Which Battery Tender/Charger

[JCL]

Originally Posted by OlyS4

While I agree with your point, at the same time coming from an E53 X5, I see why the battery may not be able to keep up if not driven enough to provide a full charge, because it's staggering to me the increased amount of electrical goodies on a well equipped E70 from our previous '02 model.

Not sure if you've seen this but you may enjoy reading it.

http://www.bmwmotorsports.org/pdf/e7...Management.pdf

It isn't due to the loads IMO, but rather the complexity of the charging program. That link takes 35 pages to describe a system that replaces an AVR. If any of the sensors fail it defaults to a 14.3 v charge voltage. One should hope that a sensor fails, IMO

Even Joseph "Prince of Darkness" Lucas managed to produce functioning AVRs.

[buckeyewalt]

Originally Posted by JCL

Not sure if you've seen this but you may enjoy reading it.

http://www.bmwmotorsports.org/pdf/e7...Management.pdf

It isn't due to the loads IMO, but rather the complexity of the charging program. That link takes 35 pages to describe a system that replaces an AVR. If any of the sensors fail it defaults to a 14.3 v charge voltage. One should hope that a sensor fails, IMO

Even Joseph "Prince of Darkness" Lucas managed to produce functioning AVRs.

Ahhhh you hit a nerve when you said Lucas,,,,,don't forget to add Girling to the mix........

[bluetec]

Originally Posted by OlyS4

Thank you all for the feedback.

Do I need to determine if my battery is an AGM by looking at/checking it, or is it the only OEM battery in the '08 4.8l?

If original, your battery should be the white (lead-acid) type. Mine was lead-acid (mfg. Aug. '09) Remove the battery cover in the trunk with 4-5 phillips head screws. Write down the numbers and note the date of mfg. You can then Google your battery number for more info. If your original battery is black, then it is probably the AGM type.

[JCL]

Originally Posted by buckeyewalt

Ahhhh you hit a nerve when you said Lucas,,,,,don't forget to add Girling to the mix........

Hey, I owned a Morgan. With Lucas components. Pretty sure there were Girling brakes on it as well. It was character-building

[Penguin]

AGM or conventional?

Easy check. If it has a vent tube, it is conventional. If it does not have a vent tube, it is AGM.

[MRV99]

Take a look at this

http://www.xoutpost.com/bmw-sav-foru...ix-bmw-ag.html