3 tons wrote:
Well, per your previous (after hooking up the inverter dc side cabling only - ac side not yet connected) and with the battery voltage initially reading 6v then rapidly dropping to 1 or 2 volts within 10 seconds dropping, that seems like a whole bunch of current going somewhere??
How much current does the victron read when doing this, and does this only occur when you hook up to the dc bussbar ??...(just trying to isolate this a bit).
Unfortunately, the Victron shunt does not give a reading when the voltage is at 1-2 volts (nor when the voltage is rapidly dropping from 6, 5, 4...) because the shunt requires some minimum voltage to operate, so it just turns off.
Yes, this problem only occurs when I hook up the DC bus bar AND the inverter simultaneously. With only the DC bus bar hooked up (and no inverter), everything looks and works normally. So when either the inverter or the DC bus bar are hooked up, all is good, but when both are hooked up something causes the voltage to drop to almost zero.
My understanding is that the negative DC bus bar is connected to the chassis for grounding, and the inverter/charger is also grounded to the chassis. Maybe that common ground is causing an issue.
Also, while the DC bus are is connected, as soon as I hook up the inverter, about a quarter of a second later I hear a click from inside the inverter, like a relay or switch is tripping. This could simply be the inverter recognizing that it has too low of voltage (requires minimum of ~10 volts to power on), or maybe it could be a relay that's diverting the power to ground/chassis.
Regardless, I still don't fundamentally understand what can cause voltage between battery terminals to temporarily drop to almost 0, and then have it return to normal 13V as soon as a wire is disconnected.
