In a way...it was good that things worked against you...you ended up saving money.
Hopefully you hooked the battery up to the vent tube...its important that the battery is vented since it is enclosed...it will prevent excess corrosion as well as allow the hydrogen gases produced by the battery to be vented to the exterior instead of building up below the cargo floor, where a spark could ignite the gases and blow up the battery. And sparks can be generated as a normal occurrence while driving around when the charging system at times will overcharge and send a spark back to the battery.
As discussed in detail a few weeks ago...regardless of what your service provider told you...the e53 x5 does NOT have an IBS (intelligent battery sensor)...sensor nor system...so there is no way to code a replacement battery.
Those that are falling for this mixup with the e70 x5 is paying for something that is not needed. As you experienced yourself, as well as many others that aren't even aware that new BMWs require new batteries to be coded...swap in a new battery into the e53 without any issues at all.
click link to read reply with diagram/illustrations from a few weeks ago:
http://www.xoutpost.com/966037-post2.html
The e53 is a model generation BEFORE the e60 5 series. Its generational cousins are the e38/e39/e46. The e60 generational cousins are the e65/e70/e90...thus the IBS came along starting with their generation...which uses a different communication bus (MOST) and has iDrive etc and electronic dip sticks etc. THE E53 DOES NOT NEED BATTERY REGISTRATION!!!
