Trickle charging GL450 through a 12V socket?
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Newbie
Joined: Jan 2016
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GL450
Trickle charging GL450 through a 12V socket?
Hi folks, given that I'm driving very little, I plan to hook a trickle charger/maintainer to make sure I can always start the SUV. Because the hood is very tight, directly hooking under the hood appears a bad idea if I leave the hood struts up.
I read the manual, but couldn't find an answer about 12V sockets. Is the cigarette lighter socket a "hot" circuit for the battery? If not, will any one of the 3 sockets in the front-passenger footwell, in the rear compartment, or in the cargo compartment do the trick? Thanks!
I read the manual, but couldn't find an answer about 12V sockets. Is the cigarette lighter socket a "hot" circuit for the battery? If not, will any one of the 3 sockets in the front-passenger footwell, in the rear compartment, or in the cargo compartment do the trick? Thanks!
Super Member
Joined: Apr 2004
Posts: 625
Likes: 82
From: Germantown, MD
'07 GL450
Per GL450 Manual, Page 320:
Page 321, however, tells you to turn ON the ignition to use the outlets:
In my experience, I've always had to turn the ignition to the ON position to use the outlets (air compressor for the tires). That being said, the battery is located under the passenger seat so you could always tap into it directly.
Alternatively (and this is just a thought), you could feed the cable through the grille, or the windshield drain cowel to access the jump terminals in the engine compartment (without worrying about the hood).
You can use the power outlet in the cargo
compartment or in the front of the rear seats
even if the ignition is switched off.
An emergency shut-off feature ensures that the
vehicle’s electrical voltage does not fall below a
minimum level. If the voltage drops to this minimum level, the power outlets are automatically
switched off. This ensures that enough power remains to start the engine.
compartment or in the front of the rear seats
even if the ignition is switched off.
An emergency shut-off feature ensures that the
vehicle’s electrical voltage does not fall below a
minimum level. If the voltage drops to this minimum level, the power outlets are automatically
switched off. This ensures that enough power remains to start the engine.
Switch on the ignition (page 42).
Flip up cover and insert electrical plug
(cigarette lighter type)
Flip up cover and insert electrical plug
(cigarette lighter type)
Alternatively (and this is just a thought), you could feed the cable through the grille, or the windshield drain cowel to access the jump terminals in the engine compartment (without worrying about the hood).
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
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From: Allentown, PA
'08 GL 320 CDI
Use the underhood, positive battery post. Just drop the extension cord straight down to the ground, not via the hood. Or, if the car is kept in a garage, just slowly close the hood - but not all the way - a siginificant gap will remain.
MBWorld Fanatic!
Joined: Jun 2010
Posts: 2,762
Likes: 630
From: Emmett, ID, USA
2007 GL450
I read the manual, but couldn't find an answer about 12V sockets. Is the cigarette lighter socket a "hot" circuit for the battery? If not, will any one of the 3 sockets in the front-passenger footwell, in the rear compartment, or in the cargo compartment do the trick? Thanks!
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,119
Likes: 784
NGL450 w/EORP, S550
Hi folks, given that I'm driving very little, I plan to hook a trickle charger/maintainer to make sure I can always start the SUV. Because the hood is very tight, directly hooking under the hood appears a bad idea if I leave the hood struts up.
I read the manual, but couldn't find an answer about 12V sockets. Is the cigarette lighter socket a "hot" circuit for the battery? If not, will any one of the 3 sockets in the front-passenger footwell, in the rear compartment, or in the cargo compartment do the trick? Thanks!
I read the manual, but couldn't find an answer about 12V sockets. Is the cigarette lighter socket a "hot" circuit for the battery? If not, will any one of the 3 sockets in the front-passenger footwell, in the rear compartment, or in the cargo compartment do the trick? Thanks!
MBWorld Fanatic!
Joined: Sep 2005
Posts: 6,191
Likes: 242
From: Albuquerque
'10 CL550, '12 GL550
So, my BMW motorcycle—also featuring a CAN bus electrical system—requires a special battery charger capable of “waking up” the CAN bus circuit for a power socket. Since Mercedes doesn’t offer a similar charger, you should assume your idea isn’t feasible. Owners manual provides instructions on how to charge battery.
