Car doesn't start, trickle charger? Battery type?

[Jarkarp]

I have a 2012 135i, and I have not been driving it much since the pandemic started. The last time I drove it was probably 4 weeks ago on a 2-mile trip. Anyway, when I tried to start it today, all the indicator lights, radio, and climate control come on okay, I could hear what sounded like starter noise, but the car wouldn't start.

I am wondering if the battery charge is low and if a trickle charger can help bring the battery back? I don't want to jump start the car since when I did it once a few years ago, the "window auto-down/up-when-opening/closing-door" feature stopped working and it was super annoying. It took updating the software for $200 to fix it.

There is an "official" BMW charger but it's pretty expensive at about $150, there are various chargers in the $60-$100 range on Amazon that seem to get good reviews. Any recommendations?

I looked at my battery and its part number is 61 21 2 353 808. Is this regular battery or AGM? The reason that I am asking is that there are trickle chargers with 2 different settings for regular vs. AGM batteries and I wanted to make sure I use the right setting.