Proper Alt/Battery Charge Gage Needle Position

I purchased new battery last July and I suspect that it faulty, however I’d like to know what position the needle is on your alt/battery gage on the dash. I replaced the battery temporarily with another I had lying around, and everthing seems to be working fine electrically in terms of lights, starting, etc, but I noticed that the needle for the alt/battery gage seems to be slowly dipping below the middle line on the gage. I swear it was right on the line up until recently, but today I noticed that it was below that line, even while driving on the Hwy. I was in my daughters 2011 Tundra yesterday, and the needle was slightly above that middle line. I just checked the voltage at the battery at engine idle with my Fluke residential meter (no decimal reading), and it was showing 13V. Will need to dig into it more tomorrow with my other Fluke meter, but was curious as to what others see on their alt/battery gage as far as where the needle typically rests.

 

Mine was always a little left and it was fine. At some point I installed an AGM battery and installed this fuse to increase the charging volts, and now it's a little right and also fine.

 

Same. It took me too long to discover this mod. No regertz.

 

I installed something like this and get a more accurate reading of 13.4-13.6 when charging.

$8 Car Charger USB C Car Adapter, 4 Port USB Car Charger with Voltage Display PD 3.0 & QC 3.0 Car Phone Charger Cigarette Lighter USB Charger Adapter Fast Charging for iPhone,Samsung,iPad & Phone Tablets

https://www.amazon.com/dp/B0C9DLDN19

 

Damn! Read some of the Amazon specific reviews for Tundras and Toyotas. What does it do actually, or should I ask how does changing a fuse increase alt output voltage?

 

IDK but I know my voltmeter was always in the 12s and since I swapped the fuse I'm always in the 14s and I don't notice it feeling like it's testicals are in a pinch as much. FWIW I have 4 12s and my lights flicker when boom boom happens.

 

Look up the voltage booster mod and the GM diode mod threads. They show how to increase the charging up to 14.4
Really needed if you have an AGM battery

 

Guess I’ll have read up on this mod. Just checked the battery at idle with my other Fluke meter, and it read 13.5V. Seems a bit low to me as IIRC my Lexus LX450 is usually between 13.7V and 14.2V as I have an OBD2 reader permanently hooked up. The battery I purchased last fall is a CarQuest Diehard Gold which according to the interweebs is an AGM type. It also has a 5/5 review. I’m wondering if it crapped out now due to this “low” voltage charging?

 

I have an AGM and bought the Singer Mod. Just have not installed it yet. I put a Battery Tender on it each weekend until I get around to the mod.
Check your battery charger and make sure it can do an AGM battery. Use that until you get the device to raise your voltage.

 

Alternator voltage is not a single constant. As your battery is nearing a state of full charge, the voltage output from the regulated alternator does gradually drop the charge voltage. Charge voltage also varies according to temperature, higher when cold, lower when warm.

 

I guess the question is - is there really a problem with the stk charging system, or is this just a “wanna be feel good” mod?

 

I just ordered this fuse. Should be delivered tomorrow from Amazon. Where exactly in the fuse box does this go?

 

I don't have technical data like I think you'd prefer but I have this to offer....

I have 4 12s and a few amps.
I do have the big 3/4 upgrade done.
I had shop run an alternator test and it was OK.
I even popped in an Optima battery and it was the same.

Prior to GM diode thing the lights in the truck would dim really bad when bass hit, always have a weak start, and constantly be in the 12 volt range as the amps would use the alternator and prevent it from charging up the battery like it should bc I don't make long trips just short runs.

I don't like battery caps so I was going to run 2 batteries but tried the GM fuse first due to it being cheap and easy and have not looked back. It's literally just changing a fuse.

I know it's not apples to apples bc I have an audio setup that's draining the system but in my unprofessional opinion the OEM charging system underperforms just a little and it's amplified when you're amplified.

 

I’ll order the fuse and see if makes a difference.