Battery issues

[mollyshark]

Finally happened. Got in the Z to start it one nice day this week and dead as a doornail. Even my charger won't do it. Got a slight flicker on the door lights and blech. I know there has been discussion on batteries here. Can someone point me to where that is or give me a couple quick recommends? I don't track, so I don't care if it weights 1.308546 ounces more! ;)

Monica

[macfly]

If you have no interest in changing to a different unit then I'd just get a new one from your local BMW dealer, or if there isn't a good one near by then buy a trusted brand name replacement from Sears. To find the previous threads on batts the easiest thing to do is use the Search function in the very top blue bar above.

[Z8Mania]

Agree. I jumped my car, drove down to the dealer, and left half an hour later with a new battery installed. As preventative maintenance, I am going to replace the battery every 4-5 years now.

[mollyshark]

Will do. Duh, search never entered my mind. Of course at that time of the morning I miss a lot. Will see if I can get it jumped, bundle up, and take it for a new one. Thanks.

[bobby]

Hi everyone,
Can someone help, as our Z8 battery is completely dead and we can't open the trunk. We had someone come to replace the battery but that no luck opening the trunk even with the switch inside as I guess that too needs battery power.

Thanks

[macfly]

You can jump start in using the + terminal point and any 'ground' under the hood. (the + terminal looks like the oil filler cap's twin) or if the car is inside, and you can wait a moment, I'd suggest plugging a trickle charger into the cigarette lighter socket in the center console, and give it an overnight charge. The Z8 is a battery eater, they usually die in a few weeks if not kept on a trickle charge, and even when trickled you'll be lucky to see more that three winters on one battery.

The entire manual is over in the PDF section of the site incase you need it, but here are two relevant pages.

[Grease Monkey]

Another option is to use the manual release for the trunk lid since it does not require power to operate. Flip the backrest of the passenger's seat forward (pull the horizontal strap at the outer edge of the backrest to release) and use your key to open the storage compartment located on the floor behind the seat. Inside you will see a fuse box cover. Remove the cover and you will see 2 pull rings. The one towards the back of the car unlocks the trunk lid manually. Just pull it. Hope this helps!

[macfly]

Funny thing is I actually posted that from the manual, and then I was worried that it only referred to the little center console storage space, so swapped it out - must be a premature senior moment!! :rotflmao:

[bobby]

Hi ,
You guys are the best. I was able to jump start. As the battery is more a less completely dead is it safe to replace it with a new Optima- Red Top with 720 CCA or I should I to BMW dealer for a new one.

Thanks again

Bobby

[macfly]

I'm not sure - I don't know if all batteries are created equal, but if it has the same fitment code, size, shape, amperage etc then I'd guess it should do?

[KenZ8]

I've just replaced a Duralast battery in my M/B which had more cranking power than the OE at half the price (I guess made in Mexico is cheaper than made in Germany!). The first Duralast lasted 5 years. There was an interesting step that had to be taken in the swap- the key had to be in the ignition in position "0" when the power was disconnected or else the computer would erase access for all of the keys and their ability to start or remotely enter the car. Does the Z8 have any such requirement?

[macfly]

Good question - again I don't know for sure, but it is definitely worth checking on before doing!

[Grease Monkey]

It is important to use a vented replacement battery in your Z8 and hook up the vent tube.

[redz8]

There was an interesting step that had to be taken in the swap- the key had to be in the ignition in position "0" when the power was disconnected or else the computer would erase access for all of the keys and their ability to start or remotely enter the car. Does the Z8 have any such requirement?


I left the battery charger plugged in as I replaced the battery and that seemed to avoid all the key/memory problems.

[Z8Mania]

seems like a prudent step!

[KenZ8]

My battery "up and died" with no warning whatsoever. Never sitting more than 2 weeks at a time, and always with the battery tender, the battery failed suddenly and completely. The car started with great enthusiasm, and we left for our adventure of the day. The next attempt to start her (now 100 miles from home) was horrifying, as it would not even recognize the chip in the key, leaving the ignition locked and all switches, including the trunk, dead. Because of earlier posts, I knew exactly how to get a successful jump start without looking at the manual, which was in the inaccessible trunk.
I second the motion to replace the battery, even if it seems fine, after 4-5 years. I even wrote the date on the battery since it never seems that long.
A great big thankyou to all who have posted this and other problems along with the solutions for the rest of us to file away in the recesses of our brains. Somehow I can remember the details of every post, yet I always seem to forget at least one item at the grocery store.:o

[Z8Mania]

This is exactly what happened in my case but it happened at my house which made it much easier to digest. Glad you got home safe and sound Ken!

[Z8 Steve]

I had a dead battery just this morning. Successfully started with a portable emergency starter, and drove it to the BMW dealer for service (I was planning to bring it there anyway for an e-brake handle fix and oil change). They did a systems check, and replaced the battery (hey - 7 years on 1 battery isn't all bad).

When I got the car back, the odometer was one mile greater, but the trip odo was at 10.2 miles. I live more than 10.2 miles from the dealership, and I didn't touch the trip odo reset on the way there. How is that reading possible?

[gutMD]

Having just bought my car I am wondering whether or not there is any way to tell if my battery is the original OEM battery. If I could be certain it was then I might consider replacing it as it is now 6+ years into its lifespan.

[RRZ8]

Having just bought my car I am wondering whether or not there is any way to tell if my battery is the original OEM battery. If I could be certain it was then I might consider replacing it as it is now 6+ years into its lifespan.

Doesn't the baterry have a serial number which you can check ? Why don't you just check the capacity with a good tester ?

[mcorrera]

I have dead battery issues quite frequently since I don't drive my car that often. Is it OK to leave it connected to the charger all the time?

[macfly]

Yes, the car was even supplied with a trickle charger when new, both my Z8's live tethered to their battery chargers all the time.

[RRZ8]

Yes, the car was even supplied with a trickle charger when new, both my Z8's live tethered to their battery chargers all the time.

Andrew, was this on the US model only ?

[macfly]

That is a question that one of our owners in Europe would have to answer, as I don't know what came with the cars over there.

[harvey2]

The charger was not included in Canada.

Other things Canadians did not get:
DE
hardtop stand

[Juergen Wunderlich]

The charger was not included in Canada.

Other things Canadians did not get:
DE
hardtop stand

From all I know so far about the standard equipment which came with the car, the trickle charger was always part of it in all Z8s with AH VIN. All the owners with an AF VIN for the European market did not get this charger. The hardtop stand was always part of the standard equipment for all cars. Sometimes the owners miss some parts of the equipment for several reasons... You will find a complete list of the standard equipment in the club section of this board. Sorry, I do not know how to make a link to this pdf-file!

[Scott Pettit]

I need a battery tender. I thought that my car came with one but it is not in the trunk. Any other cubby that it could be in?

In the event that I need to buy one, any brand or type recommendations?

Thanks,

Scott

[macfly]

I'd suggest that the BMW one for your Z3 would be perfect. I have a pair of BMW trickle chargers, one being a Z3 charger, that I use on my cars. I'm sure they're made by some local US supplier and just have a BMW sticker on them, so I'd be sure that any trusted brand would work.

[jdillane]

I got my battery tender from BMW. Keep it on most of the time. Has worked like a charm, including through the long winter storage. Still have the original battery on my 2001, too.

[zilver8]

The battery tender that comes with the car looks to be the same as this one made by Deltran...

http://batterytender.com/product_info.php?products_id=2&osCsid=0376189bb101abaa43109b1686d9041f

[RRZ8]

I keep an eye on my discharge rate (normally below 11,89V, about 5-6 weeks, I will get my charger/discharger), the device I am really happy with is my H-Tronic (German...) AL1000 plus. I can choose a 500 or 1000 mA charging, and it will work on 2, 6 and 12 V batteries.

[Scott Pettit]

I picked up the OEM charger at the dealer. Works great.

Thanks everyone for the input.

Looking forward to putting faces to the typos next week.

Scott

[Ouray]

Add me to the list of "suddenly" dead batteries. As it was a nice day in the NE I was going to start it up and take the car out for the first drive of the season. How ironic that it was exactly the third anniversary of the day that I picked up the car. I had backed it out of the garage the week before to wash and wax it and had no issues starting the car. Guess I will be off to the dealer this weekend to pick up a new battery...

[Scott Pettit]

I suggest a battery tender.

A battery tender at the dealer is about $80 and a tender at Sears is $20.00. I have both on 2 different cars and they both work great.

Scott

[Ouray]

Thanks. I have the one that came with the car. I guess I should use it.....

[Scott Pettit]

Uh...duh...LOL

[tomfakes]

Anyone know what the warranty on a BMW OEM battery is? I just got a battery tender for the Z8 and the lights are telling me the battery may be past its prime. I got this one just before Monterrey last year, so it's not yet a year old.

[Scott Pettit]

A battery is like a cat with 9 lives. If your battery has been allowed to go dead, it's lifespan has been shortened.

I would check the fluid level. You can do this on a maintenance free battery by cutting open the label around each cap and inspecting the fluid. Use a hydrometer to test the electrolyte levels. Then charge it and drive it. You may be able to cycle some life back in to it.

All of this is, of course, if the dealer won't replace it or at least pro-rate it.

Scott

[RRZ8]

Scott, if I remember correctly our OEM batteries are maintenance free and thus sealed (?)

[Scott Pettit]

You are right.

But all maintenance free batteries can be maintained by doing what I posted earlier. I do it with all of mine as do most of my friends. In Tom's case I would see the dealer first before breaking the seals.

Oh, and life time fluids in tranny's.... most of us change them at anywhere from 60 to 100k miles.

Scott

[tomfakes]

My dealer is telling me the warranty on a battery requires 10K miles per year driving. I get the feeling I'm going to be hit up for a full price new battery when I take it in.

[macfly]

My dealer is telling me the warranty on a battery requires 10K miles per year driving.
IMHO that sounds like nonsense, I'd ask him to show you that in print from the manufacturer.

[RRZ8]

My dealer is telling me the warranty on a battery requires 10K miles per year driving. I get the feeling I'm going to be hit up for a full price new battery when I take it in.


10K miles ór BMW OEM battery-jogger? :D

[tomfakes]

Since the car is driven lightly, I can live with less life from the battery, but 9 months is pretty sucky.

This dealer also didn't get me a new battery due to the phone dis-charge issue, as mine was so new at the time (October 2000) and it was not a known problem then. I think I'll mention that.

The 2 batteries in-between lasted 7 years between them.

[jawz]

Z8 Steve -
I know of a Z8 that lost nearly 4,000 miles from the odometer when the battery was changed at the dealership. It also re-set the maintenance clock so that info was lost. After a lot of investigation and work, it was corrected, but only after replacing at least 3 electronic components (lighting module, odometer, and something else). Took a very long time too - 6 to 8 weeks.
In this instance, the mileage stored in the key, which was correct, remained "frozen". It's interesting that the key will hold the correct mileage until the odometer catches up with the key mileage. There is an advantage to this - if the odometer lost mileage, it allows you to determine how many miles were lost so the odometer can be brought back to the correct mileage. I don't believe the reverse is true if the odometer gains mileage because the key will probably "pick up" the new mileage.
All I can say is always have the dealership read the key to confirm mileage anytime the battery is replaced to check for any loss/gain in odometer mileage.

[Scott Pettit]

I'd bet my eye teeth that the dealership screwed up and caused that little problem.

Scott

[jawz]

I'd bet my eye teeth that the dealership screwed up and caused that little problem.

Scott

Nope! It was noticed prior to going to the dealership.

[harvey2]

I've installed an Interstate MTP-93 battery in my car and found some minor adjustments were necessary. The battery fit the bottom hold-downs just fine and it fills the bottom of the battery tray just right, so no problem there. The vent tube supplied by Interstate wasn't quite long enough so I had to splice in an extra 3 inches of tubing for a clean install. For a good fit under the top hold down bracket, you also have to trim about an eighth of an inch or a bit more off the fat end of their supplied vent tube and push it fully into place.

The battery is not as tall as stock so it did not snug up against the holddown bracket that crosses the top of the battery, so I fashioned a plastic spacer to fill this gap. Otherwise, it was a clean fit. I swapped the little red cover for the positive terminal from the stock battery as it fits and looks a bit better than the one Interstate supplies.

Oh, and a tip to those other ham-fisted amateurs out there...don't torque the battery terminal bolt with anything other than a nut driver (for example, don't use a socket wrench) or you will snap off the bolt. I did, and what a difficult bolt it is to replace! Had to find one in another BMW at a local wrecker.

[jim]

Hello & thank you to all Contributors, Finally happened to me too! Got in to go and "click". It was the original battery, can you believe 9 yrs !! I quickly jumped online here and, being "armed and dangerous" went to Batteries Plus, bought a Group 49 for $117. and a "Battery Tender" charger $53. Swapped the battery, started my 0041 car, (God I love it so) even did a little grommet hole under my license plate, heat shrank & hid some nice wires and Bam, done. Wonder what it would have cost at a dealer? You guys are all awesome, big thanks. Jim

[Carter Rise]

Time for my third battery (have had car since Aug 2000). I am thinking of replacing it myself - is it a simple bolt in or do I need to do anything else (reset radio codes or things)?

As an FYI, I never received a trickle charger and had to pay for the hardtop stand myself. Hardtop arrived about 8 months after the car.

[Scott Pettit]

Carter,

Whenever you disconnect your battery, you should use one of the 9v devises that plug into your lighter or you can use your battery tender.

The battery is a simple DIY that involves removing the post that secures the battery, the 2 cables and that is it. If you are buying it from your dealer, they may put it in for free.

I also HIGHLY recommend the following with all "maintenance free" batteries: slice open the seal that is around each of the 6 caps and routinely check your levels.

If you have any questions, please feel free to call me at 209-480-2271

[///M Blitz]

Time for my third battery (have had car since Aug 2000). I am thinking of replacing it myself - is it a simple bolt in or do I need to do anything else (reset radio codes or things)?


As the Geico commercial says, "it's so simple even a caveman can do it." There is a bracket that holds the battery in place (10mm bolt) and then the two battery cable brackets (13mm nuts). Simple tools like a ratchet and socket set and the tools in your toolbox should take care of it. Yes, you will have to reset the clock, but I don't remember having to reset the radio code, although you might want to have it in hand just in case.

Also, when the disconnect the battery, the alarm makes the most ear piercing noise (I'm not kidding). Get ready for that. You might even want to consider ear plugs.

Good luck.:beerchug:

[Scott Pettit]

The battery tender will eliminate the alarm and clock issues. I have never had the alarm go off.

[///M Blitz]

The battery tender will eliminate the alarm and clock issues. I have never had the alarm go off.

I've not tried replacing the battery with the tender plugged in, but I would be surprised if it makes a difference when he is in the process of replacing the old battery. As soon as the voltage drops when he disconnects the old battery, the alarm will go off. As to the clock, maybe it will keep on ticking. Nevertheless, I think as a precaution I would disconnect the tender when replacing the old battery. Why take a chance and do tons of damage, but that's just me.

[Carter Rise]

Thanks for the help. I am off to buy the battery tender.

[LarryG]

Interestingly my car was delivered in August 2000 (AH60109) without the battery tender or hardtop. The hardtop was shipped to the selling dealer many months later in a large cardboard container. It is my understanding that BMW wanted to get these cars into the showrooms as quickly as possible. The hardtops were simply behind schedule. When I purchased the car in December 09 from the original owner (with 893 miles), the hardtop was still in the container-it had never been placed on the car. The hardtop cover and carrier were included with the car as well.
Unlike the black carriers that are seen with these vehicles, mine is a bright silver color.

[Carter Rise]

I was August, as well (60186). Got the cover. Dealer called me and put the hardtop on for me, so I didn't get a crate. I guess the carrier went to someone's Z3 because I had to buy one. It's black and the wheels are now frozen on it. I'll fix it if I ever take the hardtop off the stand again.

I did get the book after putting up a big 'ol stink!

[Scott Pettit]

You should not have a problem.

The lighter is connected, as is virtually everything, via two wires to the battery. Disconnecting the battery should not do anything to anything. Be sure to turn off the radio and do NOT turn on the key until the battery change has been completed.

By plugging in an outside power source such as a charger / tender, you are just substituting the source of power to the accessories. Those little 9v gizmos do not power anything, they just supply enough power to keep memories in tact.

By the way, I've taken my batteries out of my Z8 and Z3 and other than having to reset the analog clock-no problems, no alarms, in fact-kinda boring.

[Norcal]

Got that again this week. Car had been sitting for around 4-5 mo. as I had let the registration lapse, and was driving other cars, and we had a very long, wet winter.

There wasn't even enough juice for the under-hood lights to go on, or for the key to go to the second position.
Tried to jump it. No go. Lights, key, and trunk pop worked while hooked up though.

Called local BMW parts. Got new battery and installed it... all good to go. This is the second time my car has done this since new, and I think the history is telling.

Battery 1: Spring 2001-fall 2006
Battery 2: fall 2006-spring 2010

1) Never have used the trickle charger
2) Never installed the phone, thus never had the drain problem
3) Drove the car much more the first 6 years. 28k mi? Fun backroads after work, weekend errands, events and trips, track time, DD to work part time.
4) Drove the car much less for next 3 years. 3k mi? 2-3 trips/events each year. Car sat for months at a time.
5) Got a Porsche GT3 in 07, and knew it was a lease, so give the Z8 a rest, and drive the P-car while I could. DD, track, events etc.

Verdict:
The original battery lasted about 5 1/2 years with no charger, being driven a few times a week and sometimes sitting for a month or so. The second battery lasted about 3 1/2 years with little use, sitting for many months at a time. No real mystery here, just the facts. Use it or loose it! Happily an easy fix.

[RRZ8]

Got that again this week. Car had been sitting for around 4-5 mo. as I had let the registration lapse, and was driving other cars, and we had a very long, wet winter.

There wasn't even enough juice for the under-hood lights to go on, or for the key to go to the second position.
Tried to jump it. No go. Lights, key, and trunk pop worked while hooked up though.

Called local BMW parts. Got new battery and installed it... all good to go. This is the second time my car has done this since new, and I think the history is telling.

Battery 1: Spring 2001-fall 2006
Battery 2: fall 2006-spring 2010

1) Never have used the trickle charger
2) Never installed the phone, thus never had the drain problem
3) Drove the car much more the first 6 years. 28k mi? Fun backroads after work, weekend errands, events and trips, track time, DD to work part time.
4) Drove the car much less for next 3 years. 3k mi? 2-3 trips/events each year. Car sat for months at a time.
5) Got a Porsche GT3 in 07, and knew it was a lease, so give the Z8 a rest, and drive the P-car while I could. DD, track, events etc.

Verdict:
The original battery lasted about 5 1/2 years with no charger, being driven a few times a week and sometimes sitting for a month or so. The second battery lasted about 3 1/2 years with little use, sitting for many months at a time. No real mystery here, just the facts. Use it or loose it! Happily an easy fix.

OEM battery? Is it updated to the AGM/GEL type or lead/acid?

[Norcal]

OEM. Don't know that anything is different.

[RRZ8]

OEM. Don't know that anything is different.

OK, that is the lead/acid battery. So, if I understand it correctly, you just had the Z8 standing still for months (no charger at all) and then (jump) started it? Or did you charge it completely before you planned a drive?

[Norcal]

Jump did NOT start the car. Had to go buy a new battery.