what voltage is your alternator giving you?

C6H12O6

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What diode did you use? Pic please? Good stuff.
Amazon product

You have to file the side down a bit to get it to fit, and it's a diode, so it only flows one direction, so you have to be careful to insert in the correct direction in the fuse spot. No biggie. Just check to make sure it's charging when you're done.

I did get a little impatient with filing the side plastic down and exposed a bit of the metal inside, but it works fine. Probably the same as the one posted above, but a lot cheaper.
 
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What charging voltage do I need for group 27F AAA calcium-calcium battery?
 

94SRUNNER

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Charging voltage from the vehicle voltage gauge or from a charger?

How are you measuring/monitoring voltage? Factory gauge? ScanGauge or alternate OBDII reader?

When your truck is warmed up and running, you should see voltage greater than ~13.3V to ~14.1V.
 
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Charging voltage from the vehicle voltage gauge or from a charger?

How are you measuring/monitoring voltage? Factory gauge? ScanGauge or alternate OBDII reader?

When your truck is warmed up and running, you should see voltage greater than ~13.3V to ~14.1V.
I am using a calibrated Fluke 189 DVMM… stock I get 14.27V at cold startup, and as the engine warms, the voltage drops to 13.66V. All loads turned off.

I understand that calcium-calcium batteries require at least 14.4V to charge. Using the diode trick, higher initial charging voltages would reduce or eliminate electrolyte stratification, and as the charging voltage reduces upon warmup, a minimum of 14.4V will maintain the battery properly. With the stock charging voltages, my digital Schumacher battery charger shows that this battery is not increasing it’s charge percentage.

I have heard good things about the diode trick… but only as relates to AGM or calcium-calcium batteries. Higher charging voltages can and will damage a standard lead-acid battery.

Any informed experience with this issue would be appreciated.
 
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I am using a calibrated Fluke 189 DVMM… stock I get 14.27V at cold startup, and as the engine warms, the voltage drops to 13.66V. All loads turned off.

I understand that calcium-calcium batteries require at least 14.4V to charge. Using the diode trick, higher initial charging voltages would reduce or eliminate electrolyte stratification, and as the charging voltage reduces upon warmup, a minimum of 14.4V will maintain the battery properly. With the stock charging voltages, my digital Schumacher battery charger shows that this battery is not increasing it’s charge percentage.

I have heard good things about the diode trick… but only as relates to AGM or calcium-calcium batteries. Higher charging voltages can and will damage a standard lead-acid battery.

Any informed experience with this issue would be appreciated.
I have the same readings and I don't believe this is any cause for concern. 14.4V pretty steady until truck is warm and then it levels out around 13.6-13.8... I'm running this battery here. Going on 5 years and it hasn't ever had any issues with the stock 100 series alternator. Every few weeks I'll plug into a battery tender and get it all topped off.
 

e9999

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^ ^^ why are you guys sounding like it's the engine being warmed up that makes the voltage go down? Yes, there may be a small effect if the idle speed changes with warmup, but otherwise I can't see that the temperature of the engine has much to do with the voltage regulation. What am I missing?
 
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^ ^^ why are you guys sounding like it's the engine being warmed up that makes the voltage go down? Yes, there may be a small effect if the idle speed changes with warmup, but otherwise I can't see that the temperature of the engine has much to do with the voltage regulation. What am I missing?
I can't say it's normal and some may have other experiences but before I am up to operating temp my readings are 14+ but once up to operating temp it always is down in the 13.6-13.8 range. I've never had any battery issues and she always starts so I just summed it up to normal.

Is the cruiser smart enough to regulate the voltage down a bit unless it's under a heavy load and needs more juice?
 
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The ECU reduces alternator voltage when engine approaches operating temperature. Part of Mr. T’s programming to increase MPG save polar bears.
 
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Hey so FYI, I had bad alternator this summer. When the car was running it was giving me 12.7 v so clearly the alternator was bad. I swapped my 100amp Alternator with a 130amp one and switch out the 4 pins.. Since then my car essentially idles when fully warmed up at 13.42V.

But my problem is my car sat outside for a little bit (2 months or so) and when I went to start the battery it didnt start... It was a new interstate 27F battery from Costco. I am wondering is the 13.42V are enough? or am I dealing with a DOA battery that I need to swap out?

I have not run any battery tests but I will do that pretty soon. and report back what I find out.
 
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Hey so FYI, I had bad alternator this summer. When the car was running it was giving me 12.7 v so clearly the alternator was bad. I swapped my 100amp Alternator with a 130amp one and switch out the 4 pins.. Since then my car essentially idles when fully warmed up at 13.42V.

But my problem is my car sat outside for a little bit (2 months or so) and when I went to start the battery it didnt start... It was a new interstate 27F battery from Costco. I am wondering is the 13.42V are enough? or am I dealing with a DOA battery that I need to swap out?

I have not run any battery tests but I will do that pretty soon. and report back what I find out.
2 months is long enough for a battery to go flat if you have the slightest little drain somewhere, maybe your clock.
 
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What is the voltage level from the battery? I found this information from a Lexus (not LX470) owner manual.

24F_battery.JPG
 
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2 months is long enough for a battery to go flat if you have the slightest little drain somewhere, maybe your clock.

Yes it could very well be a parasitic drain that I need to troubleshoot as well.. right now I am recharging the drained battery with a battery charger and see where this goes from there..

Any good videos you folks recommend on tracking parasitic drains??

I think iirc the videos will recommend just monitoring the battery voltage with a Multimeter while engine off an and start removing fuses and seeing if the voltage changes.
 
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Yes it could very well be a parasitic drain that I need to troubleshoot as well.. right now I am recharging the drained battery with a battery charger and see where this goes from there..

Any good videos you folks recommend on tracking parasitic drains??

I think iirc the videos will recommend just monitoring the battery voltage with a Multimeter while engine off an and start removing fuses and seeing if the voltage changes.
if I am not using the car for any period longer than a few days, I chuck the smart charger on. Everything still connected, I like the ctek. need good healthy batteries for remote.
If longer than a month, for sure, I pull the earth cable. And ctek.
 
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if I am not using the car for any period longer than a few days, I chuck the smart charger on. Everything still connected, I like the ctek. need good healthy batteries for remote.
If longer than a month, for sure, I pull the earth cable. And ctek.
it is no fun and takes much time to find a little drain somewhere. easier to pull the earth, or better the battery if suspicious when there is periods of no use.
 

OEMGUY0720

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Amazon product

You have to file the side down a bit to get it to fit, and it's a diode, so it only flows one direction, so you have to be careful to insert in the correct direction in the fuse spot. No biggie. Just check to make sure it's charging when you're done.

I did get a little impatient with filing the side plastic down and exposed a bit of the metal inside, but it works fine. Probably the same as the one posted above, but a lot cheaper.

Using this diode mod, this is what I’m getting on idle and cruising @ 55°F outside air temperature:
D62623D8-E013-4FE0-8ECB-580D905CBCD2.jpeg
 

e9999

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If you're wondering about parasitic drain, it is as easy as turning everything off and putting a clamp DC meter on a battery cable to measure the level of drain. Although if it's very small, inexpensive meters won't be very accurate. But then again, if it's very small, no need to worry about it. From memory, I'm thinking that 100mA and less is fairly typical (not sure). If you lose 100mA your typical starter battery of 100Ah would be fully discharged around 1000 hrs in first approximation. That is something like 1 to 2 months, so yea.

As to the 13.4, that seems on the lower side when fully-charged yet probably OK, and if you go to the 14.4 range right after starting and the voltage slowly decreases from there, you are probably fine. But if you are never getting much above 13.4 and never up to well over 14V at first, that is not normal I would think.
 

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