[kosmokratur]

Greetings, all

Carly is telling me my "battery" is on the way out. Testing with a multimeter shows that the issue is the H4, in the engine compartment.
My "local" dealer quoted me $273 for the battery. Seems a little steep but OK. Then they called me back and said that labor and "registering" would bring it up to $650. I think they're gouging just a little bit.
Has anyone done this job as a diy? It looks like I just have to take off the brace bar that covers half of the battery. Can't be too hard, right?
More worried about registering. I have several apps with a "register" function but they seem to be directly concerned with registering the MAIN batt, not the aux batt. Do I really need to pay the dealer ransom to register this little guy? Does the aux batt even need to be registered separately?
Local auto parts stores say an H5 fits the vehicle. I can get an AGM H5 for $175. Does anyone know whether an H5 even fits? I've read posts on F10 etc. forums where it can be made to fit by drilling holes etc. I really don't want to do that.
Wish I were in a position to just pay $650 and consider it pocket change, but it galls me. If anyone has dealt with this, I'd appreciate your input. Thanks!

[Qsilver7]

Check the negative terminal to see if it has an IBS (intelligent battery sensor). If it does, then it will need to be registered. If it doesn’t, then it is being monitored by either the PCU (power control unit) or some other module. There are various aux battery setups depending on model and options.

But registration is required when there’s an IBS on the negative terminal. Iin the illustration below…it shows the f15 X5 setup where the aux battery is controlled by the PCU…it doesn’t have an IBS so it doesn’t require registration like the main battery.

[kosmokratur]

specifically register such an aux batt? Or is it a dealer-only situation when that is needed?

[430Scud]

The Group 47/H5 AGM AUX battery in the engine compartment of the M550ix does not have an IBS fitting on the negative terminal (or on the positive terminal). I am told the IBS only isolates the AUX from the MAIN or "starting" battery. That is why if you wish to charge them, they must be charged separately, as they have no physical connection to each other.

I would assume, only the MAIN battery requires the registration.

I noticed most of the Group 47/H5 AGM sold by Interstate and AC Delco have white "Made in Germany" stickers on the top label. If you can find one of these, they are presumably made by Varta, the same supplier to BMW. I would not use a flooded battery on your G30. These came with AGM, so replace like for like.

The Interstate is sold at Costco for $183, but be aware Costco changed their warranty last year to three years "pro rated" which kinda stinks. It used to be three years free replacement. Not all stores have the German ones, but the USA made ones are probably fine. I have a USA made Interstate obtained from Costco in my Ferrari for the past couple years and working fine.

[kosmokratur]

Looks like I just have traditional battery cables, no sensors.

Does anybody know what size those star-shaped fasteners might be?

[ezaircon4jc]

Originally Posted by kosmokratur

Looks like I just have traditional battery cables, no sensors.

Does anybody know what size those star-shaped fasteners might be?

External Torx.

[430Scud]

Originally Posted by kosmokratur

Looks like I just have traditional battery cables, no sensors.

Does anybody know what size those star-shaped fasteners might be?

Get a set of them, I got a set of sockets in 3/8" from a Harbor Freight store or Amazon, I forget where, wasn't expensive.

[kosmokratur]

I bought a set of sockets, up to size 24, from Bezos for about $15. Today, I bought a dealer battery for $250 - I was there anyway, and it seemed like the best deal I was going to find. It is now on the CTEK but it was made this month. Parts guy confirmed that they don't bring over the Varta batteries (but maybe Costco does). Wouldn't mind the extra capacity of an H% but didn't want to fool around with making it fit in sub-freezing weather, even to save a few bucks. My teen has the week off from school, so I'll make it a small father-daughter project to replace it.

[kosmokratur]

Does anyone happen to know the torque settings for those bolts that hold down the aluminum stiffener shown in my pictures, or is it just "tighten until tight?"

[Popell996]

Originally Posted by kosmokratur

Does anyone happen to know the torque settings for those bolts that hold down the aluminum stiffener shown in my pictures, or is it just "tighten until tight?"

PFT, rather than VFT…

[vinniea]

Hi Kosmokratur, I also need to replace the front battery and I was wondering if you were able to get it out by just removing the 2 Torx screws holding the aluminum stiffener bar that is on the way or are there more holding the bar under the plastic that covers the other end.
Thanks for the feedback
Vinnie

[kosmokratur]

There are at least 8 screws (4 on each side), plus both wipers have to come off - probably the little electronics box, too.. I found a local shop that would replace it for me for a reasonable fee (not the $300 requested by the dealer) and they'll be doing it later this week.

[vinniea]

Ah! OK that a good way to go. I found someone who did it and listed the steps below, I’ve also added the illustration for future references. Seems that removing the wiper arms is the most difficult step but I agree is too much for a battery replacement.

“PITA to remove the wiper arms, windshield cowl, chassis member, cables, etc to replace battery. Illustration to remove cowl panel is very helpful
Suggest prelube cowl insert (at windshield glass) with soapy water, brushed in, then pry from below, don't pull
I used painters tape to mark positions of wipers on windshield before popping tapers with an old Snap On puller
Ditto tape and marker to register cowl position on glass before removing
Also marked position of chassis member on shock towers before removing. Those fasteners; two each side, need a tip sealer going back in - low strength thread locker works fine
I used a BMW battery, 60 AH, from the dealer parts dept. About $230”

[kosmokratur]

Thanks for posting that.