The SOC showing on my BMV-712 is accurate, if fluctuates based on voltage state of the battery as it should. However, my 120V Multiplus 3k almost always shows 100%, sometimes it drops to 98% at the most, but it is not accurate. All settings such as battery Ah capacity, voltage (24V) etc have all been verified in VEconnect. Any other ideas? And I have my VE network enabled on the BMV-712 so I thought it would be sharing it's voltage reading?
Hi from Colorado, @miami337.
Do you have some DC loads operating on your power project? If so...& if those loads are wired correctly through the metering shunt...that's battery depletion which the BMV can track but which the Multi cannot track.
The "state of charge" function in the Multi only works if all the system energy moves through the Multi...so you might as well disable this function again in VEconfig if you have DC loads. Ditto if you have solar energy connected through a DC charge controller because there's no way the Multi can know about that.
The most important aspects of state of charge monitoring do not rely on battery voltage but rather on the counting of energy packets which move into & out of the battery. This is sometimes called "coulomb counting" or amp-hour counting.
Check the Wikipedia article on State of Charge to learn more.
Sunny Days~
Hi back from Washington DC! Yes, this installation is on our catamaran, so we've got DC loads pulling from the battery bank all over the place. We've also got solar coming in, so it definitely sounds like I need to just disable the functionality in the Multi - I just thought the voltage was shared rather than "detected" when I had that network enabled. Thanks for the answer!
