Checking batteries
I assume a "DM-350a" is some kind of a digital multimeter. I Googled and found it might be a "A.W. Sperry DM350A 5 Function 17 Range Digital Multimeter" and looking at the ranges available on that meter, you can't really thest the battery "under load" the only reasonable way to test small batteries. the DC current only goes up to 200 milli amperes. A "C" or "D" size flashlight battery puts out 1 to 4 amps depending on conditions. That's 5 to 20 times the current readable by that meter. The volts on one of those batteries is probably 1.6 volts to 1.3 volts etc. If you live in the United States, I'd say go to Radio Shack and spend $5 to $15 and buy a battery tester like "Enercell Analog 9-Range Battery Checker, $14.99, Model 22-156, catalog # 22-156"
Then you and anyone in your family can read the instructions and test 8 or 9 different type batteries. Battery types: 1.5V button-cells, "AAA"/"N"/"AA"/"C"/"D", 6V, 9V, 12V, 15V and 22.5V..
This is not supposed to be an advertizement, and I have no interest in RadioShack,... but it's supposed to be instructional.
Small price, Good instruction to anyone who can read, and if anyone forgets, they can re-read. Testing a lot of batteries in a sitting goes very fast with these.
Differently, with the sperry, or any voltmeter, you'd have to select a resistor small enough to draw the current, and large enough not to overheat or burn, connect it and measure the loaded voltage drop, compare the voltage and current of the loaded battery, and compare it to that of a new battery, and a battery you might consider too weak for your application.. Voltage equals amps times resistance, and power equals amps squared times resistance... Really, buy a battery tester.
Regards --- GooseBay_Camper
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