Voltage reading 12.5 volts after changing main battery

[sharpsicle]

As for removing the IBS. I will once the truck is out of warranty.

Why would you remove the IBS entirely? @ShadowsPapa isn't saying to take it out and throw it away, he's saying to completely remove it to prompt it to reset. You still reinstall it after that. Don't toss it.

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[ShadowsPapa]

Why would you remove the IBS entirely? @ShadowsPapa isn't saying to take it out and throw it away, he's saying to completely remove it to prompt it to reset. You still reinstall it after that. Don't toss it.

Exactly. I'm saying take it off the battery terminal/post, and take it off the ground cable and even the LIN connection. Technically that should not matter as there's no "power" but the way I've seen weird things go, when I disconnect something to discharge or reset it, it gets disconnected. No little rogue electrons.

You want the IBS in there, otherwise, you risk worse troubles than you have.

I know FCA says they aren't bad unless there's a code, and they won't cover one under warranty unless there's a code saying it's bad, however........ that doesn't mean something can't go bad in such a way as to be too high in resistance across the shunt or some other subtle failure that causes false readings. So if a full reset, taking it loose from the small LIN connection, off the battery terminal and off the ground cables doesn't reset things, and the battery or batteries are otherwise ok, I'd wonder about an IBS issue. Rare, but happens.

By the book, disconnecting it from the battery alone is supposed to reset it but the other connections are like an additional 30-40 seconds, I go for full disconnect, set it aside for a while, then put it back when the battery/batteries are fully charged and known to be at full voltage.
Then put it all back together, including the IBS.
Issues going forward point to something else going on.

I recently had a freaky issue when testing a guy's alternator I had just restored - another guy wanted to buy a rare NOS (new old stock) regulator from me so I figured I'd test them both.
Connected things up and started to spin the alternator and watched the voltage as it shot clean over to the top of the DC scale (about 18 volts). FAST shutdown!
Man, that new regulator must have been bad. Rare - but it happens.
I grabbed another regulator I knew was fine from a prior alternator test and put it on.
Similar results but the voltage jumped up to 16, then down to 12, then 14, and up and down, hitting 16+ and sticking there a bit, then back down to 14 and I'm like what the #$@%
The battery I use is very old - the old lead acid type, likely 15 years old, not sealed. Last test I had laid the test leads on the bench a few inches from the battery.
I looked and saw a light layer of oxidation on some of the connectors and the alligator clips had started to rust where they clamped onto the battery posts.
Cleaned things up - better, but voltage still jumped around a lot, including spikes well over regulated voltage.
In the end a ground connection had enough voltage drop that the regulator was assuming low voltage and kicking the field current up in an effort to get up to normal. The drop across that ground connection was intermittent and once in a while the voltage dropped to perfect levels.
Further cleaning of ground connections and all was good - including the NOS regulator worth probably $250 to the right person.
All that reminded me of things I have known and preached for decades - connections can look good, but a bit of oxide to cause a slight voltage drop, especially where sensing voltage and load is involved and things get whacky.
I've seen alternators, regulators and batteries all replaced because of a single bad ground connection (of course the fakebook people who responded to the guy said "it's the regulator, replace it", then when that failed "then it has to be the alternator, replace it" and the guy tossing his arms up said ok, all that's left is the battery and he replaced that. I said - check the ground connection where the regulator connects to the main harness, and check the ground terminal where the regulator ground connects to the alternator.
10 minutes and 0 dollars later, it was fixed - after he spent money for all those new parts.

 

[ShadowsPapa]

Why would you remove the IBS entirely? @ShadowsPapa isn't saying to take it out and throw it away, he's saying to completely remove it to prompt it to reset. You still reinstall it after that. Don't toss it.

Thanks for watching and catching that - I guess I wasn't totally clear in putting it BACK when all was said and done. I hurry.

Was occupied with testing new throttle linkage between the dual quads on the Javvy today - glad I tested - had a rod a bit too long and was holding the rear carb open off idle.

 

[Towzone100]

Why would you remove the IBS entirely? @ShadowsPapa isn't saying to take it out and throw it away, he's saying to completely remove it to prompt it to reset. You still reinstall it after that. Don't toss it.

Sorry, I misread it. That is exactly what I did to start the relean process. Uninstall it completely let it sit on my bench for two hours.

This is the second time I replaced a battery. The first time was much smoother but then again I replaced it with another H6.

Thanks for the catch.

 

[Towzone100]

Exactly. I'm saying take it off the battery terminal/post, and take it off the ground cable and even the LIN connection. Technically that should not matter as there's no "power" but the way I've seen weird things go, when I disconnect something to discharge or reset it, it gets disconnected. No little rogue electrons.

You want the IBS in there, otherwise, you risk worse troubles than you have.

I know FCA says they aren't bad unless there's a code, and they won't cover one under warranty unless there's a code saying it's bad, however........ that doesn't mean something can't go bad in such a way as to be too high in resistance across the shunt or some other subtle failure that causes false readings. So if a full reset, taking it loose from the small LIN connection, off the battery terminal and off the ground cables doesn't reset things, and the battery or batteries are otherwise ok, I'd wonder about an IBS issue. Rare, but happens.

By the book, disconnecting it from the battery alone is supposed to reset it but the other connections are like an additional 30-40 seconds, I go for full disconnect, set it aside for a while, then put it back when the battery/batteries are fully charged and known to be at full voltage.
Then put it all back together, including the IBS.
Issues going forward point to something else going on.

I recently had a freaky issue when testing a guy's alternator I had just restored - another guy wanted to buy a rare NOS (new old stock) regulator from me so I figured I'd test them both.
Connected things up and started to spin the alternator and watched the voltage as it shot clean over to the top of the DC scale (about 18 volts). FAST shutdown!
Man, that new regulator must have been bad. Rare - but it happens.
I grabbed another regulator I knew was fine from a prior alternator test and put it on.
Similar results but the voltage jumped up to 16, then down to 12, then 14, and up and down, hitting 16+ and sticking there a bit, then back down to 14 and I'm like what the #$@%
The battery I use is very old - the old lead acid type, likely 15 years old, not sealed. Last test I had laid the test leads on the bench a few inches from the battery.
I looked and saw a light layer of oxidation on some of the connectors and the alligator clips had started to rust where they clamped onto the battery posts.
Cleaned things up - better, but voltage still jumped around a lot, including spikes well over regulated voltage.
In the end a ground connection had enough voltage drop that the regulator was assuming low voltage and kicking the field current up in an effort to get up to normal. The drop across that ground connection was intermittent and once in a while the voltage dropped to perfect levels.
Further cleaning of ground connections and all was good - including the NOS regulator worth probably $250 to the right person.
All that reminded me of things I have known and preached for decades - connections can look good, but a bit of oxide to cause a slight voltage drop, especially where sensing voltage and load is involved and things get whacky.
I've seen alternators, regulators and batteries all replaced because of a single bad ground connection (of course the fakebook people who responded to the guy said "it's the regulator, replace it", then when that failed "then it has to be the alternator, replace it" and the guy tossing his arms up said ok, all that's left is the battery and he replaced that. I said - check the ground connection where the regulator connects to the main harness, and check the ground terminal where the regulator ground connects to the alternator.
10 minutes and 0 dollars later, it was fixed - after he spent money for all those new parts.

Hey, ShadowsPapa. Thanks for all the insight. It looks like the learning process is just about complete. I say that because the volt gauge is not jumping all over the place. I'll check the resistance of the IBS sensor once the "recommended relearn time" has passed, and I will still read the old bad data.

I hear what you are saying about connection. I have said the same thing all my life. Check your connections first. I will have to say. Even though I wish I could throw a programmer on my truck like a BMW and program the new battery information, at least the IBS learning process has not stained the battery during the process. I purchased it brand new at 12.8 volts, which is still at 12.8 volts.

Thanks again for the insight. Much appreciated.

 

[Towzone100]

Quick update. Its been 5 starts with more than 8 hours between and my voltage is still floating around from 12.6 to 13.9. It tends to sit around 13.1. I wonder if this is part of the smart charging process.

 

[Hootbro]

I wonder if this is part of the smart charging process.

It is. Perfectly normal.

 

[Towzone100]

It is. Perfectly normal.

Thanks for the insight. I figured as much. It's the first time it's acted this way but then again I deleted the AUX battery and upgrade to an Optimal H7. It's a beast of a battery.

With factory battery and the AUX connected it always charging.

 

[Hootbro]

Thanks for the insight. I figured as much. It's the first time it's acted this way but then again I deleted the AUX battery and upgrade to an Optimal H7. It's a beast of a battery.

With factory battery and the AUX connected it always charging.

I have done the aux battery delete twice and it took awhile (maybe a couple weeks) each time for charging to level out and not have the wild swings.

I never bothered resetting the IBS logic so that probably may have played into it.

 

[ShadowsPapa]

Quick update. Its been 5 starts with more than 8 hours between and my voltage is still floating around from 12.6 to 13.9. It tends to sit around 13.1. I wonder if this is part of the smart charging process.

Couple of possible reasons for the very different voltages from a totally stock system -
You've got one battery,
That battery is likely a far better battery, lower internal resistance,
perhaps doesn't get as warm when charging as the stock batteries,
also likely holds the charge much better, meaning less swings.

As long as the battery stays charged, and you can do a spot "feel good" check every few days to see how the voltage is using a meter at the battery posts.
If it's up there 12.6 or better - who can argue with that?

 

[Towzone100]

Couple of possible reasons for the very different voltages from a totally stock system -
You've got one battery,
That battery is likely a far better battery, lower internal resistance,
perhaps doesn't get as warm when charging as the stock batteries,
also likely holds the charge much better, meaning less swings.

As long as the battery stays charged, and you can do a spot "feel good" check every few days to see how the voltage is using a meter at the battery posts.
If it's up there 12.6 or better - who can argue with that?

All makes sense. This battery is far superior to the stock.

 

[ShadowsPapa]

All makes sense. This battery is far superior to the stock.

I could jokingly suggest that even a Walmart battery would be - but would it be a joke, or truth?

 

[Towzone100]

I could jokingly suggest that even a Walmart battery would be - but would it be a joke, or truth?

It's that the truth.

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