How long does a battery last?

2005 X5 3.0i

I'm meticulous about all the maintenance but while looking thru this forum, I just realized I've yet to changed the battery! I am the original owner and it has over 80K miles (highway majority). Should I look into replacing it right away?

On my '01, I swapped out the OE batt during year 5, and the 2nd replacement in year 10. And, I run a low amp Battery Tender on occasion, when it sits for weeks...
Your batt, if original, is up for an award!

I would change it out, in your driveway on your time, rather than trying for another month/half year, etc.

I rec'd a long, slow low amp charge before installation, as most batts sold have been sitting, and/or hot charged, which seldom gets that new batt up to full snuff, imo.
It is an easy <20 min DIY.
GL, mD

I'm expecting to have to replace sometime in the foreseeable future but the replacement Exide fitted in November of 2004 is still holding charge. The X does not drive every day, but as ong as I disconnect the V1 it fires right up.
Now Murphy's Law should kick in seeing how I just praised the beast.

BMWs original battery should last about 7 years, and a BMW battery will cost $455AU to replace, and a Bosch substitute about $275AU.

In the US the BMW OEM battery seems to last at best 2 years. Our 2001 is on the third battery. The BMW battery failed sometime before we bought it CPO and after sale I found a defective VW battery on-board. So much for the CPO pre-delivery inspection! That is when the current Exide was fitted.