Battery replacement
 

Hi all, really need your help here. My x's battery has been used for 4 years and the BMW Service in HK suggest that I should have it replaced. However, I feel fine with the old battery since it works really very well, no problem at all. So do I really need to replace the battery right now? If yes, is it can be done by myself? Could you please provide some instruction for replacing the battery. My X is 2001 MY 4.4i sports pachage. Thanks!

Standard BMW batteries last about 4 years MAX!!
It's an easy change out of the battery. The only difference is there's a vent tube in BMW's since the battery is in the back and not under the hood.
A good battery to use would be the Interstate unit that's suppose to be a direct replacement.
A better battery would be an Interstate/Optoma RedTop battery, but that would require some sort of mount to hold it in place since it's smaller, but totally sealed. Not sure if you can find either in Hong Kong.

Thank you, AUS! I think I can order an original BMW battery in HK for replacement. Could you tell me that where I can find the instruction of battery replacement?

If you could order an Interstate battery, you'd be better off. The stock batteries are expensive and not as good as the Interstate or RedTop battery. As for instructions, just loosen the mounting hardware, diconnect the terminals and pull it out. To install, just reverse the above. DON'T let anything touch both terminals at the same time. Don't forget to install the vent tube too. The battery's in the passenger side trunk, in the well. You may need to unscrew a few screws to remove trim piece. It's pretty basic.

what exactly size of the Interstate or Red Top battery ( can u give masurment? aprocsimate price ,and where to buy in CA -please??!?)
friendly
PS normally OEM bateries should work up to 7 years .

I must be a lucky one. I'm at original OEM battery, 7/01 build 3.0i (original owner). That make almost 5 years. Turns over like a charm without hesitation, even in winter.

My '01 is on the second replacement. Orginal OEM must have failed before I purchased as they had replaced it with a cheap non-OEM battery of the wrong size. Another thing CPO failed to discover. This failed 2 weeks after purchase and I had an aftermarket Exide fitted which came with vent etc. as required. It also has a 92 month pro-rated warranty.

01 with 93,000 Orig Battery. Minneapolis winters.

Battery Replacement
 

I got worried the other day about this and did some checking in the USA.

It appears that AutoZone has a model 49D that is made by Duralast for
65.99.

Way cheaper than the OE replacement from the dealer.

Piper51

You can get a RedTop at Costco for $100. There are Interstate Dealers ALL over the place. Just check for any shop and give them a call. It's not cost effective to mail order batteries since they're so heavy.