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Old 11-03-2015, 04:26 PM   #25
leftybass209
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Join Date: Feb 2011
Location: Modesto, CA
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Re: Ammeter not working

Quote:
Originally Posted by ray_mcavoy View Post
Have you tested it at higher engine speeds? And if so, does the voltage go any higher?

A "12 volt" lead-acid battery won't start to charge until the voltage gets up into the 13.6 to 13.8 V range. Even then the charging rate will be rather low and probably won't register very high on the stock battery gauge. For a safe and reasonable rate of charge you'll want to see the alternator output in the 14.2 to 14.5 V range.

Your 13.56 / 13.5 V readings might simply be due to the fact that they were measured at idle speed. It's not uncommon for the alternator output to drop off at low rpm's. Try revving the engine up a little and see if the voltage increases.
Minimum voltage required to charge a lead-acid battery is 2.15 volts per cell. That equates to 12.9 volts required to start charging a standard car battery. If ANY of the 6 cells are not being charged at the minimum 2.15 volts, NONE of the cells will charge. A charge, is a charge, is a charge, no matter if it's little, or big. It is generally accepted however, to charge a vehicle battery at a higher rate, because it induces the charge more quickly.

In your case, the difference between the charging rate and the battery voltage isn't much, so you shouldn't expect to see hardly anything on your gauge.

A properly set up charging system with a functioning gauge really doesn't register much in regards to needle movement because the source voltage (battery) and alternator output should be as little as possible to maintain the battery charge. Of course, added electrical components can change the demands.

This is the reason I use a voltage gauge behind the stock amp faceplate. My amp gauge never visually indicated anything to me at a glance.

Just because your gauge used to work properly, doesn't mean it works now. It could have been on it's way out before and the changes you made pushed it over the edge.
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