Battery monitor now shows charging at 14.93 volts.

[hpwjr]

My Bluetooth battery monitor has been fairly consistent usually showing low charging rates unless I put the fan up to five when it jumps up to 14.3 or so. But today it has consistently shown high 14s! Just regular auto on climate control. That seems very high, even alarmingly so. Any ideas?

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[Avalance150]

Fairly normal alternator output and running voltage for maintaining AGM batteries. Nothing to be concerned about.

 

[hpwjr]

Okay, I just went out to check it again, and before starting it was at 12.20v which is often the case if it’s been sitting. I started up and it immediately jumped up to 14.58 and stayed there. It’s never done this before. It always has stayed low, too low. I’m not startled at 14.5 but 14.9 was higher than I’m used to. That’s getting close to equalization levels for a FLA battery.

 

[hpwjr]

My second post was written before the above post from Avalanche 150. It crossed. Thanks.

 

[Vater]

My Bluetooth battery monitor has been fairly consistent usually showing low charging rates unless I put the fan up to five when it jumps up to 14.3 or so. But today it has consistently shown high 14s! Just regular auto on climate control. That seems very high, even alarmingly so. Any ideas?

I have a battery monitor as well, actually 2 on my Powerboost. 14.8 to 15v is absolutely normal charging voltage on batteries that are AGM. A resting voltage of 12.2 is a bit low likely caused by parasitic drain while the truck is off over time is not unusual, but a bit low and I am sure the bump to pretty much full charging voltage of ~ 15v is driven by this. This is very typical as I have an AGM battery charger that I will charge my car batteries every month or so in the winter just to keep them closer to a decent resting voltage. With that, I always see the charger ramping voltage to ~ 15 during the charge cycle, which for AGM is the protocol which is a little bit higher voltage than would be for a flooded battery design.

 

[hpwjr]

I’m reassured that the voltage is within spec, but I’m still puzzled as to why I’ve not seen that high a voltage before. My concern has always been that my battery was getting insufficient voltage. Usually it hovered in the 13s. I guess in my observations I just always missed higher voltages. Before I could only get them by upping fan speed.

 

[Snakebitten]

Did you receive an OTA update recently?

 

[hpwjr]

Yes. I’ve wondered if something has changed in charging profiles. I’m now in the 24 update numbers.

 

[Gros Ventre]

Keep in mind that charging rates/voltages are controlled by temperature. The temperature sensor is located in the Pax side mirror assembly. I've observed my system voltage remaining higher than I'd expect given hours on the road at power. At any rate There is a temperature dependency between voltage and temperature for lead acid batteries and an AGM battery remains a lead acid battery with a few quirks because of construction. For exmple they are more susceptible to over charging. Hence my concern when winter weather keeps voltages higher than I'd expect after hours on the road. We'll see, my battery is going into its fourth winter...

 

[Shane150]

When charging, I've seen mine go close to or above 15 more than a few times.

 

[hpwjr]

I was just going to report a new high—15.11 volts. So I see I’m not the only one. It’s cold for here. Lower forties.

 

[Shane150]

I was just going to report a new high—15.11 volts. So I see I’m not the only one. It’s cold for here. Lower forties.

I am at 24.8F at my location right now!

 

[PB2021]

The charging system typically will not fully charge the AGM battery leaving it in the 85-90% state of charge change. This is not ideal long term. Part of the charge protocol is for the charging system to charge higher every so often to restore the battery from any ill affects of the normal 85-90% charge range. If you are seeing higher than normal this is likely occurring and will return to normal in likely a few drive cycles

 

[Gros Ventre]

On my coldest days I've seen 15.2VDC. 15.0VDC fits for around 25ºF in my observation. What I see for long term stable system voltage is 12.8VDC. That's mid-summer and a long enough drive for temps to settle out. Once fall got here and temps were around 20-40ºF I'm seeing 14.7-15.0 VDC.

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