Less than 1 year old 2020 Crosstrek with < 7k miles as I don't drive it often.  I have jumped the battery at least 4 times because if I don't drive my car every week it drains.  I took it into the shop and they said it is normal you have to drive your car weekly.  So that means I cannot go on vacation more than 1 week or leave my car at the air port longer than a week otherwise I would have to get it jumped.   Does that sound normal to you all?  Is it true that if you dont drive your brand new car at least every week it will die because it has a parasitic leak?   Sounds crazy that I will have to either have someone come and start my car every week or have a jumper company on my speed dial so I can call them when I get off the plane and ask they have my car jumped before I get to it.   OMG!  I would not recommend this car during a pandemic, people that work at home or the older generations that don't drive it every week.

Any ideas on what I can do?

We don’t know the history of the vehicle and batteries are *routinely* problematic. 
 

1. test for a drain in the vehicle. It’s a simple test. 

2.  have the battery tested at any major national chain like advanced auto parts, etc. 

more than likely the battery is weak and the first time it ran low degraded it and it’s now junk. 

again we don’t know the history or how likely options 1 and 2 are   

Get a better battery and never think about it again. Get something with more power then the stock unit. Get an Odyssey if you want the best, call them and ask which one.

The battery might be bad or the first time it died degraded its capabilities. They are *not* forgiving.

Youre over thinking it. More than likely the first time it ran low was more than a week - and was preceded and/or proceeded by short trips where the battery wasn’t fully charged.

Batteries degrade every time they run low - so you’re making it worse every time it does this.

You could check for a drain and/or have the battery tested.

The fuel pump runs every couple of hours to keep pressure in the system.  That is what is killing your battery.  Just disconnect the battery if you think you won't be driving it for a few weeks.

Edited January 21, 20215 yr by ezapar

Sorry I'm late to the party... 

You actually have a few good options. I had the same issue, but part of it was that my OEM battery was three years old. The dealership said my aftermarket stereo was to blame, but I seriously doubt that. They said the stereo was also why all of my door lock actuators eventually failed, which is clearly stupid. 

1. You can get a deep cycle battery, such as the Optima Gel (ideally larger than is suggested for the vehicle).

2. You can find out what is draining the battery, but this is often an exercise in futility. 

3. You can add a second battery (either serial or parallel), but it is not likely to fit in the engine compartment. 

4. You can keep the car on a trickle charger or battery tender. 

I went with an Optima Yellow Top one size up from the standard for a Crosstrek... love it! In retrospect, I might have gone with an even larger battery (such as an Odyssey), but I'm not disappointed with the Gel. 

Edited October 24, 20214 yr by IONurse

Buy portable jump starter. Is it some external electronic in car?