Bimmerfest BMW banner

41 - 60 of 85 Posts

·
Registered
Joined
·
453 Posts
Discussion Starter #41
I’ve let mine sit for months at a time in a 4.5 year old battery and t starts instantly. My folks leave their VW for 6 months, no issue starting. If you sit and drive only a couple miles, especially with various heaters on, yes you’ll see low voltage issues, but I’ve seen those issues while driving, not after sitting.

A battery tender is compensation for an underlying problem. If you need a battery tender for only 2 weeks of sitting, you DEFINITELY have a problem.

I don’t like “could be” in-person diagnostics. You’ll get a new battery and two weeks later not be able to start the car. I’ve seen it time and time again.


Sent from my iPhone using Bimmerfest
That's what I was thinking. I don't think it's right for a car to sit on a trickle charger because it dies. My folks have a 2018 Mercedes Benz E class which has way more electronics and it sits for about the same time my BMW does (1-2 weeks) without being driven. It starts right up regardless. I'm gonna let the car sit without a charger and see how long the battery last.
 

·
Registered
Joined
·
453 Posts
Discussion Starter #43
Disconnect the negative and let it sit. If the battery loses charge you need one. If it doesn’t, you have a parasitic draw. Write down before and after voltages.


Sent from my iPhone using Bimmerfest
I think I'll let the car battery charge to 100%. Then note the Volts of the battery without starting it. After, I'll pull the negative cable off the battery. When I need to use the car or so, I'll plug the negative cable back. If the battery loses charge then I'll order a new battery. If it doesn't, that means something is running while the car is off? The car falls "asleep" though. So what can be running?
 

·
Registered
Joined
·
453 Posts
Discussion Starter #46 (Edited)
Disconnect the negative and let it sit. If the battery loses charge you need one. If it doesn't, you have a parasitic draw. Write down before and after voltages.


Sent from my iPhone using Bimmerfest
So battery voltage right now is 12.37V (without start). The battery was fully charger this morning per trickle charger before I took it too advanced auto. I just pulled the negative cable off. Will need to pull the car out of the garage Friday to take the lawn mower out. So, let's see what the volts are in 5 days.
 

·
Registered
3/2007 328xi E91
Joined
·
2,821 Posts
WHICH of the 316 posts in that thread do you suggest offers ANY "Enlightening Information"???
That's ridicules
:thumbup: It's ALSO Ridiculous! ;) When the vehicle enters "Sleep Mode" 15 to 30 minutes after shutdown (depending upon whether Locked or NOT) current draw is ~ 15 mA (milliamp) or .015 Amp. You do the math on how long that would take to drain a 90 Amp hour Battery. :tsk:

Yo -- Yukoner! You were going to let us know how your E9x fared in Airport parking for 3 weeks. Any report yet?/Did I miss it? :)

Thanks,
George
 

·
Registered
Joined
·
453 Posts
Discussion Starter #50 (Edited)
WHICH of the 316 posts in that thread do you suggest offers ANY "Enlightening Information"???
That's ridicules
<img src="http://s1.bimmerfest.com/forums/images/smilies/thumb.gif" border="0" alt="" title="Thumbs Up" class="inlineimg" /> It's ALSO Ridiculous! <img src="http://s1.bimmerfest.com/forums/images/smilies/icon12.gif" border="0" alt="" title="Wink" class="inlineimg" /> When the vehicle enters "Sleep Mode" 15 to 30 minutes after shutdown (depending upon whether Locked or NOT) current draw is ~ 15 mA (milliamp) or .015 Amp. You do the math on how long that would take to drain a 90 Amp hour Battery. <img src="http://s1.bimmerfest.com/forums/images/smilies/jpshakehead.gif" border="0" alt="" title="Tsk" class="inlineimg" />

Yo -- Yukoner! You were going to let us know how your E9x fared in Airport parking for 3 weeks. Any report yet?/Did I miss it? <img src="http://s1.bimmerfest.com/forums/images/smilies/smile3453453.gif" border="0" alt="" title="Smilie" class="inlineimg" />

Thanks,
George

I always lock the car:thumbup: I have the negative cable unplugged to see to if the voltages change once I plug it back on after 4 days. Noted that before I unplugged the cable, the battery voltage was 12.37V (a little on the low side). Let see what the voltage is in 4 days
 

·
Registered
3/2007 328xi E91
Joined
·
2,821 Posts
I always lock the car... I have the negative cable unplugged to see to if the voltages change once I plug it back on after 4 days.
If you have Disconnected the (-) Battery Terminal, closed the Trunk and Locked the Vehicle, do you have a mechanical key tumbler on the trunk lid? Do you have a "Plan" for opening the Trunk?

There are ways (Hope you did NOT disconnect the (+) Battery Terminal), so just let us know if you DON'T have a trunk keyhole. Also you don't say WHAT chassis you have, as that matters as well.

Basically use the Mechanical Key to unlock driver door; open hood; attach Power Source to Jumpstart Terminals under Hood; Press Interior Trunk Release Button. This works as long as (+) Battery Terminal is NOT removed and in contact with Chassis.

George
 

·
Registered
Joined
·
453 Posts
Discussion Starter #52
If you have Disconnected the (-) Battery Terminal, closed the Trunk and Locked the Vehicle, do you have a mechanical key tumbler on the trunk lid? Do you have a "Plan" for opening the Trunk?

There are ways (Hope you did NOT disconnect the (+) Battery Terminal), so just let us know if you DON'T have a trunk keyhole. Also you don't say WHAT chassis you have, as that matters as well.

Basically use the Mechanical Key to unlock driver door; open hood; attach Power Source to Jumpstart Terminals under Hood; Press Interior Trunk Release Button. This works as long as (+) Battery Terminal is NOT removed and in contact with Chassis.

George
Ohhhh I've read a lot of horror stories of people closing their trunks and not being able to open it. Car is also unlocked. My car has the trunk key tumbler and I didn't fully close the trunk. :thumbup:
 

·
Registered
Joined
·
453 Posts
Discussion Starter #53 (Edited)
Alright, it's been a day since I took the negative battery cable off. I just plugged the negative cable back and took a look at the battery voltage. It dropped from 12.37V to 12.22V.
 

·
Registered
Joined
·
3,273 Posts
Alright, it's been a day since I took the negative battery cable off. I just plugged the negative cable back and took a look at the battery voltage. It dropped from 12.37V to 12.22V.

Your battery never started with a Full Charge, at 12.37V it was only about 80%, and at 12.2V inow t is only 60%. And sitting disconnected yet dropping that much is NOT good!
 

·
Registered
Joined
·
453 Posts
Discussion Starter #55
Your battery never started with a Full Charge, at 12.37V it was only about 80%, and at 12.2V inow t is only 60%. And sitting disconnected yet dropping that much is NOT good!
Looks like it might be time for a new battery soon. The time clock was gone too when I turned it on
 

·
Registered
Joined
·
453 Posts
Discussion Starter #57 (Edited)
If you disconnected the battery, one expects the clock to have lost track of time!
Oh yeah :eeps. I'll start looking for batteries then. I know Advance Auto has a sale going on there batteries 20% off.. Home Depot has Excide batteries on sale for $120.
 

·
Registered
Joined
·
453 Posts
Discussion Starter #60
I let the battery charge fully overnight (12.49V) took the negative cable off in the morning (8am). Just got home (5pm), attached the negative cable back on and the volts dropped to 12.32V. Car started without hesitation.
 
41 - 60 of 85 Posts
Top