[nj335i]

I haven't driven my car much the past 3-4 weeks, and the battery died this Saturday. I found it unusual that within such a short period of time, the battery was able to almost fully drain itself. *Almost* because comfort access system still allowed me to get into the car. When I pressed the start button, it gave a bit of a chug before it gave up the ghost. My question is, because I have the Helix Attache on "full time hot" due to my comfort access, would it drain my battery in 2 weeks of total non-use? Prior to that, I would drive it once or twice a week, but only for short trips.

FYI, my Mini revived the Bimmer via jumper cables. The Mini had gone over a month without use and didn't have an issue starting.

[oddjob2021]

Originally Posted by nj335i

I haven't driven my car much the past 3-4 weeks, and the battery died this Saturday. I found it unusual that within such a short period of time, the battery was able to almost fully drain itself. *Almost* because comfort access system still allowed me to get into the car. When I pressed the start button, it gave a bit of a chug before it gave up the ghost. My question is, because I have the Helix Attache on "full time hot" due to my comfort access, would it drain my battery in 2 weeks of total non-use? Prior to that, I would drive it once or twice a week, but only for short trips.

FYI, my Mini revived the Bimmer via jumper cables. The Mini had gone over a month without use and didn't have an issue starting.

I'm not an electronics buff but maybe you have a short, or are grounding the battery somewhere. do you have any extra lightings like ballists or relays somewhere where it could possibly just drain? I just doubt its the piggy back because the car was in "sleep mode"

[Lane]

Yes, happened to me with V1. Try to avoid it since something can go wrong with progman when battery drains. I lost aux-selection in my radio. I cannot get it back since I don't want the latest progman.

[ralph@helix]

If the car's been sitting for a month possibly but I'll ask Eric and Mark about that.

[munters]

I just disconnect every time im not in town for more then 2 weeks.

It's known with all the Electronic in our car it can not charge it properly anymore if you drive just short distances.

[e90AW335i]

It probably has to do with the fact that the Attache is on a constant power source, not switched.

[nj335i]

Originally Posted by ralph@helix

If the car's been sitting for a month possibly but I'll ask Eric and Mark about that.

Thanks Ralph - can you report back with what they think?

Originally Posted by munters

I just disconnect every time im not in town for more then 2 weeks.

It's known with all the Electronic in our car it can not charge it properly anymore if you drive just short distances.

Seems kind of troublesome... I can't leave my trunk open because my car is parked in a parking structure.

Originally Posted by e90AW335i

It probably has to do with the fact that the Attache is on a constant power source, not switched.

That's what I thought... Why is it that JB3 and V3 doesn't have this issue even with comfort access cars? They don't need to be on constant power?

[mistermojorizin]

Originally Posted by nj335i

Seems kind of troublesome... I can't leave my trunk open because my car is parked in a parking structure.

you can lock the trunk and then open it with your metal key that's inside the FOB

[Acap14]

This is normal for bmw's, these cars need to be driven. The modules wake up every so often and "talk" to each other, which drains power from the battery. If you know you're gonna be leaving your car for awhile i recommend getting a trickle charger, to prevent this from happening again.

[e90AW335i]

Originally Posted by nj335i

That's what I thought... Why is it that JB3 and V3 doesn't have this issue even with comfort access cars? They don't need to be on constant power?

Because they used switched power. With JB3 it is even better because you dont need to tap for an external power source.

[scalbert]

Originally Posted by e90AW335i

Because they used switched power. With JB3 it is even better because you dont need to tap for an external power source.

Perhaps easier but stating better will need to be reserved until later. Using 5 VDC from a sensor power supply will work well in the implementation, the effects of the additional load over several years is unknown.

[nj335i]

Originally Posted by mistermojorizin

you can lock the trunk and then open it with your metal key that's inside the FOB

Forgot about that... I guess it's easy to forget when you can't normally see the keyhole.

Originally Posted by e90AW335i

Because they used switched power. With JB3 it is even better because you dont need to tap for an external power source.

I believe the Attache can operate with switched power, but because I have comfort access, they told me that it has to be on constant power.

[Tuned335i]

Originally Posted by e90AW335i

Because they used switched power. With JB3 it is even better because you dont need to tap for an external power source.

Originally Posted by scalbert

Perhaps easier but stating better will need to be reserved until later. Using 5 VDC from a sensor power supply will work well in the implementation, the effects of the additional load over several years is unknown.

I don't consider the need to tap the green power connector a drawback so "better" is a matter of opinion. I also used to obsess about hiding the ground wire. But any tune is going to come out before the car ever sees a dealership, so hiding a ground wire or spending a couple extra minutes hooking up a direct power connection is irrelevant

FWIW, I went more than 2 weeks several without driving my car several times when I had V1.47, and never had any battery issues.

[raceyBMW]

Originally Posted by nj335i

Forgot about that... I guess it's easy to forget when you can't normally see the keyhole.



I believe the Attache can operate with switched power, but because I have comfort access, they told me that it has to be on constant power.

I was going to ask if you have CA. The key has a battery that needs to be recharged, and to do that you need to leave it in the ignition/key-slot once in a while. If the key does not have proper charge, then it will not be able to transmit the internal codes to by-pass the starter disabler, and you won't be able to start the car. Try leaving your key in the ignition for a while if you can and then see if that helps.
http://www.bmw.com/com/en/insights/t...ic_immobiliser

If it's not that, then bring the battery in to Autozone to get checked, and if it gets checked out OK then its most likely and alternator/starter issue and bring it into the dealer!