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buy a digital multimeter instead...
you'll find this a lot more useful..plus you can always load down the batteries by switching on your lights and stereo, etc.
you'll find this a lot more useful..plus you can always load down the batteries by switching on your lights and stereo, etc.
Depends on what you saw
Battery makers will only make warranty tests based on a LOAD TEST, not on a multimeter. The results tell you different things. If you saw a load teste for $29, and it provides enough load to test your batteries without burning up, sure, it is a valuable tool. The real question for any battery is not "what's the voltage" but "what's the voltage under load" and for a car-sized battery, they may typically throw a thousand watt load on it, to simulate a starter motor. You won't get that from headlights and such.
Battery makers will only make warranty tests based on a LOAD TEST, not on a multimeter. The results tell you different things. If you saw a load teste for $29, and it provides enough load to test your batteries without burning up, sure, it is a valuable tool. The real question for any battery is not "what's the voltage" but "what's the voltage under load" and for a car-sized battery, they may typically throw a thousand watt load on it, to simulate a starter motor. You won't get that from headlights and such.
load test
I don't know about the cheap load testers but you can do a reasonable load test with the multi meter using your starter as the load. Almost any of the electrical how to books has the procedure. Can't remember the specifics, but i think its something like if you crank the engine for 10 to 15 seconds and the battery voltage drops below 9.7 volts you have a bad battery. Remember to disable the start system and drain your water lift muffler when cranking but not starting the engine.
I don't know about the cheap load testers but you can do a reasonable load test with the multi meter using your starter as the load. Almost any of the electrical how to books has the procedure. Can't remember the specifics, but i think its something like if you crank the engine for 10 to 15 seconds and the battery voltage drops below 9.7 volts you have a bad battery. Remember to disable the start system and drain your water lift muffler when cranking but not starting the engine.
Load testing House batteries
I was more interested in load testing the house batteries, so with a volt meter I could always "load" each house battery individually with the inverter and watch the voltage. I'll have to brush up on my battery load testing homework. Thanks. Bob
I was more interested in load testing the house batteries, so with a volt meter I could always "load" each house battery individually with the inverter and watch the voltage. I'll have to brush up on my battery load testing homework. Thanks. Bob
If you really wat to load the batteries...
crank the engine and watch a DC voltmeter scale on a multimeter.
crank the engine and watch a DC voltmeter scale on a multimeter.
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