Alternator Charge Voltage

[dalejrthecat]

What's everyone seeing for voltage from the alternator? When I picked up the truck new I remember the battery voltage meter being on the high side of the half way mark. Now it never even gets to the half way mark. Now I'm seeing warmed up driving on a 70 degree day 13.5 - 13.6v. Cold start 13.9v. 19 Rebel 5.7 Non Etorque with about 700 miles.

 

[riccnick]

That's normal, the alternator and regulator should keep the battery voltage between 13.5 and 14v while the engine is running.

 

[2019REBEL]

Mine runs up to 14.6 volts.

 

[Caliber40]

Just picked up my eTourque 5.7L and when starting the battery seems a little sluggish so I checked the battery voltage with the engine off and the voltage reads 12.6. (about 10 minutes after shutting down) . My experience with boat systems( I watch this stuff pretty closely) suggests the battery should be up over 12.8......maybe as high as 13 or so.

Anybody with experience on this?

 

[Edwards]

Just picked up my eTourque 5.7L and when starting the battery seems a little sluggish so I checked the battery voltage with the engine off and the voltage reads 12.6. (about 10 minutes after shutting down) . My experience with boat systems( I watch this stuff pretty closely) suggests the battery should be up over 12.8......maybe as high as 13 or so.

Anybody with experience on this?

There was a batch of bad 12V batteries on the 1500's that we read about last year. You could just have a bad battery. The eTorque system is also supposed to "jump" your 12V battery if it needs it.
Just get your battery checked out.

 

[Caliber40]

There was a batch of bad 12V batteries on the 1500's that we read about last year. You could just have a bad battery. The eTorque system is also supposed to "jump" your 12V battery if it needs it.
Just get your battery checked out.

Just charged it at 12A for about 3 hours and it sounds better starting up but the "engine off" voltage still reads 12.6 (which may be normal) so I guess it's back to the dealer next week for a battery check up. If I took my boat off charge and it read 12.6 I'd be concerned but I've never bothered to check this stuff on my cars before.

 

[Jtr]

I was having battery issues with my wife's vehicle and while I had my multimeter out I checked the Ram's battery. Engine off state was 12.35 volts. That seems low for only 8k miles on the truck. Does anyone have any thoughts on this or experience the same levels? I have the e-tourque.

 

[Richard320]

What's everyone seeing for voltage from the alternator? When I picked up the truck new I remember the battery voltage meter being on the high side of the half way mark. Now it never even gets to the half way mark. Now I'm seeing warmed up driving on a 70 degree day 13.5 - 13.6v. Cold start 13.9v. 19 Rebel 5.7 Non Etorque with about 700 miles.

Anywhere from 12.8 to 14.1. It depends a lot on temperature -- higher when cold -- and load. If the AC is on, it shows lower than AC off.

 

[Richard320]

I was having battery issues with my wife's vehicle and while I had my multimeter out I checked the Ram's battery. Engine off state was 12.35 volts. That seems low for only 8k miles on the truck. Does anyone have any thoughts on this or experience the same levels? I have the e-tourque.

A lot of modules may still be powered up for a few minutes. Even something as innocuous as opening the door to release the hood could trigger a bunch of stuff. When I worked for Toyota, it was standard for us to get everything set up and then walk away for ten minutes or so -- and even keep the key fob far away-- before checking for parasitic draw. I suggest you do the same. Unlock, pop hood, go inside and leave the key somewhere, then come back in ten minutes and see what the resting voltage is.

 

[kittyjo]

Just charged it at 12A for about 3 hours and it sounds better starting up but the "engine off" voltage still reads 12.6 (which may be normal) so I guess it's back to the dealer next week for a battery check up. If I took my boat off charge and it read 12.6 I'd be concerned but I've never bothered to check this stuff on my cars before.

So surprise it didn’t blow up ur suppose to charge it at max of 4 amps if at 11.6v anything lower 2 volts to properly charge a battery...

 

[Jtr]

A lot of modules may still be powered up for a few minutes. Even something as innocuous as opening the door to release the hood could trigger a bunch of stuff. When I worked for Toyota, it was standard for us to get everything set up and then walk away for ten minutes or so -- and even keep the key fob far away-- before checking for parasitic draw. I suggest you do the same. Unlock, pop hood, go inside and leave the key somewhere, then come back in ten minutes and see what the resting voltage is.

All great points. I've read elsewhere of batteries coming from the factory in less then full charge state so that's what had me scratching my head and wondering if that may be me as well. When I'm on the road I'm running at 14.4 so that seems to be fine. I'll follow your directions on letting the truck sit for a bit and keep the fob away.

 

[Willwork4truck]

Ive charged up starter batteries on the last 4 vehicles I’ve owned about 1x monthly even when driven daily. The new smart alternator gas saving crap ideas are keeping the alternator from being engaged as long thus less charging. I end up using a 3 stage automatic 10/2 amp charger and leave it on at least 12 hrs, sometimes more if I can keep the vehicle still that long. It usually first shows about a 75% charge level and then slowly tapers down to 0 amps, but it takes overnight.
Sulfation of lead acid batteries is their greatest killer, and thats from setting at less than 100% state of charge for too long. Resting voltage depends on the type/chemistry so the old fashioned flooded lead acid is different than todays AGM’s. I’d say 12.7x to 12.8 is closer to a healthy battery resting voltage (one not having had any charge or discharge just prior).
Whatever vehicle you have, use the appropriate type charger (one with settings for LA, AGM or Gel).
There are some well reviewed chargers (see Amazon) that have 5-8 different steps or cycles, dunno how good they are. Just don’t use the really old constant current types. I have a craptastic Harbor Freight and it works fine.

 

[Willwork4truck]

I checked the battery today about an hour after my wife brought the truck back in, 12.53 which was surprisingly low. I put it on the charger as I’ve seen Several of the the battery charts for sealed lead acid as needing to be at either 12.6+ or 12.7 to be 100% charged.
Advance Auto Parts says this:
WHAT IS THE IDEAL CAR BATTERY VOLTAGE YOU CAN HAVE?
Measuring your car battery’s voltage can be a great way to determine how charged your battery might be. The ideal car battery voltage range will provide you with a relevant interval according to which you can measure precisely what the voltage says about the battery’s current charge. A perfect voltage with the engine running is between 13.7 and 14.7V. With the engine off, you should get a reading of 12.6 volts. If the battery isn’t fully charged, it will diminish to 12.4V at 75%, 12V when it’s only operating at 25%, and down to 11.9V when it’s completely discharged. This data and the way it relates to the design of your battery should provide you with some useful insight into the functioning capacity of your car battery.

here’s another: (slightly higher voltage)

State of Charge	Sealed or Flooded Lead Acid battery voltage	Gel battery voltage	AGM battery voltage
100%	12.70+	12.85+	12.80+
75%	12.40	12.65	12.60
50%	12.20	12.35	12.30

 

[kittyjo]

I checked the battery today about an hour after my wife brought the truck back in, 12.53 which was surprisingly low. I put it on the charger as I’ve seen Several of the the battery charts for sealed lead acid as needing to be at either 12.6+ or 12.7 to be 100% charged.
Advance Auto Parts says this:
WHAT IS THE IDEAL CAR BATTERY VOLTAGE YOU CAN HAVE?
Measuring your car battery’s voltage can be a great way to determine how charged your battery might be. The ideal car battery voltage range will provide you with a relevant interval according to which you can measure precisely what the voltage says about the battery’s current charge. A perfect voltage with the engine running is between 13.7 and 14.7V. With the engine off, you should get a reading of 12.6 volts. If the battery isn’t fully charged, it will diminish to 12.4V at 75%, 12V when it’s only operating at 25%, and down to 11.9V when it’s completely discharged. This data and the way it relates to the design of your battery should provide you with some useful insight into the functioning capacity of your car battery.

here’s another: (slightly higher voltage)

State of Charge	Sealed or Flooded Lead Acid battery voltage	Gel battery voltage	AGM battery voltage
100%	12.70+	12.85+	12.80+
75%	12.40	12.65	12.60
50%	12.20	12.35	12.30

That’s voltage is actually wrong technically 12.55 is enough for car to start the engine.. a discharge is when u leave the lights on or door open overnight and needs to be charge at 4 amps properly for couple hours if below 12.10 if higher jump start it and drive it for 45 minutes and it will be charged. But agm batteries hold their voltage longer..... best batteries for the 19 is an Mtx-94r/h7

 

[Richard320]

I checked the battery today about an hour after my wife brought the truck back in, 12.53 which was surprisingly low. I put it on the charger as I’ve seen Several of the the battery charts for sealed lead acid as needing to be at either 12.6+ or 12.7 to be 100% charged.

Questions for you

Did you leave the key fob out of range? Otherwise it may have sensed it and started powering up modules.

By the same token, did you leave it unattended for ten minutes or longer to let all the modules power down?

 

[Jtr]

Questions for you

Did you leave the key fob out of range? Otherwise it may have sensed it and started powering up modules.

By the same token, did you leave it unattended for ten minutes or longer to let all the modules power down?

This may part of my problem. Due to the location of the attached garage to the kitchen where I leave my key fob it may be too close in range. I don't know what else I can do, other than keeping the fob on the separate end of the house, but even then it is still probably in range to unlock it.

 

[Willwork4truck]

Questions for you

Did you leave the key fob out of range? Otherwise it may have sensed it and started powering up modules.

By the same token, did you leave it unattended for ten minutes or longer to let all the modules power down?

Yes there was no key nearby and 2 hrs from last drive. I checked voltage this am after being on the charger, with the surface charge still reading its at 12.87, I’ll check it later today when thats bled off.
Point is, no matter whose chart a person uses, one should periodically charge the battery or use a maintainer to maintain health. No idea how the E Torque units respond to varying voltages, as I don’t have that.

 

[Jtr]

Yes there was no key nearby and 2 hrs from last drive. I checked voltage this am after being on the charger, with the surface charge still reading its at 12.87, I’ll check it later today when thats bled off.
Point is, no matter whose chart a person uses, one should periodically charge the battery or use a maintainer to maintain health. No idea how the E Torque units respond to varying voltages, as I don’t have that.

I'm going to give mine a trickle charge today and post before and after resting state readings.

 

[Willwork4truck]

Afterwards (off for 2 hours and opened the door a couple times/cycled the power running boards and computers), resting voltage is 12.71.

 

[Fastman21]

Just picked up my eTourque 5.7L and when starting the battery seems a little sluggish so I checked the battery voltage with the engine off and the voltage reads 12.6. (about 10 minutes after shutting down) . My experience with boat systems( I watch this stuff pretty closely) suggests the battery should be up over 12.8......maybe as high as 13 or so.

Anybody with experience on this?

5.7 etourque 14.6