Mercedes-Benz Metris Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
625 Posts
Discussion Starter #1
Hi all: I have an idea for installation of the AiLi (or eq) battery monitor shunt -- namely, why not dump the plastic base and connect it directly to the house battery terminal? See the pix below.

First, here's the shunt as it comes from the factory. It appears to be fastened to a pretty stout plastic base.
18501


On closer examination, it comes apart easily and cleanly --

18502



Leaving open the possibility of removing the plastic base and swapping out one of the AiLi brass(?) hex nuts for a "military-style" battery terminal using a 2 1/2 inch 3/8" hex instead of the square head terminal bolt.
18503



With the end result being one less device to mount in my power box, and the shunt parts are all pointing in accessible directions.
18504



I'd really like to do this to conserve cabling and because I think it's very sanitary as an install. I am concerned about the possibility of some kind of galvanic corrosion where the AiLi brass and/or copper pieces contact the zinc-plated terminal bolts.

Does anyone have any comment on this install approach? Admittedly, it doesn't save a lot of work -- just two cable crimps and mounting the plastic base, but as I said, at least as long as I am using a battery with appropriate terminals, this approach looks much cleaner to me.

Thanks!
 

·
Registered
Joined
·
625 Posts
Discussion Starter #2
As I cogitate, I'm not sure I like the B+ positive line so close to the battery terminal (I'm going to fuse it at like 3A anyway).
 

·
Registered
Joined
·
625 Posts
Discussion Starter #4
They are twins indeed! Not sure how well organized the Chinese communist factory system is, but it looks like central command allows but one shunt manufacturing plant --
 

·
Registered
2016 Cargo converted into a camper van
Joined
·
309 Posts
You could try a corrosion inhibitor to reduce the galvanic corrosion. Looking on a boating forum might be worth while for ideas on corrosion inhibitors and their effectiveness. Here is one example- Galvanic Corrosion Inhibitor - 3.5 oz. Squeeze Tube Of course Amazon has a number of options too.

One other possible concern is the potential for stress on the battery terminal. You'd certainly want to have the cable attaching to the "P" terminal well secured so that it does not exert any leverage on the battery.

I'd be inclined to find a bronze bolt to go through the battery lug and into the shunt. If you do have corrosion, it would probably be cheaper and easier to replace that bolt or the battery lug rather than the shunt.
 

·
Registered
Joined
·
625 Posts
Discussion Starter #6
You could try a corrosion inhibitor to reduce the galvanic corrosion. Looking on a boating forum might be worth while for ideas on corrosion inhibitors and their effectiveness. Here is one example- Galvanic Corrosion Inhibitor - 3.5 oz. Squeeze Tube Of course Amazon has a number of options too.

One other possible concern is the potential for stress on the battery terminal. You'd certainly want to have the cable attaching to the "P" terminal well secured so that it does not exert any leverage on the battery.

I'd be inclined to find a bronze bolt to go through the battery lug and into the shunt. If you do have corrosion, it would probably be cheaper and easier to replace that bolt or the battery lug rather than the shunt.
Thanks so much. Whenever I ask this kind of question, I know I don't trust the idea (I saw it in some video clip). Worth a try. I'll just crimp another cable.

I'm slowed because I'm now liking the idea of using the box for the front 12v/15A plug and 3A USB QC3.0 instead of the side Con-pearl panel. More drilling!!
 

·
Registered
Joined
·
625 Posts
Discussion Starter #8
I found that some 12" cables take all the stress off everything.
I used a Blue Sea MRBF fuse block on my battery: Dual MRBF Terminal Fuse Block - 30 to 300A - Blue Sea Systems
One 50A for the main feeds and a 300A for my inverter. This plus a 12" length of 1/0 AWG Marine wire with terminals to the shunt made my life better.
I am using a single 100A terminal fuse on the house battery out, and a 40A AMI on the DC-DC to battery + out (where I used 8 AWG cable for a sub-three foot 30A max run).

18555
18557
18558


18559
 
  • Like
Reactions: brow
1 - 8 of 8 Posts
Top