Am now using the Victron Smart Shunt, available different sizes.
Works great. I particularly like the Bluetooth enabled app to monitor.
The SmartShunt is an all in one battery monitor, only without a display. Your phone acts as the display. The SmartShunt connects via Bluetooth to the...
www.victronenergy.com
Note
I also have the Renogy DCC50S charge controller with the Renogy BT2, a Bluetooth transceiver but Renogy app to monitor the controller seems under developed and is not as polished as Victron's app. If Victron ever comes out with a combo MPPT / DC to DC charge controller I would swap out the Renogy DCC50S for it as Victron has their act together (software / apps) regarding monitoring and controlling their device ecosystem.