The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 47-55.1 Battery charging issues

mr48chev · 01-20-2021, 01:17 AM

You do have a multi meter or volt meter?
With a meter set on DC volts connected to the battery you should show about 7.1 volts with the engine speeded up a bit. Generators normally do not charge very much at an idle and some don't charge at all until you get the rpm up.

As far as that goes, if the needle on the ammeter shows charge when you are going down the road that should be good and move on to the next thing.

Next thing: Like going to the Indian health medical clinic that I go to quite often when trouble shooting the first issue you think of is what you look for all day long and you miss the reall issue.
Simply:

Does it show a charge on the ammeter or the multimter you connect to the battery when you rev the engine up a a bit Yes--- NO _______

Have you had the battery tested. I don't give a rip if you bought it this morning if you have issues has the battery been tested?

What is the condition of the starter? The starter may be dragging or have worn brushes. Brushes, bushings and or bearings for the starter don't cost much and aren't that hard to change.

What size are the battery cables? Those skinny cables sold at Autozne or O'Reilly's or other parts houses won't carry the amps that 6 volts is able to push very easy. When I was teaching autoshop I used to use an old Mopar training film to teach Volts, amps and Ohms. This was from the early 50's but it explained it in very basic down to earth terms. Think water pump and water pipe.hose. You can push a pretty good volume of water though a 3/4 inch pipe and hose with a small pump but the same small pump won't move near as much water though 1/2 inch pipe and hose. The pressure at the pump will be good but the flow is restricted. That is why you need larger cables with 6 volts than 12 volts. you don't have the pressure to push the amps though skinny cable.

Test and check before spending money. when it cranks slow get out and start feeling cables and see if one is hot to the touch. That means extra resistance an you need to trace the resistance down.

Last, don't be afraid to ask questions. That includes sending me or one of the others you feel has the right answer a pm if you feel the need.,

01-20-2021, 01:17 AM	#12
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,301	Re: Battery charging issues You do have a multi meter or volt meter? With a meter set on DC volts connected to the battery you should show about 7.1 volts with the engine speeded up a bit. Generators normally do not charge very much at an idle and some don't charge at all until you get the rpm up. As far as that goes, if the needle on the ammeter shows charge when you are going down the road that should be good and move on to the next thing. Next thing: Like going to the Indian health medical clinic that I go to quite often when trouble shooting the first issue you think of is what you look for all day long and you miss the reall issue. Simply: Does it show a charge on the ammeter or the multimter you connect to the battery when you rev the engine up a a bit Yes--- NO _______ Have you had the battery tested. I don't give a rip if you bought it this morning if you have issues has the battery been tested? What is the condition of the starter? The starter may be dragging or have worn brushes. Brushes, bushings and or bearings for the starter don't cost much and aren't that hard to change. What size are the battery cables? Those skinny cables sold at Autozne or O'Reilly's or other parts houses won't carry the amps that 6 volts is able to push very easy. When I was teaching autoshop I used to use an old Mopar training film to teach Volts, amps and Ohms. This was from the early 50's but it explained it in very basic down to earth terms. Think water pump and water pipe.hose. You can push a pretty good volume of water though a 3/4 inch pipe and hose with a small pump but the same small pump won't move near as much water though 1/2 inch pipe and hose. The pressure at the pump will be good but the flow is restricted. That is why you need larger cables with 6 volts than 12 volts. you don't have the pressure to push the amps though skinny cable. Test and check before spending money. when it cranks slow get out and start feeling cables and see if one is hot to the touch. That means extra resistance an you need to trace the resistance down. Last, don't be afraid to ask questions. That includes sending me or one of the others you feel has the right answer a pm if you feel the need., __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.