Alternator Charge Voltage

[Willwork4truck]

Dunno about E T however a FLA battery (non-AGM) is 12.7, I think AGM is 12.8X At 100% state of charge. Kinda’ surprised that the ET 12v battery is so much higher Resting voltage. I know its a 48v to (nominal) 12v system, however what “12v” battery sits at 14.6 volts? New to me, but then a lot of things are “new” to me... (pointless ignitions, non-carburated fuel systems, alternators instead of generators, uhh, radial instead of bias-ply tires... just a few things have changed since my 1956 Buick Century...

 

[Fastman21]

Dunno about E T however a FLA battery (non-AGM) is 12.7, I think AGM is 12.8X At 100% state of charge. Kinda’ surprised that the ET 12v battery is so much higher Resting voltage. I know its a 48v to (nominal) 12v system, however what “12v” battery sits at 14.6 volts? New to me, but then a lot of things are “new” to me... (pointless ignitions, non-carburated fuel systems, alternators instead of generators, uhh, radial instead of bias-ply tires... just a few things have changed since my 1956 Buick Century...

My bad I miss spoke that voltage is with the truck idleing.

 

[Jtr]

Still meaning to get to my resting pre and post trickle charge. I would be curious if anyone else with etorque can replicate my "low" resting state between 12.3 and 12.4 that I got most recently.

 

[Willwork4truck]

Still meaning to get to my resting pre and post trickle charge. I would be curious if anyone else with etorque can replicate my "low" resting state between 12.3 and 12.4 that I got most recently.

A guy just posted that his generator went out and he had gotten the service engine and battery light/messages. The generator wasn’t charging his battery. Maybe you’d better run it by the dealer just in case...

 

[Jtr]

12.16 prior to charging. That was right after opening the vehicle door to unlatch the hood and I had my adjustable side steps operate. Which is a pretty poor considering the truck sat all night even with the power needed to operate the steps. Trickle charge got me up to 12.87. I'll definitely have to keep an eye on it and as @Willwork4truck mentioned, I'll have to do periodic charges especially during the cold winter months ahead.
If I run into further 12v battery charge issues I'll post on this thread.

 

[kittyjo]

Something is draining ur battery that low or it’s bad . A battery can’t drain itself.if u have a way to check the cca s it has to be above 700 if not then it’s bad. A local interstate battery place can check that for u.

 

[Willwork4truck]

Something is draining ur battery that low or it’s bad . A battery can’t drain itself.if u have a way to check the cca s it has to be above 700 if not then it’s bad. A local interstate battery place can check that for u.

I replaced the battery in my 14 Edge (original) with a WM largest I could fit this July. It load tested bad (200 under rated CCA’s) a couple weeks ago at an oil change place (Firestone). Course they wanted to sell me a $147 battery (WM was $109 same size 5 yr warranty) so I took it back to WM. Sure enough it load tested bad and they replaced it no questions asked. So yes, new batteries sometimes go bad.
Someone commented a while back on a different thread that the auto parts stores computerized load testers are just to sell new batteries... well conspiracy theories aside, it’s what’s used by most places now so I will accept it. Besides, my battery was going on 6 yrs old from the in-service date and it was cranking slower, and winter’s about here...

 

[kittyjo]

I replaced the battery in my 14 Edge (original) with a WM largest I could fit this July. It load tested bad (200 under rated CCA’s) a couple weeks ago at an oil change place (Firestone). Course they wanted to sell me a $147 battery (WM was $109 same size 5 yr warranty) so I took it back to WM. Sure enough it load tested bad and they replaced it no questions asked. So yes, new batteries sometimes go bad.
Someone commented a while back on a different thread that the auto parts stores computerized load testers are just to sell new batteries... well conspiracy theories aside, it’s what’s used by most places now so I will accept it. Besides, my battery was going on 6 yrs old from the in-service date and it was cranking slower, and winter’s about here...

6yrs is pretty good life for a battery life. I work for interstate batteries in nc and never pressure someone into buying it’s always the customers decision to if they want to or not. Autozone and Napa improperly charge the batteries at 50amps which frys the inside and love to tell u ur battery is bad 99% of the time hahaha but hey u pay for what u get!!!!

 

[Willwork4truck]

6yrs is pretty good life for a battery life. I work for interstate batteries in nc and never pressure someone into buying it’s always the customers decision to if they want to or not. Autozone and Napa improperly charge the batteries at 50amps which frys the inside and love to tell u ur battery is bad 99% of the time hahaha but hey u pay for what u get!!!!

I actually had Autozone check it with their loadtester (thats all they did) and it gave me a slightly lower CCA than Firestone. The guy never asked if I wanted a battery price, probably since I told him it was WM warrantied. So perhaps my store was honest, or an unmotivated employee. Either way it worked out.
Yes 6 years is good, but then I have been in the habit of charging it up once a month (12-18 hrs on 2 amps) regardless of how much I drive it, thanks to Ford’s notorious BMS (battery management system).

 

[Vincent r]

Still meaning to get to my resting pre and post trickle charge. I would be curious if anyone else with etorque can replicate my "low" resting state between 12.3 and 12.4 that I got most recently.

Im have same problem does your still do that

 

[Jtr]

I haven't notice it dip down to those levels since I charged the battery fully. I'll just need to stay on top of it and charge it monthly.

 

[Willwork4truck]

Im have same problem does your still do that

I went out yesterday and checked, after 2 full days of inactivity it read 12.22. Surprised me as it had been fully charged (according to the craptastic meter on the HF charger) earlier in the week. So I hooked the new 4 amp digital charger up and sure enough it started out at an indicated 12.2. Shouldn’t be that low, but then its not driven more than 1 or 2 days a week.

Brings back bad memories of the Ford battery management system woes that are still ongoing... its not uncommon for F150’s to need multiple batteries either annually or even sooner. They've not been able to trace the parasitic draw problems to any single issue however one caution that keeps coming up is all the aftermarket electronics; radar detectors, dash cams, extra lighting, switching bulbs to a non-oem led, brake controllers, stereos and amps... the list of possibilities goes on and on. Here’s a sample thread which may have to do with an older truck but if you go to the last (12) page, it applies to newer models as well:
Another 2013 F150 with dead battery overnight issues.
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1 2 3 ... Last Page)
Douda13 on 05-23-2014
09-24-2019 05:35 PM
by jmusmc1998
118 replies
108,354 views
General F150 Discussion

 

[kittyjo]

Battery is discharged a little bit and it’s getting a little bit drained cus of all the technology in the truck. On that charger it shud only take about 2 hrs to be fully charged at 4amps if it’s at 2 amps not much longer

 

[Willwork4truck]

KJ, it actually took about 4-5 hours last night before it reported 100%, I left it on all night anyway (it goes down to a 1 amp trickle) just cause. It’s a bit disconcerting that a stock Ltd with key fobs far away drops that low in a week however its still a warrantied battery and I’m around to check the SOC with a voltmeter. After charging today it shows 12.9 (thats with the surface charge) so I’ll see how long it takes to bleed off.
(Edit, 4 hrs later it reads 12.77)
I have not paged through the dash display screens to get the voltage, so I’d better do that for when we drive it.
Always something to check it seems. First world problem...

 

[Willwork4truck]

2.5 hours of highway driving yesterday, averaging 70, light traffic, no hills. (19.9 mpg). Had charged the battery 3 days earlier. Voltage this am was 12.54.
Kinda’ surprised that the resting voltage wasn’t at least 12.6+ after that much continuous driving. My suspicion is the computer not allowing the alternator to keep the battery charged up to save .01 mpg, as some of these “smart” systems are prone to do.
So keep a maintainer/charger around, you might need it vs a battery replacement. Note, E Torque won’t have this problem.

 

[jaksecret]

I went out yesterday and checked, after 2 full days of inactivity it read 12.22. Surprised me as it had been fully charged (according to the craptastic meter on the HF charger) earlier in the week. So I hooked the new 4 amp digital charger up and sure enough it started out at an indicated 12.2. Shouldn’t be that low, but then its not driven more than 1 or 2 days a week.

Brings back bad memories of the Ford battery management system woes that are still ongoing... its not uncommon for F150’s to need multiple batteries either annually or even sooner. They've not been able to trace the parasitic draw problems to any single issue however one caution that keeps coming up is all the aftermarket electronics; radar detectors, dash cams, extra lighting, switching bulbs to a non-oem led, brake controllers, stereos and amps... the list of possibilities goes on and on. Here’s a sample thread which may have to do with an older truck but if you go to the last (12) page, it applies to newer models as well:
Another 2013 F150 with dead battery overnight issues.
(

1 2 3 ... Last Page)
Douda13 on 05-23-2014
09-24-2019 05:35 PM
by jmusmc1998
118 replies
108,354 views
General F150 Discussion

I have a 2020 Ram 1500 with the regular 5.7 and its clear there is a problem with amp draw at rest. It was fine when i bought it, did not notice extreme charging, but i'm now at 1500 miles and the battery drops about .2V resting voltage per day, and no matter how far i drive it(50 miles total the other night) it charges at 14.6 the entire time. I've measured the amp draw at between 2.7 and 4.2 amps constant, which is obviously why the battery is draining. Local dodge dealer says there's not a problem until i can't start the truck. Yeah, right. so I'm keeping it charged with a smart charger so I can at least keep the battery healthy(which it is if i disconnect it-- reads 13V for days.) eventually i'll just drop it off at the dealer and make them fix it.

 

[kapinallinen2]

I am starting to get a feeling that the OEM batteries we have are a "bare basement" units. My truck will no longer drop down to entry/exit without running.

 

[Willwork4truck]

I am starting to get a feeling that the OEM batteries we have are a "bare basement" units. My truck will no longer drop down to entry/exit without running.

Hmm, likely right about lower end batteries. A switch to a quality AGM would be in order however the charging profiles for agm’s are different than lead acid (which is what we have I believe). The computer is likely not going to detect an agm battery and adjust its charging voltage, so in effect you could be chronically undercharging the battery thus shortening its life.

While this article/thread (38 pages!) is from a 2019 TacomaWorld forum (as opposed to FCA/RAM), it does explain the problems associated with switching out battery chemistries:

The NorthStar AGM Battery + Voltage Booster Upgrade​

Discussion in 'Technical Chat' started by crashnburn80, Apr 14, 2019.
TacomaWorld.com forum

If you are so interested, it is a good read and does a good job of explaining why and how an agm is a better kind of battery with certain limitations.

As for me, I just charge the truck about weekly with a 4 amp 3 stage battery charger. Harbor Fright $36 on sale but any brand of smart charger that’s got an adjustable battery type setting will do.

 

[Willwork4truck]

Checked the truck battery today, 3 days after its last 100 mile highway trip. It was down to 12.3 volts, that’s not good. The charts I see online say that this is roughly 60-65% state of charge for a lead acid chemistry battery. That’s why I put it on the 4 amp multi-stage charger about every 10 days.
After 6 hours, it was back up to an indicated 12.9, volts which is an artificially high surface charge but at least it’s back up again.

 

[kittyjo]

Checked the truck battery today, 3 days after its last 100 mile highway trip. It was down to 12.3 volts, that’s not good. The charts I see online say that this is roughly 60-65% state of charge for a lead acid chemistry battery. That’s why I put it on the 4 amp multi-stage charger about every 10 days.
After 6 hours, it was back up to an indicated 12.9, volts which is an artificially high surface charge but at least it’s back up again.

Sounds like a bad battery to me... unless it’s alternator but sounds like a bad cell if it’s refusing to stay charge.