Battery Replacement Info

[m3f_jkemmet]

First I would like to thank you all for the great information and advise that is provided on this Forum. Being new to the BMW/M3 the Forum has become a very intricate part of my pre-purchase and learning process of this very cool vehicle. Thanks!



I have a question regarding the purchase of a Battery. The car in question is a 1999 M3 Convertible. Based on the recommendations from doing a search the Interstate MTP91 seems to be the direction I am headed. However, the Bentlley Manual recommends that a special insulated battery is required for convertibles. Any thoughts and/or concerns with not going this route?



Your input would be appreciated.

[m3f_Richardsperry]

I've never seen a vert battery, but I suspect you could look at it and see if there is potential for shorting it out. You could simply use a -91 and just insulate the posts.

[m3f_jkemmet]

Thanks for the replay. But, it is my understanding that it is more for vibration if I am understanding this correctly.

[m3f_scoobiedoo2029]

Thanks for the replay. But, it is my understanding that it is more for vibration if I am understanding this correctly.

i dont know if thats anything i would care about. vibration can separate plates in batteries but the e36 vert cant be generating so much more vibration then a stanced car sitting on its bumpstops on a pothole filled city street that youll break batteries and they dont...


i always used interstate batteries, never had a issue untill there like 6 years old and its cold out. like the autozone batteries its garentied for like 2 years so if its an issue youll get a new one, and youll be able to cash in on a new battery till they catch on.

[m3f_badgtho]

I'm not familiar with that recommendation. I'd use the mtp91 or other group 91 vented battery . I have a napa group 91 in my e30 convertible and have not had it vibrate apart.

[m3f_B329iC]

I have heard of the "special" battery. I recently replaced mine with a Bosch 92-640B which is a battery specially for the convertible. A lot of people will use other batteries that fit and have the correct or higher CCA and have no problems. From the worst I have heard you might lose a year on the total life of the battery. I got mine on sale so it was only about $10 more so I got the correct one.

[m3f_hencini]

Thanks for the replay. But, it is my understanding that it is more for vibration if I am understanding this correctly.

I've read this, too. But I've never heard anyone talk about actually finding one and using it. Then again, I don't know many vert owners.

I'm not familiar with that recommendation. I'd use the mtp91 or other group 91 vented battery .

Yup. The Interstate MTP-91 is a boss. I think mine was 8 years old and still going strong when I finally quit playing battery roulette and replaced it before it left me stranded on a cold Wisconsin winter night.

[m3f_enderw88]

I think mine was 8 years old and still going strong when I finally quit playing battery roulette and replaced it before it left me stranded on a cold Wisconsin winter night.

I was proud of you for that decision!

[m3f_RickO1]

Thanks for the replay. But, it is my understanding that it is more for vibration if I am understanding this correctly.

I think vibration is only a significant issue if the battery gets in a low charge state. If you keep it charged up, either by driving the car frequently or keeping it on a battery tender, I don't think you'll have a problem.



+1 on the MPT-91.

[m3f_hencini]

I was proud of you for that decision!

Hey, just saw that you ride. Do you ever get into the motorcycle subforum? I'll file the Ballabio under bikes to consider in the future... It's a beauty...

[m3f_M_Parallel]

You are right. There is a vert specific "anti rattle" battery available.


However on our verts, the whole battery tray is a special tray suspended within the car's chassis with a big anti vibration damper on one end. So running a regular battery won't hurt.


In my 328i I have a normal battery, in my M3 an OEM vert specific battery.


BMW P/N 61.21.2.158.447 "RÜTTELFEST" = German for anti rattle.

[m3f_enderw88]

Hey, just saw that you ride. Do you ever get into the motorcycle subforum? I'll file the Ballabio under bikes to consider in the future... It's a beauty...

Haven't ever bothered to go there. I love the Ballabio, but I was really wanting heated grips yesterday riding home in an unexpected 37 degree rain storm...

[m3f_hencini]

Haven't ever bothered to go there. I love the Ballabio, but I was really wanting heated grips yesterday riding home in an unexpected 37 degree rain storm...

That is not my idea of a good time.



I won't ride unless it's sunny and over 50 degrees.

[m3f_scoobiedoo2029]

k i built a solar charged electric go kart that runs off car batteries/ deep cycles depending on what i can scavenge for cheap. myself and many of my friends use this thing as a mobile beer cooler, we have jumped this thing, crashed into trees, and flown down off road surfaces at high rates of speed, the thing will do about 30mph at 32v an not like a gas powerd engine, it means 30mph immediately uphill, it is not safe. and of the pile of batteries ive killed on this thing, its only been from letting it get to low more then once. only one time did i break a cell off a battery or see any abnormal charging or any other changes someone possibly myself hit something very hard with it. this thing has NO suspension and is driven by drunken idiots if vibration was a huge issue i would have found out what it does doing 50 mph downhill in a cornfield. but a large corporation like bmw may see the one in a million chance of plate failure or terminal corrosion/separation to be worth effort of a stronger battery. for the average consumer, i would not worry.





going hybrid, installing a 5hp briggs at the moment. i try not to run car batteries because of the liquid inside, but gell cell deep cycles are not cheap. hopefully one day i can afford a pile of used laptop batteries an not have lead slowing it down. oh this was a new axel install because the old one with the skinny tires god bent from jumping the thing, also had to replace the whole front end from hitting a tree.

[m3f_hencini]

k i built a solar charged electric go kart that runs off car batteries/ deep cycles depending on what i can scavenge for cheap. myself and many of my friends use this thing as a mobile beer cooler, we have jumped this thing, crashed into trees, and flown down off road surfaces at high rates of speed, the thing will do about 30mph at 32v an not like a gas powerd engine, it means 30mph immediately uphill, it is not safe. and of the pile of batteries ive killed on this thing, its only been from letting it get to low more then once. only one time did i break a cell off a battery or see any abnormal charging or any other changes someone possibly myself hit something very hard with it. this thing has NO suspension and is driven by drunken idiots if vibration was a huge issue i would have found out what it does doing 50 mph downhill in a cornfield. but a large corporation like bmw may see the one in a million chance of plate failure or terminal corrosion/separation to be worth effort of a stronger battery. for the average consumer, i would not worry.







going hybrid, installing a 5hp briggs at the moment. i try not to run car batteries because of the liquid inside, but gell cell deep cycles are not cheap. hopefully one day i can afford a pile of used laptop batteries an not have lead slowing it down. oh this was a new axel install because the old one with the skinny tires god bent from jumping the thing, also had to replace the whole front end from hitting a tree.

I have a whole new level of respect for you.