X2 Battery Already Dead

Can someone explain what a diode is doing to improve charge voltage?

Voltage Boosters
These devices work by effectively tricking the alternator voltage regulator into seeing less voltage than it is actually producing thereby causing it to compensate to produce more. So in a simple example if you want to increase the voltage by 0.5v, you cause an artificial 0.5v loss on what the voltage regulator detects and it compensates by raising the voltage an additional 0.5v giving you a net gain.

The Alt-S Circuit The Alt-S circuit is the circuit used by the voltage regulator to monitor voltage at the battery and adjust accordingly. You can read more on the Toyota Alt-S circuit here. This simple mod is only works in vehicles where the Alt-S circuit exists for the voltage regulator to control the voltage.

In some newer vehicles like the 2016+ Tacomas, the voltage is regulated by the ECU, meaning no voltage regulator Alt-S circuit to spoof. The ECU can be reprogramed for 3rd Gen using OV Tune and likely others, see post #3821 here for details.
 
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@ThatNavyGuy . IMO, this isn’t a charging voltage thing. I’ve been using agm batteries in vehicles as old as 2006 with no premature failures and no voltage mods. If the vehicle doesn’t have a drain issue, im thinking it’s a defective battery and a warranty opportunity. Don’t beat yourself or write off the premium product either. IMO you didn’t “miss something“ by not knowing. On one hand, AGMs enjoy a *slightly* higher *optimum* voltage for charging. On the other, its a small difference, and vehicle charging systems are still crude with noisy power all over the place, so it just takes a slightly longer drive to reach a full charge, which seldom happens anyway with modern charging systems. Don’t beat yourself up - see if you can get an exchange and see how that goes!
 
My first group 27 northstar battery lasted 6 years and 1200.deep cycle and thousands.of engine starts.
Easily the most.impressive battery Ive ever cycled to death and.that is many.

My current group 31 northstaR has been treaTed waY better. Charged ro.truly full muxh more, less deep cycles few.partial state of charge cyxles and overall, much less Impressive performance. I' ll be surprised if it lasts 5 years and 900 deep cycles.

I think northstar pulled an Optima,... developed a good.reputation , then cashed out.

Hopefully odyssey still cares.
 
When I bought my X2Power battery 2 years ago, it included a 5 year full replacement warranty. But now I see they have a 4 year warranty. And the price has skyrocketed.
 
@ThatNavyGuy . IMO, this isn’t a charging voltage thing. I’ve been using agm batteries in vehicles as old as 2006 with no premature failures and no voltage mods. If the vehicle doesn’t have a drain issue, im thinking it’s a defective battery and a warranty opportunity. Don’t beat yourself or write off the premium product either. IMO you didn’t “miss something“ by not knowing. On one hand, AGMs enjoy a *slightly* higher *optimum* voltage for charging. On the other, its a small difference, and vehicle charging systems are still crude with noisy power all over the place, so it just takes a slightly longer drive to reach a full charge, which seldom happens anyway with modern charging systems. Don’t beat yourself up - see if you can get an exchange and see how that goes!
Talking to you and to some others I know has me leaning towards this. Even if the charging system isn’t delivering an optimal charge (for an AGM) this battery should not have failed in less than 4 months.
 
Until you do more testing, you don't know the problem.

You said the voltmeter on the dash indicated something over 14v, but I don't see where you got a specific number. Is it even accurate? Unless I missed it, you haven't tested with a standalone volt meter.

You are guessing at a current draw. Sure, maybe you can tell there is no light on. What about the various computers in the car. Does it ever fully go to it's lowest power draw? Assuming the charging system is good, you may need to do some other testing.

Maybe take that VMM and test the voltage after the vehicle sits overnight. First with the battery connected and then with the negative cable disconnected.

If the voltage drops while disconnected, yes, the battery is rapidly self-charging.

If it only drops when connected, you have a current draw when the vehicle is off and you need to find out what circuit it is.

I don't see enough data to convict or acquit any component at this time.
 
Until you do more testing, you don't know the problem.

You said the voltmeter on the dash indicated something over 14v, but I don't see where you got a specific number. Is it even accurate? Unless I missed it, you haven't tested with a standalone volt meter.

You are guessing at a current draw. Sure, maybe you can tell there is no light on. What about the various computers in the car. Does it ever fully go to it's lowest power draw? Assuming the charging system is good, you may need to do some other testing.

Maybe take that VMM and test the voltage after the vehicle sits overnight. First with the battery connected and then with the negative cable disconnected.

If the voltage drops while disconnected, yes, the battery is rapidly self-charging.

If it only drops when connected, you have a current draw when the vehicle is off and you need to find out what circuit it is.

I don't see enough data to convict or acquit any component at this time.
Took your suggestions.

Engine off, no start since yesterday afternoon 12.0V
Engine on 14.9V
No voltage drop connected or disconnected stayed a steady 12.0V after 10 minutes.
Truck performed flawlessly the day prior to the extremely cold temperatures. No lights left on or anything other than routine operation and shutdown. The only variable was the low temp.
 
Took your suggestions.

Engine off, no start since yesterday afternoon 12.0V
Engine on 14.9V
No voltage drop connected or disconnected stayed a steady 12.0V after 10 minutes.
Truck performed flawlessly the day prior to the extremely cold temperatures. No lights left on or anything other than routine operation and shutdown. The only variable was the low temp.
You would have to leave the cable connected overnight to get an apples to apples comparison.
You also need a before and after voltage, and of course, one where any surface charge (does an AGM even get that) is worn off. IE shut down the truck, turn the lights on for say 30 seconds, then off, if they don't stay on for a while and then measure the voltage. If they stay on for a while, just wait until they turn off and take your initial voltage reading. Better yet, wait until the battery gets to ambient temp and then check the initial voltage.

Leave it overnight and measure again in the AM.

Do the same full procedure overnight with the battery disconnected. I.E. disconnect it just before the initial voltage test, leave it disconnected and then test again in the AM.

This will take a couple of nights. One just leaving it connected. A second overnight with the disconnected battery.

Compare and contrast the results.
I wouldn't expect a disconnected battery to drop more than 0.1v after a week (assuming similar BATTERY temps when voltages are checked), so certainly not that much overnight if there is no load on the battery.

Of course, I don't know what temps do the voltage. I know the capacity drops as the battery gets colder.

If both overnights are roughly the same it should be a reasonably valid comparison to see if the behavior changes connected vs disconnected.
If you get the same results connected vs disconnected, there is something wrong with the battery. If you don't, then the problem is likely in the vehicle.
 
You would have to leave the cable connected overnight to get an apples to apples comparison.
You also need a before and after voltage, and of course, one where any surface charge (does an AGM even get that) is worn off. IE shut down the truck, turn the lights on for say 30 seconds, then off, if they don't stay on for a while and then measure the voltage. If they stay on for a while, just wait until they turn off and take your initial voltage reading. Better yet, wait until the battery gets to ambient temp and then check the initial voltage.

Leave it overnight and measure again in the AM.

Do the same full procedure overnight with the battery disconnected. I.E. disconnect it just before the initial voltage test, leave it disconnected and then test again in the AM.

This will take a couple of nights. One just leaving it connected. A second overnight with the disconnected battery.

Compare and contrast the results.
I wouldn't expect a disconnected battery to drop more than 0.1v after a week (assuming similar BATTERY temps when voltages are checked), so certainly not that much overnight if there is no load on the battery.

Of course, I don't know what temps do the voltage. I know the capacity drops as the battery gets colder.

If both overnights are roughly the same it should be a reasonably valid comparison to see if the behavior changes connected vs disconnected.
If you get the same results connected vs disconnected, there is something wrong with the battery. If you don't, then the problem is likely in the vehicle.
Don’t have the time or inclination for all that, but did charge it to 100% yesterday then disconnected the negative cable and let it sit for 24 hours. Almost exact temperature today as yesterday.
Start of test: 100% charge, 12.4V
Almost 24 hours later: 48% charge, 12.0V.
Going to see about a test and replacement tomorrow.
 
Don’t have the time or inclination for all that, but did charge it to 100% yesterday then disconnected the negative cable and let it sit for 24 hours. Almost exact temperature today as yesterday.
Start of test: 100% charge, 12.4V
Almost 24 hours later: 48% charge, 12.0V.
Going to see about a test and replacement tomorrow.
Your battery is shot. A fully charged battery should settle to around 12.7 volts.
 
Don’t have the time or inclination for all that, but did charge it to 100% yesterday then disconnected the negative cable and let it sit for 24 hours. Almost exact temperature today as yesterday.
Start of test: 100% charge, 12.4V
Almost 24 hours later: 48% charge, 12.0V.
Going to see about a test and replacement tomorrow.
So, did you get a replacement?
 
So, did you get a replacement?
At a loss again. They tested it and said it passed, so back in the truck it went but did some more testing this time.
Read the battery again before installing, read 12.7V and 650CCA at 55 degrees F (rated 840 @ 0F). Hooked it up and checked for a parasitic draw, measured 10mA which is nice and low.
Alternator is still kicking out 14.9V.
So to make sure my measurement tools were not giving me bad info, took it to autozone to have them check everything on their tester. Battery and charging system passed, but she said the battery read 61% capacity, which is odd because I had driven it for 15 minutes and it was at 100% before I installed it.
Started taking pictures of my test readings in case this turns into a warranty battle.
 
How reliable are the testers being used? some of the new electronic testers get pretty wild readings sometimes. Can you measure the voltage at the battery while your starter cranks? You’ve got 4 or 5 years of warranty
 
learned something THANKS! never heard of an EFB battery but flooded batteries can last it kept filled +charged in very hot dry areas being able to keep it easily topped up is great. aunts 99 jeep went 7 years on a flooded interstate even driving only a little + the small high output flooded interstate in my 2011 fronty is about 6 YO although i keep it topped up with my CTek charger as i drive only a little being retired
 
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