What does your 12V dash meter read?

[Slate]

Just curious what normal should be when on the HV battery power, versus when you are on ICE.

I understand that "normal" should be 14 or so, but that also implies the smart alternator is on. I have also read where normal volts for a 12V is 12.7-12.9. I was driving around today and it read 12.5V - 12.7V.

Trying to figure out some battery issues - Yes, I have a replacement in the mail. My 4XE is a '23 Rubi with just over 5K miles. I have ARB, winch, and lightbar.

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[Slate]

Wanting to make sure I don't have a problem with the dc/dc converter or the "smart alternator". Seems like the HV should have "turned on" and bumped the voltage up to top off the 12V battery?

 

[Mgg253]

Just got back from almost 3k mile trip, I got a little consumed worrying my battery was going to crap out. 14.2-14.4 was full charge start in the morning. On long days running air and driving 100’s of miles it steadily decreased. Every 20ish min it would got down .1. After 250 miles it might be showing 13.2 ish.

battery is 2 years old and 14-17k miles for this trip. After sitting overnight I was charged back up, but this behavior continued the entire trip. I just didn’t want to be stuckon a trail with 13.2V showing not being able to start or something. I maintained a charge in my HV battery the entire trip for this reason (thinking at least it tenders the battery overnight)

 

[Slate]

Thanks Michael for your reply and information. We just got back from town and on the way there and back I was on HV battery for the vast majority of the time and my dash meter read 12.5-12.6.

The trip is about 15 mins each way and about 9 miles. So well within the range of the HV battery - which is nice!

However, the volt meter never showed a spike that would imply that the HV is "charging" the 12V. The ICE did kick on a few times when my foot got heavy and in both cases, the voltage never changed.

My concern is that the HV battery is in fact, NOT coming on to top off the 12V battery (10 months old). I hadn't driven it in a few days and actually put a trickle charger on it for a couple of days. (This is absolutely ridiculous that I would even have to do that, but this is the crappy 12V world we live in.) By contrast, my 2012 F150 has sat for 3 straight weeks without being started and fires right up - all on the original old-by-now 12V battery.

I have an Odyssey in the garage, just waiting for some time to swap it out, and I really hope that solves the problem, but I am concerned it is more than just a crappy OEM 12V.

To round this out, when I picked it up from the dealer last weekend, the 12V battery was fully topped off and would show in the low 14's and then dip down to the mid 13's. That trip was about an hour long and was pretty much all on ICE (wish the dealer had topped off the HV, but oh well).

So I have seen it work, at least as much as I can, but it looks like if the Voltage is below 13.x is just won't send power to the 12V. I understand the smart alternator will come on and off, so it is normal to see the voltage bounce around a bit, but lately, it stays at 12.5 volts.

There are various charts online of course, but at 12.5 or 12.6 Volts, it looks like my battery SOC is just 80%-90% whether I am driving or not and whether I am on the ICE or the HV and regardless if/when I leave the HV plugged into the wall.

Just trying to make sure I don't have a bigger problem at hand...

 

[JP52]

I think you guys are looking at this the wrong way. A fully charged battery is about 12.7 or so. When you see the display is 13+ it means the battery is being charged. The higher the voltage the more the system is trying to charge the battery. As the battery reaches full charged the voltage the smart system applies goes down. That's why when you start driving it is 14 or so volts but then drops down as the battery charges. If you really want to know the condition of your battery check it with a multimeter after it has been sitting for a while or overnight. You can also check the voltage on the dash display before you start the jeep, but in my jeep it is lower than the meter. It reads about 12.2 while the meter will read 12.5 or higher. Maybe the in-vechicle meter is a ways from the battery so the voltage drops a bit. My jeep is a conventional ICE, but from what you describe your jeeps seem to be behaving the same way.

 

[Deleted User 38384]

Mine averages at 13.1

 

[Mgg253]

Anecdotally, when I first bought the 4xe, it would drop to 13.4-13.5 then the HV batt would shoot it up to 14.2-14.4 in a matter of seconds. That no longer happens.

there has also been software updates, but it was of concern when running trails where recovery is not easy!

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