Voltmeter showing different voltage readings for same battery.

[Shawn]

Why is it when I set the voltmeter to the type of battery it is it shows a different voltage than it does when I just set it to "voltage"?

 

[Sphexi]

Battery meters change the amount of "load" simulated depending on the setting. Higher voltage batteries get a slightly higher load placed on them, so as to make it more accurate. Straight voltmeters just measure voltage output, with no load, so it'll always look higher. Brand new AA batteries will have 1.8v, while "dead" ones will still show around 1.3v, even though it's lower with a load.

 

[Shawn]

That makes sense I think. I have a 9v I'm testing and it's showing up as 4.7v when set to voltage but only 1v when set to "9v". It's a rechargable battery but I'm guessing its past it's charge life?

 

[Sphexi]

Not necessarily, if it's rechargeable then the voltage will change depending on the charge. Put it in a charger for a few minutes, the voltage should go up.