I installed the Thornwave Powermon 5S shunt last season to provide a better gauge of battery capacity for the 200 AHr LiFePO batteries. Our 5.0 in 2021 was an early lithium build with the GoPower charge controller and a Victron DC-DC converter for the tow power. Realized quickly the GoPower charge state is not very useful for Lithium.
https://www.thornwave.com/collection...ted-500a-shunt
The Powermon 5S chosen for its bluetooth and memory over the Victron shunt without memory, and to save having to purchase a $$ Victron display unit. The Powermon phone app works very well although it's a bit of a time sink if you get caught watching what draws how many amps! Put in a Victron 100/20 charge controller to up charging yield, and it too has a nice phone app. Very useful when positioning an external panel.
Thornwave is now introducing a colour LCD display that will Bluetooth connect to the Powermon 5S shunt. I lucked into purchasing a beta model to assess, the production model should be available in a few weeks-months. The display provides real-time output of shunt parameters without needing to pull out your phone.
https://www.thornwave.com/collection...screen-display
It's a nice footprint for installation, and I believe it will fit in the overhead console just above the SeeLevel II display over the stove (5.0). The unit only requires a power connection supplying 8-65 VDC, and to be within Bluetooth range of the shunt. As others note the Thornwave shunt range is really good, able to connect from the tv cab usually.
The display is clear and bright and setup is very easy and logical, without need of using the manual. It includes a WiFi connection for software updates. The design includes power saving features like sleeping the display, also saves having to tape paper over it for sleep time. The manual is on the web page at the link.
I'm hoping to do the install or at least a shunt connection test in the next few weeks. Here in the frozen north our trailer is parked behind 3' of snow, and takes some planning to get in close enough to work (and perhaps snowshoes if the road is not plowed).
A word on shunts and Lithium battery charge state. Shunts act as a 'totalizer' type battery state monitor. That is, you set in the full charge capacity and the shunt counts charge leaving or entering the battery ('Coulombe counting') and maintains a running tally of state. It can be a very accurate gauge of charge state for a lithium, if the starting state is correct. It is the best approach for Lithium I've found, as the discharge voltage change is so small versus charge state (unlike lead acid types) to be a reliable and accurate metric. That's the main reason the GoPower controller was not much use.
(Totalizer is an aircraft term for a fuel gauge you set with pounds fuel from refueling, and then it meters consumption and counts down the fuel load. If you enter 10,000 lbs, but only uploaded 5,000 lbs the gauge will accurately count down until the engine flames out at 5,000 lbs remaining.)
Linear Mode
