Where to put shunt

You're sure you're not just venting spare electrons out the pipe there ? :)

I have good ventilation in the front cargo bay of the 5er, so I break all the rules about putting things near batteries. Got away with it so far (a few years or so)

On the "load side" of the shunt, I have a length of copper pipe which takes any clamps I might use from portable chargers. Also for the neg wires from any solar controller(s) I am using in the 5er. (I now have clamps on my controller output wires, which I mount in a portable sort of way to swap between 5er and TC.)

I recently flattened part of that copper pipe and drilled a hole in it to bolt more neg wire lugs that don't go on the inverter neg terminal "buss."

Here is a photo of my set-up a couple of years ago, which has since changed somewhat, but you get the idea.

Keep shunts, buss bars, fuses and breakers as far away from a flooded battery as possible. A proper hookup will have one single solitary cable connecting the positive post and one single solitary cable connecting the negative post. Of course battery paralleling bridge wires are not counted.

The shunt's milliamp wire terminals should be soldered. The contact point to the shunt's metal should be mirror bright then a coating of NON PETROLEUM BASED sealer applied over-top. I am so fussy about shunt connections I solder the wires direct to the shunt metal.

I picked up a lab grade Manganin shunt on eBay. Before the internet here took a dump. I would love to find a 4-1/2 digit 100 mv 100-amp meter, but where? I can't even search for one. Grrrr...

Exactly.. EVERYTHING, including and especially the inverter are on the load side of the shunt. I pull 180A through mine and it barely gets warm. Heat= loss

melton wrote:
Nothing should be between the inverter and the batteries but the connecting cables. But other than that, the shunt can go anywhere in the battery circuit. However, the shunt can get hot, so locate it in a safe, ventilated place.

Wrong. The Trimetric needs to see the DC amps drawn by the inverter from the battery bank. The inverter neg input goes from the outer end of the shunt to the inverter. That means the wire from the shunt to the battery has to be fat

DanNJanice wrote:
The shunt should be mounted where ALL current out-of and into the battery is monitored. It does not matter where in the line PHYSICALLY it is mounted, as long as all ELECTRICAL current from/too the battery passes through it.

Correct !

And in an RV, this usually necessitates mounting at the battery bank

unless you re-route the main cables to BUSS-BARs in another compartment

Nothing should be between the inverter and the batteries but the connecting cables. But other than that, the shunt can go anywhere in the battery circuit. However, the shunt can get hot, so locate it in a safe, ventilated place.

JRRNeiklot wrote:

BFL13 wrote:
Please say what monitor the shunt is for. A battery monitor like the Trimetric takes all the neg wires to its shunt and then just one fat wire to the battery neg post.

A solar monitor only monitors the solar so it's shunt is upstream of the Trimetric

Trimetric 2030-RV

The manual is on-line at Bogart if you don't have one.

The battery neg post only has the one fat wire from the Tri shunt. (The wires linking the batteries in a bank stay though, so you could have two wires on the neg post)

The other end (away from the battery neg post) of the shunt takes all the negs from everything--including the battery to frame "ground"--

You might need a buss bar (using the inverter neg terminal as a buss helps) to collect some of those neg wires and then run a fat wire from the neg buss to the shunt. The short shunt bolts can only take a few stacked lugs before they won't reach to screw in.

The shunt should be mounted where ALL current out-of and into the battery is monitored. It does not matter where in the line it is mounted, as long as all current from/too the battery passes through it.

MEXICOWANDERER wrote:
Keep shunts, buss bars, fuses and breakers as far away from a flooded battery as possible.

Agree. All batteries (but especially flooded lead acid) give of vapor that will get to corrosion on most metals.

MEXICOWANDERER wrote:
The contact point to the shunt's metal should be mirror bright then a coating of NON PETROLEUM BASED sealer applied over-top.

While I would agree a silicone dielectric grease is probably best, but why the heavy emphasis on non-petroleum ?

MEXICOWANDERER wrote:
The shunt's milliamp wire terminals should be soldered.

Picking a nit, the metering device at the end of those wires is actually measuring millivolts. The amount of current passed is probably in the microamp range.