Help, don't know what it is !!!

[fjgregor]

Hi guys, new to the forum.

I recently got myself a 2009 135i. I've had it for about two or three months now. The previous owner really took care of the car and modded it to the point where I don't have to touch it.

Anyways, I was going to go to work this morning and it didn't start.
The control panel and the gauges were lit up as if normal, but I would press the button and it would try to start, then nothing.

So I got a booster, and I boosted the car using the terminal in the engine bay, turned it on, and let it run for a good 3-4 minutes.
Later on during the day, it's been vaguely turning on as if the exact same thing from the morning were to happen, but it ends up starting up a few seconds later after I pressed the button.

What could it be? Im in for service on monday to get the battery checked, I'm just worried it can be something else.

Thanks in advance

[E82.Love]

Our year 1 series had a recall a year or two ago on a battery recall. Could be that he never took it in for it.