House battery voltage under draw?
I have a new (to me motor home) and an upgrade from my old one. In my old RV, I had to check the house battery voltage manually. With the new rv, I have a switch on the wall. However, when I check t...
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Ideally, the voltmeter would be connected right to battery terminals, not sharing a circuit with other devices loading the DC system.
Other loads on the circuit will have a voltmeter read lower than if it were connected right to the battery terminals.
HOw much lower depends on the size of the load and the length of the circuit and the size of the wire sharing that load.
The battery itself, its capacity and intended use, will have a lot to do with voltage under load.
I've noticed brand new batteries might appear to hold poor voltage on the very first cycle as they are discharged, but improve after the first full recharge.
I have not been impressed with a brand new 12v group 31 Crown1 AGM, but it does not even have a CCA spec, and claims to be optimized for deep cycle use.
Such a battery would have voltage drop more than an equal capacity battery intended for both engine starting, and deep cycling.
Other loads on the circuit will have a voltmeter read lower than if it were connected right to the battery terminals.
HOw much lower depends on the size of the load and the length of the circuit and the size of the wire sharing that load.
The battery itself, its capacity and intended use, will have a lot to do with voltage under load.
I've noticed brand new batteries might appear to hold poor voltage on the very first cycle as they are discharged, but improve after the first full recharge.
I have not been impressed with a brand new 12v group 31 Crown1 AGM, but it does not even have a CCA spec, and claims to be optimized for deep cycle use.
Such a battery would have voltage drop more than an equal capacity battery intended for both engine starting, and deep cycling.
