In a message dated 10/30/2004 12:19:16 PM Eastern Standard Time, dvanhorn@dvanhorn.org writes: How do you test a battery with a meter? > > >Should a battery have a certain amount of amps? > >I have a big lead acid car type battery that seems to be >not up to the task, But, is the testing procedure the >same for flashlight batteries too? > >My big lead acid battery doesn't seem to have any amps. >Volts are OK. But it won't turn the engine. It is almost impossible to test a battery with just a multi-meter. In order to properly test for the current output and proper voltage under load you must have some way to load the battery for the test. If the battery is in a car you can, for instance, turn on the headlights and see how much voltage drop you have while they are on. If the battery shows no voltage drop it is either a "perfect" battery, which is not likely or, it isn't being loaded. Of course if the lights don't come on when you turn them on but the voltage stays up and ok on the battery there is a problem in the circuit. However, if there is a substantial voltage drop, say below 11 volts or so then you may have a problem with the battery. Regular batteries such as those for a flashlight also must be tested under load to get an accurate result. Radio Shack used to sell a small battery tester that can test D, C, AA, AAA, 9V, and button batteries. I don't know if they still sell it though. I have one and it has worked great for several years. I am sure you can fine a tester from Jameco or some other supplier. Randy Abernathy 4626 Old Stilesboro Road NW Acworth, GA 30101-4066 Phone / Fax: 770-974-5295 E-mail: cnc002@aol.com I furnish technical support, repair, and other related services for your industrial woodworking machinery. My background as Senior Service Engineer for the SCMI Group for nearly fifteen years with factory training, combines with my extensive background in electronics, mechanics, pneumatics, electrical and CNC machinery to offer you needed support for your machinery. _______________________________________________ http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist