Since I picked up a new multimeter to replace my Craftsman 82141 (fuses are only sold in a kit with no specifics on what the size is) with a RadioShack 2200087 46 range meter, since it was on sale since the store here is closing. It uses AA batteries rather then a 9V battery, which is nice for convenience. Since I had Lithium batteries that were close, that's what I used in the meter. They were also the closest AA I had to hand at the time (TL;DR: I gave some of mine to someone, and they bought me a 4 pack to pay me back). Since I didn't pay for them, it doesn't hurt to try
. When I have to buy more, my tone is going to be different based on the results of my Lithium runtime testing (how low do the batteries have to go for the readings to become unstable or lose accuracy?) The low battery indicator comes up at 2.5V (more on this later in the post).
I've looked into the voltages for each type of battery. Alkaline is 1.5V. The total voltage is 3V (1.5x2). NiMh batteries are ~2.4V (1.2x2).
Once you get to the Lithium cells, it's 1.8V/cell, which adds up to 3.6V (1.8x2). This is only a .6V increase, so not very substantial. I do not think I will get much extra runtime out of Lithium, based on those numbers. Maybe I will see an improvement, but I'm not holding my breath.
The other thing I am confused about this meter on is why the low battery voltage of 2.5V (listed in the manual) and provided as an attachment. To me, 2.5V seems premature and seems VERY conservative. Maybe this is because of the data logging ASIC, though. If anyone can explain the idea behind such a early battery warning, I'm interested in why they set it so high. I may very well be missing something.
Do Lithium batteries make a appreciable enough difference in runtime to justify the extra cost (it's ~$11-16 for 4 batteries)? The only pitfall I can see is the meter having the low battery indicator come up significantly early (or not showing up at all), relative to how long it will actually take with Alkaline or NiMh cells. All that really means is I really need to rely on accuracy to judge the health of the batteries, which I already do anyway. I will also need to carry around extra batteries (again, I already do this). If the cost doesn't make sense, I'm just going to buy Alkaline or NiMh batteries.