With the two fuses for power windows, clock and fuse off, and 6-12 volt converter box disconnected, the test light comes on and I still read .13mA
Bones, analog voltage meters are more than accurate enough for automotive use. Most people, it is true don't have low ranging analog meters. That isn't quite the same thing. And for some purposes - analog gauges are MUCH preferred or even necessary. For most of the cars on topic here, remember they were designed and engineered with analog equipment and also the voltage specifications listed in the manual should be considered in that light as well. Modern stuff has a different input impedance, sometimes it matters. Those fancy-pants Digital electronics don't always get along or play well with DC generators, old school voltage regulators, solid core spark plug wires etc.
Do you have a modern stereo with a hot wire for memory function? Do you have a cell phone charger plugged into a dash hole? There is no way a 13 milliamp draw will pull a battery dead in a few days. I’m beginning to question your meter. I would also like to know how to test a battery by “running a current through it”. I believe what you say, I really think they are full of shit. What happened to using a good old fashioned carbon pile tester. Like a VAT-40? We have the new fancy pants electronic battery testers at work for the kids and dumbshits, but we also have a carbon pile too and it’s never steered me wrong. By the way, the store will always tell you the battery they sold you is good. Sent from my iPhone using The H.A.M.B. mobile app
Truck64, they are easier to see/ read after you get a certain age! But I do like analog for rapid voltage variations, needed in some test, such as determining if the points are working and such. I have a lot of analog meters, but in my old age, I tend to grab digital. Just me! Bones
Put that light tester back in, and start pulling fuses. One of them should put the light out. If it doesn't, something's hooked straight up (unfused), or start looking elsewhere, maybe your regulator/charging circuit.
Agreed. I would test it using a more or less known low current (like the current feeding a small light bulb) to verify that the reading is resonable close to reality.
As you know, a load test proper requires the battery to be charged up both before and after the test, and this takes time. Way up yonder in post #29 I took the time to explain a similar test using the engine starter but I never heard anything back.
That is my plan today, though I have done it befor I had the battery tested. This time I’m going to disconnect the fuse box from the starter, cut all fuse power and test the amp.
I’ll also test volts and amps this morning before I do anything else. I left the battery off all night
You have to think OReilly might give the new battery a pass so they don't have to make good on the guarantee. Get a second opinion on battery test at NAPA store. Phil
Did we ever find out what kind of charging system the car has? Anyways.... a clock in an old car will only draw power when it winds, which is every minute or two. It draws a fair amount of current, enough to make a decent little spark, but only for a very short time. A 130 micro amp draw that you are seeing all the time could be from any electronic device you might have plugged in, or it could be from corrosion somewhere providing a resistive ground path. Or possibly a leaking component in a voltage regulator or filter capacitor or something. Disconnecting wires and fuses might help you find where it is. But the battery is still junk, you need a new one. If you get tired of hassling with warranty crap, just buy a new cheap battery from Walmart, and forget the warranty. Your car will probably work fine.
So I’m going to not do anything else till tomorrow morning. I’m very curious what the voltage will be.
That .07 of a volt drop doesn’t mean it’s a bad battery, it could be due to different temperature of the battery or the charge” settling down”. Might check the voltage in the evening again . Checking again tomorrow morning should tell you something. Bones
12.26 volts is pretty damn low, for a battery that is supposed to have been charged. Also, just for fun, disconnect the battery cable, then disconnect the fat wire from the altenator, keep it protected from shorting. Then do the current draw test again, with the alternator disconnected.
A battery that's just been charged can't be measured accurately, it has a "surface charge". With the engine off, turn the headlights on for five (5) minutes. Shut them off and wait at least ten (10) minutes and then measure. That battery should measure 12.65 volts at 77° F. That's a fully charged conventional lead-acid battery. 12.2 or 12.3 is maybe 50% discharged, depending on the temperature. It doesn't mean it won't start the engine but it doesn't have the reserve current it should have.
Just tested volts....lower reading, at 10:39am it was 12.26v. And there was no spark at all when I connected neg
It’s gotta be the battery right? There’s no point in pulling fuses again? .13milliamp shouldn’t kill a battery over two days of sitting? Correct me if I’m wrong. If it’s 11v by Monday morning I’m trashing it
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