Dual shunts dilemma?

[Boxster1971]

I'm completing the design of a battery and inverter upgrade on my 2013 Airstream Interstate. Last year I upgraded the solar to 400 watts with a Blue Sky SB2512i(X)-HV controller and IPN-ProRemote. This remote uses a standard 500 Amp shunt to monitor current going in and out of the batteries.

My new inverter/charger choice is a Magnum MS2000. To get optimum charging of the four Lifeline GPL-4CT batteries I plan to install I'll need to use the Magnum ME-ARC or ME-RC remote with the ME-BMK Battery Monitor Kit that includes a 500 Amp shunt to monitor battery current.

So I'll end up with two current monitoring shunts. My first thought was I could use one shunt to supply a signal to the Blue Sky remote and the Magnum battery monitor. But I'm not sure this will work as the parallel hookup to the shunt would likely cause problems. Alternatively I could just place the two shunts in series to feed both the Blue Sky and Magnum. This seems like over kill. I've seen some installations that use one shunt to monitor the bulk current to/from the batteries for the inverter/charger and a second shunt to monitor just the solar charging.

Has anyone dealt with a dual shunt installation?

-- Mike
2013 Airstream Interstate Lounge EXT on 2012 Sprinter 3500 170Ext

[avanti]

I don't see why feeding one shunt to two devices would cause any problems (assuming they are expecting the same kind of shunt). They are just measuring voltage drop. If the devices have high-impedience inputs (as they should), they should work fine.

If you do use two in series (which should also work), be sure the second device is reading voltage drop only across the second shunt--not both of them.

[booster]

We have been running our Trimetric and the Blue Sky controller off a single shunt for several years without issue. Both Trimetric and Blue Sky said it was fine. We intend to do both the Blue Sky and Magnum off of one shunt in the new system.

[Boxster1971]

Great -- thanks guys for the input. I'll use one shunt to supply the voltage drop to both the Blue Sky and the Magnum. Should prove interesting to see how their reading compare.