Voltage meter question.

[JonSidneyB]

Let first see if I am using the right name. I am asking about something that will mesure the voltage of a battery.
Next question. how low of voltage can a common one measure and how accurate are they.
If I were to take two batteries of the same brand and age, and there voltage is the same. I take it that they are at this point the same and can be used togeter??? What if one of the batteries measured .7 volts and the other measures .9 volts, Can these batteries be used together???

 

[raggie33]

im no expert but i dont think a voltage meter will work for that since the battery wont be underload. but i may be very wrong

 

[CM]

You're looking for a multi-meter. There's a discussion here DMM Discussion

Voltage is not necessarily a good indication of the state of charge of a battery, and you should not mix batteries that are known to be different states of charge.

CM

 

[INRETECH]

You really can't determine the state of a battery without presenting it a load, a battery might read full voltage open circuit and then nearly dead when you apply a load if there is something wrong with the battery

 

[Doug Owen]

As others have said you generally need to put a load on a cell or battery to see what's up. This is not as tough as it sounds, however. Eveready lists the numbers for alkalines on their excellent site. For testing general use D, C, AA, and AAA cells they use ten ohms and reject cells under 1.1 Volts. For high current (motor drives and flash use per them) they use 1 Ohm and keep the same cutoff voltage. 250 ohms and 6.6 Volts is the test for 9 Volters, with 15 Ohms and the same voltage for the high current test.

Two watt resistors in those values are cheap and will convert your Volt meter in to a loaded cell tester.

Doug Owen

 

[INRETECH]

And remember, the resistors do get hot !