Help identify this gizmo

[DanaMarlin]

Hi, does anyone know what those squiggly metal gizmos between the positive (red) battery cables on the lower right of this picture are? They appear to come directly from the battery banks and then are split out of the top to the battery isolator (left) and the breaker panel (above).

[kristjan]

It’s a dc shunt for current monitoring, to watch the charge going into each bank. The big black on on low right is to measure total discharge.

[DanaMarlin]

Originally Posted by kristjan

It’s a dc shunt for current monitoring, to watch the charge going into each bank. The big black on on low right is to measure total discharge.

Hi Kristjan,

Thank you for that. Sorry but the picture I uploaded turned out to be rotated 90deg CC, so my coordinates were a bit off. Do the shunts allow measurements in both directions - so for power going up to the breaker panel also? I am just wondering if the wiring looks correct having both lines out of the top of the shunts - one to the black isolator box and the other to the breaker panel.

[Zil]

The shunt is just a resistor. The meter attached is what can or not allow two way monitoring.
Shunts are usually on the negative side. Are you sure they are not some kind of fuse?

[Outlaw7]

They are shunts, the upper one has been bypassed. However that ground post has way too many wires to it. ABYC recommends no more than 4 terminals. It looks like they kept stacking them on and separating them with a nut.

[hellosailor]

They would be shunts, not fuses. The tip off is that there are two wires, of much lighter gauge, attached to each one. Those lighter wires are reading the voltage drop across the shunt, which is how amperage is measured.

Fuses would not have "extra" wiring like that. (Never say never, but...)

[a64pilot]

A shunt is a resistor, and those do look like resistors.
It would seem the Boat is ready for a third battery bank.

[boatpoker]

As Outlaw says ... that's nuts (paraphrased).

[GILow]

This is such a good example of the problem of time in boat electrics. That panel was pretty well thought out by the look of it, but over time things have been added and soon you have that terribly overcrowded negative post crammed in dangerously close to high current positive busses. If it were my boat I’d bite the bullet and break that negative consolidation out to its own bus bar at a safe distance from the rest of the circuit. The rest of it still looks pretty good and very flexible.