RTH please: electrical charging and battery system isssue

[e9999]

In a bit of a bind here, leaving town in a couple of days and scrambling to do so, and now the 100 is developing (possibly) an issue. So I got to figure this out with no time and fast if possible. And no time to search so I beg your forgiveness on that last one.
And what better place to ask than our great MUD experts, right?

- so here: it seems like the battery on the 100 is going dead in just a week or 2 (not sure) when the truck is not driven.
- Battery is Sears Gold, 2 years old. Asked for a new one under warranty, but...
- Sears claims the battery is good and the alternator is acting up. News to me!
- They tested it for holding charge. Took about 3/4 hr or so. Wasn't there and not sure how they can do that. But they claim it's good.

As it stands now, the battery was about 12.6 V with engine off an hour after engine was turned off. Maybe 75F ambience. Seems fine. But it may have been supercharged at Sears and the truck was driven a bit (10 miles).

Here comes the question:
When I started the engine and idled it after the "inspection", the battery voltage goes to 13.8V. That does seem a little lower than usual, but then again maybe the battery is fully charged now. I just don't know.
When revving to 2000 rpm it goes only up to 13.9V, not over 14V. Also seems low. Then again, this seems low compared to my 80, not from detailed knowledge of the 100 voltages.
So either the alternator is indeed acting up (low voltage?) or that battery is so full that the alternator is not pushing the voltage to 14V plus. Or it's normal for a 100 and the battery is just plain bad.
Actual questions: What do you measure at the battery posts when the battery is fully-charged but after a start and with the engine idling? Is it also about 13.8V or much more?
What voltage do you see when you kick up the rpm on yours?
Thoughts on what could be wrong, if anything besides the battery, here?
thanks much

 

[rival1]

A fully charged battery should read between 12.8-13.2 the alternator should be putting out around 14v.

 

[agaisin]

I recently went through a battery/starting/charging saga and I believe I'm out of the woods.

My threads were here: https://forum.ih8mud.com/100-series...hs-30a-bat-fuse-has-500ma-draw-what-next.html
and here:
https://forum.ih8mud.com/100-series-cruisers/561796-generator-alternator-issues.html

I'll address your questions inline below:

- so here: it seems like the battery on the 100 is going dead in just a week or 2 (not sure) when the truck is not driven.

What symptoms are you getting that make you think it's going dead? How certain are you that battery was dead vs. a starter or starter contact issue?

- Sears claims the battery is good and the alternator is acting up. News to me!

How do they know alternator is acting up?

Here comes the question:
When I started the engine and idled it after the "inspection", the battery voltage goes to 13.8V. That does seem a little lower than usual, but then again maybe the battery is fully charged now. I just don't know.
When revving to 2000 rpm it goes only up to 13.9V, not over 14V. Also seems low. Then again, this seems low compared to my 80, not from detailed knowledge of the 100 voltages.
So either the alternator is indeed acting up (low voltage?) or that battery is so full that the alternator is not pushing the voltage to 14V plus. Or it's normal for a 100 and the battery is just plain bad.
Actual questions: What do you measure at the battery posts when the battery is fully-charged but after a start and with the engine idling? Is it also about 13.8V or much more?
What voltage do you see when you kick up the rpm on yours?
Thoughts on what could be wrong, if anything besides the battery, here?
thanks much

Spec for Alternator is 13.2-14.8 with the engine at 2k.
After my saga where I ended up cleaning up the battery terminals and clamps I now get about 14V until the car warms up (battery gets juiced) and then I'm down to about 13.4 at lowest when idling and up to about 13.8 at speed/2k rpm.

My advice to you is to get your charging/starting system tested at your local auto shop. They'll run a battery test, a starter test and an alternator test.

In my case, for what it's worth, after multiple dead batteries and having the charging/starting system test good, what appears to have resolved my issue was cleaning the terminals and clamps and connections (and using dielectric grease to prevent future issues). I had been under the (false) impression that if I had a good enough connection for juice to get from the battery to the starter then I was good, but I had a helpful poster on my thread that pointed out otherwise - when starting the current is higher and I might get enough juice through to start but not enough to charge the battery once the current goes down.

Anyhow - quickest/easiest thing to do is get the system tested at local shop. Regardless of what they tell you it probably is smart to clean up your terminals and clamps and connections and use dielectric grease to keep it in good shape. If they tell you everything checks out perhaps you had the same problem as me. If they identify a problem with your system then you'll have somewhere else to look.

I'll just warn you that in my case I mistakenly thought my alarm system was causing a parasitic draw but I believe that was a case of high initial draw vs. sleep mode draw.

Also, in my case, my saga started with my original battery 'dead' on ~2/11/2012, then a new battery (Diehard Platinum) that died 2 more times b/w then and 4/1/2012, and now no issues since 4/5/2012 when I cleaned everything up and saw the immediate voltage increase across the board. So given that I'm still driving it on the same ~weekly schedule and my numbers went up I feel confident that was really the issue.

 

[Trunk Monkey]

Ive never seen over abt 13.5v on SG or obd. Have the alt. tested.

Sent using my non-opposable thumbs

 

[e9999]

A fully charged battery should read between 12.8-13.2 the alternator should be putting out around 14v.

I don't think that a normal lead acid battery would go over 12.8 fully charged and rested. I believe 12.7V at about 70F is already 100% charged.

 

[e9999]

I recently went through a battery/starting/charging saga and I believe I'm out of the woods.

My threads were here: https://forum.ih8mud.com/100-series...hs-30a-bat-fuse-has-500ma-draw-what-next.html
and here:
https://forum.ih8mud.com/100-series-cruisers/561796-generator-alternator-issues.html

I'll address your questions inline below:


What symptoms are you getting that make you think it's going dead? How certain are you that battery was dead vs. a starter or starter contact issue?


How do they know alternator is acting up?



Spec for Alternator is 13.2-14.8 with the engine at 2k.
After my saga where I ended up cleaning up the battery terminals and clamps I now get about 14V until the car warms up (battery gets juiced) and then I'm down to about 13.4 at lowest when idling and up to about 13.8 at speed/2k rpm.

My advice to you is to get your charging/starting system tested at your local auto shop. They'll run a battery test, a starter test and an alternator test.

In my case, for what it's worth, after multiple dead batteries and having the charging/starting system test good, what appears to have resolved my issue was cleaning the terminals and clamps and connections (and using dielectric grease to prevent future issues). I had been under the (false) impression that if I had a good enough connection for juice to get from the battery to the starter then I was good, but I had a helpful poster on my thread that pointed out otherwise - when starting the current is higher and I might get enough juice through to start but not enough to charge the battery once the current goes down.

Anyhow - quickest/easiest thing to do is get the system tested at local shop. Regardless of what they tell you it probably is smart to clean up your terminals and clamps and connections and use dielectric grease to keep it in good shape. If they tell you everything checks out perhaps you had the same problem as me. If they identify a problem with your system then you'll have somewhere else to look.

I'll just warn you that in my case I mistakenly thought my alarm system was causing a parasitic draw but I believe that was a case of high initial draw vs. sleep mode draw.

Also, in my case, my saga started with my original battery 'dead' on ~2/11/2012, then a new battery (Diehard Platinum) that died 2 more times b/w then and 4/1/2012, and now no issues since 4/5/2012 when I cleaned everything up and saw the immediate voltage increase across the board. So given that I'm still driving it on the same ~weekly schedule and my numbers went up I feel confident that was really the issue.

first time after a coupla weeks there was no power at all left. Fully dead, not a peep. Recharged it and cranked fine.

This time some power left but not enough to crank. Recharged and it cranked fine.

I think their diagnosis of the alternator is based on guesses and wishful thinking and maybe low voltage (if I'm even right on that one).

so your voltage is not any higher than mine it seems

thanks

 

[e9999]

Ive never seen over abt 13.5v on SG or obd. Have the alt. tested.

Sent using my non-opposable thumbs

no kidding? I'm surprised that it's so low. On my 80 it's well into the 14V until it drops to about 13.9 when fully charged.

 

[e9999]

so if one should not expect 14V+ then the alt may be OK after all... I doubt that 13.9 is excessive.

 

[agaisin]

Regarding Alternator output, again the FSM says 13.2-14.8, pretty wide range. >13.5 is not a problem at all. If anything I'd be more concerned with never getting more than 13.5V.

I should point out - my LX is stock. If you have any electrical mods I guess 'normal' Voltage could be different than what I see or than what's in the fsm. Also, if you have any electrical mods it could be a source of draw.

You should probably also check for parasitic draw just to eliminate it - if you're getting a constant draw > 50mA with everything off you have reason for concern. And if you isolate your constant >50mA draw to something other than the anti-theft system then that would be a likely candidate...

 

[e9999]

yes, an odd draw could possibly do it, but no time to check that.

I just checked the 80 for comparison. My battery there is I think fully charged, desulfated, with truck used a lot recently. It reads 12.70V at about 70F, right where it should be. (The 100 battery was 12.60V though, but that one may not be fully charged.)
So I fired it up, and even with what I think is a fully-charged battery, the voltage shot up to 14.6V at idle. Not surprising, and as I mentioned it always fairly quickly get back down to 13.9 or so after the cranking depletion is refilled. And sure enough, the voltage stayed there rock steady even when going up to 3000 rpm.

So basically same behavior as the 100, just a different voltage level at idle. And I would of course expect the alternator circuits to be better on the newer vehicle so maybe the voltage regulators are set up differently.

So, I'm thinking the 100 alternator is just fine and the Sears guy was full of it. Probably the battery.

Anybody else on 100 voltages at idle?

 

[SR.GRINGO]

Figured I would provide some data points.

1st pic is an 06 produced in 8/2005 with original Panasonic battery... It was last driven on Saturday.




Sent from my phon

 

[e9999]

Figured I would provide some data points.

1st pic is an 06 produced in 8/2005 with original Panasonic battery... It was last driven on Saturday.


View attachment 630837

Sent from my phon

thanks for taking the time.
I take it that's with the engine off.
(Seems a bit low unless it's pretty cold out your way but that's a good long time. Our OEM panasonic lasted 7 years I think, darn good.)

 

[SR.GRINGO]

Cruiser #2 was produced in 3/2006 and still has the original Panasonic. It was driven two hours ago.





Sent from my phon

 

[SR.GRINGO]

Both have the engine off. It is 85 degrees right now. I suspect Cruiser #1 is close to getting a new battery.

Sent from my phon

 

[e9999]

Cruiser #2 was produced in 3/2006 and still has the original Panasonic. It was driven two hours ago.



View attachment 630847

Sent from my phon

that's more like it. Although it does take a while for the voltage to go down to "steady" level after running.
do you know what it gives with engine at idle?

 

[SR.GRINGO]

This is Cruiser #2 a/c off....at idle. Parking lights on....noted a high of 13.67



Sent from my phon