Boothbay wrote:
I bought a radio shack multitester to check my batteries, primarily my
laptop batteries. First on my old dead battery of Toshiba laptop, they
had a positive and negative mark shown..so it was easy to check it out
with the tester. But I bought it to check my Dell battery that lasted 1
year to the day of the end of my warranty. Fortunately, i did get a
refurbished one in time. Disappointed that it only lasted a year and I
had only used it a total of maybe 10 hours with the battery on my last
vacation...10 hours in 1 year and poof it went. The battery does not
have a pos and neg shown like the toshiba one..so I cannot test it that
way. In the meantime, I was trying to check some AA and AAA batteries
that I had and was able to understand on how to test them..but I do not
know how to interpret the readings I used the ACV side with it set at
15. I really don't know what does numbers mean. The manual is a joke,
at least for those of us that have no experience. The line moved a
little to the right where it seem to end a couple of notches on that ac
15v scale. It read the same for the new battery as well, so what is it
telling me that its a 1.5v battery? How does one know if the battery is
weak or whatever? Does anyone know of a web site that can tell me what
those readings represent? I did a search in google but nothing came to
what I was hoping for.

As others have already said, you need to use the DC scale.

You need to do some reading about how battery voltages change with state
of charge. Lots of those type sites on the web. Something like this
one that I found with a quick look:

http://www.uoguelph.ca/~antoon/hobby/techbat.htm

Your Dell battery is a set of several hooked in series. The voltage
will be approximately 1.2 times the number of batteries. For example a
15 cell NICAD battery will measure about 18 volts (1.2 x 15). If it
suddenly drops by about 1.2 volts it means that one of the cells has
shorted.