Hi guys,

i have never attempted to boost my car with cables and another car. My battery on my 740 is down cause wasn't used for the last 5 months so now i have to boost it up.

Is there a procedure to do it? Any pictures or someone can explain me?

Thank you

William!

Yes....your owners manual has instructions....and its in the chapter titled...."Jump-Starting" :D

http://www.bimmerboard.com/members/q/original/Jump%20Starting%20E38%20battery.jpg

You should really consider investing in a battery or trickle charger. A battery left to sit for 5 months will experience sulfation (the sulfuric acid in the battery stops bouncing around in the electrolyte making energy and clings to the plates in the battery). This will eventually kill the battery when it's not kept charged.

I charge my battery approx every 3 weeks at 2 amps for approx 20 hours during the winter months when I'm not driving the 7 because of inclement weather. BMW recommends a 6 week recharge schedule but I find the 3 weeks to work better for me. I base my schedule on the info below:

http://www.bimmerboard.com/members/q/original/BMW%20Battery%20Charging%20Calendar.jpg

http://www.bimmerboard.com/members/q/original/Timetable%20for%20Charging%20Battery.jpg

+1 with Qsilver7

Having Qsilver7 on this forum is like having an on-line encyclopedia. It is easy to see why of all the forums out there, this one is the most popular.

Those of us who have been on this forum for a while, know where to find the owner's manual (if we don't have one), and bookmark www.e38.org for everything else. I don't know or want to know how he gets access to some of the information he posts (?industrial espionage, anyone?)....just as long as he stays with us.

Let's all hope he doesn't decide to buy a Mercedes anytime soon!!!

jake

Ahhh, thanks...I'm humbled by your kind words...although some of the new MB's and Audi's look nice...it would take a lot to get me to jump ship. :D

Well, thanks for the explanations, i followed as showed but unfortunatelly the battery is completely out and didn't work... so i will probably just change the battery and make sure i will not do the same mistake again. :)

Is there any procedure AFTER changing the battery? Like putting back the code in the radio?

Thanks

William!

What code would you put into the radio? :stickoutt

The answer is none...you weren't given a "code" for the radio because the e38 doens't use an anti-theft radio like in the e32 7 series. :) Your e38 uses a multiple and model specific set up to reduce the probability of theft. Your car has either a MID (multi-informational display) and a seperate cass/tape unit that houses the radio reciever (or a Nav monitor with the radio reciever residing in the trunk). If you have the MID/ cassette tape set up...your MID controls the volume, stations, bands, etc...and only fits in the e38...the MID in the e39 & e36/e46 etc aren't interchangable...and neither are the dash cassette or indash CD units.

The only thing you'll need to reset is the clock...and you will loose your OBC features that have been averaging your mileage and gas mileage....and the "remote" features you have programmed from the OBC into the CCD (check control display). But all of that is VERY easy to reprogram.

If you buy or make-up one of those little units that has a 9-volt battery hooked up to a connector that fits into your cigarette lighter...then you won't even loose any info at all. Or if you have a trickle charger (like 2 amps)...you can connect that to the negative/positve) jump locations under the hood...then CAREFULLY remove the cables from the battery MAKING SURE that they don't touch...and also save your OBC features from starting over.

And DON"T forget to hook your new battery up to the VENT TUBE at the rear of the battery compartment....your battery MUST be vented!!!!! ;)

I called to have the cost of the battery today and OUCH :eek: a stunning $342.00 from the dealer (just the battery) so i was wondering...

if i connect the boost cables from my car to the BM battery let say for an hour or so, would the battery take some juice and start recharging and where would i plug the NEGATIVE in the BM?

Is this possible?? I'm trying to see if i can save myself 350$ :eyecrazy

thanks

William!

...if i connect the boost cables from my car to the BM battery let say for an hour or so, would the battery take some juice and start recharging and where would i plug the NEGATIVE in the BM?

William!

Not sure if you read the instructions in post #2...but the positve jumper cable goes to the remote post below the flip-up cover under the hood...and the negative cable gets connected to the hex shaped bolt on the driver's side shock tower (under the hood). There 's no need to hook the cables up directly to the battery in the trunk...because the remote location under the hood provides the same access.

If you tried to jump the car before and did NOT hook up the negative cable...that could be why the car still didn't start. Or perhaps you didn't let the battery charge long enough before trying to start it. DO NOT leave the car's jumpered together for an hour...that's too long for that type of procedure....but connect the two cars together (and leave the healthy car running) for a good 3 to 5 minutes...then try to start your car.

If you've unlocked the OBC...you can turn your e38's ignition to position 1 and do TEST #9 and watch to see if the battery is charging...the voltage should go up.

http://www.bimmerboard.com/members/q/original/Jump%20Starting%20E38%20battery.jpg

Not sure what offerings of batteries are available where you are...but what you need is a class size 49 or class size 95 battery. The 95 class size battery is what the BMW replacement battery is...and is the more expensive of the two types.

But a 49 class size battery is usually more than adequate....here in the States...we can get them from places like AutoZone (the Duralast 49 DL) or the Interstate MTP-93.

Check out www.interstatebatteries.com to see if there are any local vendors near you that sell the MTP-93...that's about the only after market brand battery that I know of that may be sold in Canada as well as the USA.

What code would you put into the radio? :stickoutt

The answer is none...you weren't given a "code" for the radio
Don't suppose he's thinking of the code in the OBC for the imobiliser?

Cheers,

TSC.

DO NOT leave the car's jumpered together for an hour...that's too long for that type of procedure....but connect the two cars together (and leave the healthy car running) for a good 3 to 5 minutes...then try to start your car. THAT IS ONE THING I DIDN'T DO. I CONNECTED THEM AND TRIED TO START RIGHT AWAY. I SHOULD HAVE WAITED! :bash

If you've unlocked the OBC...you can turn your e38's ignition to position 1 and do TEST #9 and watch to see if the battery is charging...the voltage should go up. I GUESS THE TEST #9 IS WRITTEN ON THE BOOKS!?!?

I'm gonna try it again tomorrow leaving it for a couple of minutes and see what happens. Do i just have to leave it with the KEY turned off or do i have to put the key on position 1 while waiting?

Man just put a battery in that bad boy thats close or the same size. No matter how you put it the battery is 12v nothing more nothing les. Dont let all this gibber shizz get you goin. A battery is a battery is a battery.

I GUESS THE TEST #9 IS WRITTEN ON THE BOOKS!?!?



No, unlocking the OBC and TEST #9 is NOT written in the books...but has been posted on many BMW forums found doing a search...here's a direct link to the instructions on how to UNLOCK your OBC...once unlocked...you can access the 21 (hidden) information that you can get from your car's OBC: http://www.bimmerboard.com/forums/posts/260614/

If the car loses it's power source (battery is disconnected)...the OBC will be locked again.

Most of the time, if a battery goes completely dead, or does not have enough voltage to turn the engine over a couple of times before dying, you will need to remain connected to the donor vehicle for a good three to five minutes. This will 'cook' your battery so that small bubbles will rise to the surface of the individual cells, assuming you were to take the covers off and look. Once these bubbles start to form, your battery is taking a charge, and if the engine is in good shape, it should crank over several times, enough to get the engine running. Leave your ignition off until ready to start the car, and once the car is running have the donor vehicle driver quickly disconnect the cables. It also helps if the donor vehicle is running up around 2000 rpms.

These bubbles give off a gas, and is one of the reasons our batterys are vented. This gas is quite flammable, by the way.

It is a good (!!!) idea to unlock your OBC and periodically run test #9 especially if you have an old or aging battery. You will notice fluctuations in voltage when it is no longer accepting a charge (13.7 plus or minus a few tenths volts is considered normal).

jake

well, i tried and left the car there for 20 minutes and did charge a bit the battery cause now when i open the doors, i can see the lights etc. but i think the winter was really tough on the oil and everything else and the car dont seem to have the energy to start. I dont even if i brand new battery will do anyways....

It's like the motor doesn't even want to TRY to start... maybe oil is still frozen... who knows! You can just ear a TIC TIC sound when you try to put it on and nothing else happens !!!?!??

Thanks guys but i think i will have to get her towed and bring it to a dealer.:mad

William!

from your last description...save the money from a probably not needed tow...and use it toward the purchase of a battery.

Refer to the 2nd paragraph in image below under "SITUATION" which was also posted back in post #2. Long term sulfation will KILL your battery. If it is dead...not amount of charging and jumping is going to bring it back to a level that will start your car.

Your latest attempt gave the battery enough power to illuminate the interior lights...but your no start situation is from the battery not having enough power to start the car.

YOU NEED A NEW BATTERY. Unless it is like 75 degrees below zero (F)...your car's oil is NOT frozen. To replace the battery...just remove it from the trunk...you don't need to tow your car in for that.

BTW...while the battery had enough juice to illuminate the interior...did you unlock the OBC so that you could get a reading of the battery's voltage?

http://www.bimmerboard.com/members/q/original/BMW%20Battery%20Charging%20Calendar.jpg

http://memimage.cardomain.net/member_images/7/web/739000-739999/739005_80_full.jpg

http://memimage.cardomain.net/member_images/7/web/739000-739999/739005_149_full.jpg

Ok thanks everyone... i guess i have to try with a new battery... but do i have necessarly go get a BMW one at 350$ or can i go to Club Price and buy one or Canadian tire and buy one?

thanks

William!

See post #10 & post #17. Perhaps the pictures in post #17 didn't load up...because neither of them are BMW batteries but are examples of class size 49 batteries that were installed in an e38.

Hi guys and thanks for all the information given to me...

i finally changed the battery today and the first shot the car started... i will redo the programming tomorrow for the time and i would like to check the OBC and do some tests...

if i have other questions, i will know where to go!

Thanks again

William!

qsilver - Is the battery in your picture vented? I've been doing quite a bit of work in my trunk this week (had to tighten down the rear trunk lid latch to keep it from re-locking) and I am now worried that my battery isn't vented. Any advice would be exceptionally useful.

qsilver - Is the battery in your picture vented? I've been doing quite a bit of work in my trunk this week (had to tighten down the rear trunk lid latch to keep it from re-locking) and I am now worried that my battery isn't vented. Any advice would be exceptionally useful.

Yes, if you are referring to the Interstate battery...it is vented. The vent on the Johnson Control mfg'd battery (which the duralast and Interstate are 2 of several)...the vent is in the center of battery/top side...and you can see it in the pic...there's a black tube that is running from the center of the battery toward the rear quarter panel...and somewhere under the insulation...it connects to a light gray colored tube that is running toward the corner at the rear of the battery compartment area where it vents to the exterior of the car.

It's really important that your car's battery is vented...and is worth the small effort to double check. You should be able to reach/see/feel back there to see if the tube is fee or hooked up. :)
http://memimage.cardomain.net/member_images/7/web/739000-739999/739005_149_full.jpg

You can also see the Duralast vent tube kit attached to the car's gray vent tube in the pic below:
http://www.bimmerboard.com/members/q/original/E38%20Battery%20Vent%20Hose.jpg