position..

The car closes the window if u keep pressing the keylock towards locking the drivers door...

The car opens the window if u keep pressing the keylock towards opening the drivers door...

If the lock didnt go back to rhe upright position it will be stuck on either closing the window even though I closed it and went far from it.
So the car is off and the motor in charge of closing the window is drawing power from the battery and next day i see the battery is only 6 volts instead of 12.6 and doesn't start the car

So i would say make sure ur key is not ur problem cus ive seen the same problem with other gen1 around me.

Hope this can be useful