Grounding Wires

Dec 28, 2019 | 02:49 AM

Henry Stark

Thread Starter

Senior Member

Joined: Nov 2018

Posts: 253

Likes: 40

GLC63S

Grounding Wires

I was looking to hardwire my battery tender and was wanting to use an existing ground. There are several grounding points but wasn’t sure if they were part of the 48 volt system and if I could even ground the 12 volt system to the same point?

Last edited by Henry Stark; Dec 28, 2019 at 03:35 AM.

Dec 28, 2019 | 09:20 AM

Hurricane1938

Junior Member

Joined: Oct 2018

Posts: 62

Likes: 22

From: Long Island, NY

GLE450W4

Have you checked page 479 of the manual:

Notes on starting assistance and on charging

the 12 V battery Vehicles with a lithium-ion battery

When charging the battery and during starting

assistance, always use the jump-start connection

point in the engine compartment.

Dec 28, 2019 | 10:34 AM

Henry Stark

Thread Starter

Senior Member

Joined: Nov 2018

Posts: 253

Likes: 40

GLC63S

Quote:

Originally Posted by Hurricane1938

Have you checked page 479 of the manual:

Notes on starting assistance and on charging

the 12 V battery Vehicles with a lithium-ion battery

When charging the battery and during starting

assistance, always use the jump-start connection

point in the engine compartment.

I charge my batteries religiously and don’t want to use the clamps. Instead of running the cord directly to the battery which is a pita to get to under the seat I was going to use the terminal nut on the jump connection and the ground closest to the front fender/firewall. I just have to determine if this ground is suitable for 12v devices.

“There is a common ground for the 12/24-
volt system and the 48-volt system, which are connected via physically separate grounding bolts/connections.”

https://www.zvei.org/fileadmin/user_...-engl-2016.pdf

Dec 28, 2019 | 04:22 PM

Hurricane1938

Junior Member

Joined: Oct 2018

Posts: 62

Likes: 22

From: Long Island, NY

GLE450W4

I haven't digested all 40 pages of the ZVEI treatise on 48 Volt Electrical Systems (it is interesting), but the GLE Owners Manual (page 481) specifies the brass ground near the left front fender (on US spec vehicles) and proximate to the positive terminal as the appropriate ground to use when charging the 12 volt battery.