Electrical issues can stem from shorts, open circuits, over- and undervoltage.

Scenarios with are less common than undervoltage but are more likely to cause damage to components.

In a TV/motorhome an overvoltage in the DC vehicle system is likely associated with the failure of a voltage regulator.

On the “house DC power” side high voltages are due to the necessarily-higher charging voltage being applied to the house batteries. Trojan T-105 batteries, for example, are charged at 14.8v, floated at 13.2v, and equalized at 15.5v.¹⁾ These voltages may trip safety circuits in some devices and it is common to disconnect house wiring before equalizing.

In smaller applications it may be possible to run a DC-DC converter between the battery and the house wiring. This would allow the battery to run at charging voltages but provide house power at 12.7v or whatever level you prefer.

Undervoltage can result from low voltage at the source (like a battery is depleted) or through voltage drop through the connections.

• diagnosing voltage drop