E70 Battery Replacement - DIY

[haigha]

Originally Posted by ard

Buy a new spring and pop it in! 30 minutes. Waiting for the garage door man to show up and be there while he does the work is more time than the fix should take.

But people do get freaked out by the red warning label on it!

There's a good reason people should be careful when changing garage door springs. On my double, heavy wooden door, a lot of torque is required on the springs. If you use incorrect tools or you don't know how to position yourself when torquing each spring, you risk serious injury:

I used these instructions and got the parts from Amazon, including the correct bars:

How to Replace Garage Door Torsion Springs

It took some reading and probably over an hour of actual work. Disassembling and loosening the old springs took a considerable part of the time.

[Zoich]

Yay! Awesome! Yup there was only one store here in STL had the battery, tho i think they had more than one. Did you dispose your battery at Advanced Auto Parts to recover the $15 core charges? Should bring that total down another 15...

Originally Posted by rh71

so I wound up doing the Autocraft battery (manufactured by Johnson Controls like a lot of other batteries - I seem to have bought the very last one on all of Long Island says their website) and got it put in. Battery $148 + install & registration by a local indy $125 = $273. They also mentioned they had to reset the sunroof module as part of the process. Anyway, this was more a stay-away-from-the-dealer more than a DIY, but hey, still cheaper. Thanks for advice in this thread.

[alefcole]

thanks for info everyone

[rh71]

Originally Posted by Zoich

Yay! Awesome! Yup there was only one store here in STL had the battery, tho i think they had more than one. Did you dispose your battery at Advanced Auto Parts to recover the $15 core charges? Should bring that total down another 15...

yes thanks for the reminder - I did get that back the next day... still works great so far.

[3Series]

Any updates on the Autocraft battery?

The website says its 850cc, however the product picture shows 900cca. I guess I won't know until I pick up the battery and check the label.

This is my order and I'll pick it up locally.

AutoCraft Gold AGM Battery, Group Size H8, 850 CCA
Part No: H8-AGM

Warranty: 3 YR FREE REPLACEMENT


$181.99
Core Charges: $18.00
Discount: -$50.00
$149.99

[rh71]

^ no updates (which is a good thing)

[3Series]

The Autocraft Gold battery is labelled 900cc.

If you order online with a coupon, order the H8 AGM that says 850cc and verify it's 900cc when you pick it up.

[ard]

Originally Posted by basora

? I'm told that what I did was just reset the date and mileage, but the alternator current output is still at the appropriate level for the age of the battery ... Anyone?

Wait, what? How?

If regestering "just resets the mileage" and the output is still appropriate, then why would you EVER need to register???

Either registering does something that impacts how the battery is charged or it doesnt....

IMO

[ard]

shoot. sorry... OLD post, my bad. Mobile device.

[forum1]

Originally Posted by ard

Wait, what? How?

If regestering "just resets the mileage" and the output is still appropriate, then why would you EVER need to register???

Either registering does something that impacts how the battery is charged or it doesnt....

IMO

Exactly. From what I've read elsewhere it sounds like charging and usage profiles are tied into a complex hysteresis that starts with the car knowing when the battery is fresh. This plays a role in the energy management system shutting down various loads in order to preserve the battery for at least one engine start with some safety margin as the battery ages. But to what degree charging behavior is modified, and to the degree that it actually affects the life of a new battery being treated as an old one, well, it’s not clear to me it’s anything appreciable. It seems to me like a highly over engineered system.

And with the car being so smart about the battery state, you'd think they would include the battery as a Condition Based Service (CBS) item so the car would show the driver when the battery was due for replacement. The dealers would get more proactive battery sales, at least from the people that dutifully visit the dealer when the car tells them to. And assuming a nominal battery age of 4+ years, BMW would probably avoid having to replace most of the batteries under warranty. Of course the CBS items are also relatively easily reset by an end-user, and we wouldn't want that! Yet it's OK to reset the oil change, brake fluid, vehicle check, and other items via the instrument cluster’s service menu.

Also, I've heard that disconnecting the battery sometimes results in the car needing to be recoded due to various modules losing their coding, not just a window one-touch or steering wheel easy exit feature needing to be reactivated by the flick of a switch or two while standing on one’s head. Shouldn’t all of the module coding be in nonvolatile memory? Will simply disconnecting and reconnecting the battery result in any modules needing recoding by the dealer in order to function properly?

I’m about ready to replace my battery, so any clarity on this would be appreciated.