new battery

Hello, i have a 2005 120d and for personal reasons I haven't been able to use it for almost 2 years. Its parked in my garage and I think its time to pull it back together and start using it again. My 1st concern is the battery, it is obviously dead by now. My question is, do I really have to buy the original battery at the dealer (costs US$500) or can I just buy a simple equivalent battery with same specs (voltage/amperage)?

This is one of many questions Ill have and I know you guys will help me through this since last time I used my car it was under warranty so I had nothing to worry about, now Im on my own =(

Thx a lot

After market battery s $160 and works just fine... Google for compatible one

Tyvm, I just thought it had to be some special kind of battery designed for bmw, ill be getting a standard battery and let you guys know how it goes. Thx for helping

If you can find a way to register then you won't need to get a BMW battery.

Make sure the new battery has the same electrolyte as the old one (liquid instead of gel) and that it has the same amp-hour rating (Ah). After installing it, you'll need to have the battery management system reset.

Not sure about diesels but here in the us the gas engines don't need to have the battery registered. At least the 2005s

can drive around without battery registration till next service add extra 1/2 hour job