Smartgauge Battery Monitor and Victron SmartShunt

[fearmhuir]

Hi All,
I have a question about battery monitoring.
Last year I replaced my battery bank with four FLA 6 V batteries, total capacity 450 Amp/hr.
I also installed a Victron shunt to monitor battery usage and voltage, together with 220 Watts of solar power, with a Victron controller.
The addition of the solar has been a real plus - even when cloudy I get something back.
For ages I have used a SmartGauge to monitor my battery, and it seems to work pretty well.
Since installing the Victron shunt, there is BIG divergence in the battery capacity readings between shunt and SmartGauge.
In the last month there was an instance of the SmartGauge showing 60% while the Victron shunt was showing 82%.
Using the SmartGauge on the last set of batteries, and not letting them get below 60% minimum (usually a lot less) the battery
bank lasted 8 years.
I have a suspicion that the SmartGauge doesn't account for low levels of solar input into the batteries, as on a cloudy day the SmartGauge reading falls
while the Victon level stays static.
My usage is marina on mains trickle charter for 6 months, then cruising with little mains usage for 6 months.
Any guidance on this?

 

[GEM43]

As I understand it the Smartgauge monitors only battery voltage and uses black magic (undisclosed tech) to determine battery SoC whereas the SmartShunt is an ah counter. I too found the Smartgauge always gave a downbeat assessment compared to an ah counter but the latter can be notoriously unreliable as a SoC monitor as they can get out of sync with the batteries. Alas, it’s a black art.

 

[fearmhuir]

As I understand it the Smartgauge monitors only battery voltage and uses black magic (undisclosed tech) to determine battery SoC whereas the SmartShunt is an ah counter. I too found the Smartgauge always gave a downbeat assessment compared to an ah counter but the latter can be notoriously unreliable as a SoC monitor as they can get out of sync with the batteries. Alas, it’s a black art.

Thanks Gem. Maye because I have used it for a number of years, I am inclined to believe the SmartGuage more than the shunt.
I will try at some stage, after a full charge on the mains charger, discharge for a while, and then with no load see how the battery voltage stands up.

 

[PaulRainbow]

The Smartshunt needs a full charge to sync the SOC reliably.

 

[fearmhuir]

The Smartshunt needs a full charge to sync the SOC reliably.

Yes, I was aware of that. I assumed that a full charge should synch both devices. However, when off mains for several days, with some motoring and solar, they are widely divergent. When I get back to a marina at the end of the summer, I will charge up fully, then disconnect the charger and the solar and see how they compare. Also then check battery voltage after 24 hours with zero load. Thanks to all!