12v battery voltage?

Yeah that is very low. Are you low usage, the car regularly sits idle for a day or two? Or, considering it's 2018: what month did you buy, and what was the build month (the latter's on the decal in the driver's door frame). It mighta sat on dealership lot for a while? There's a constant low-level drain on the battery when it's hooked up, and protracted idle time will run it down.

How recently did you buy: they may give you a goodwill new battery? Or warranty?

If no such luck at dealership, I would get it on a smart charger, something that will assess the battery and run a charging regimen. Not sure what the amp limit is on 4th gen, but you should be safe with 4 amp max, regardless.

You might get it tested with a digital load tester too, to really see where you stand.

 

the only caveat: did you open the drivers door to pop the hood?

 

I wouldn't be concerned. I'd repeat the test at some other time anyway - also with a different voltmeter.

John Kelly at Weber University comments that above 12.0 volts is fine (from 9:00 to 9:50). Prior to that he talks about readying the battery to get a voltage reading.

 

so there is some drain when you do that. try popping the hood, then testing it later, or even in the morning.

 

Nothing to worry about. The voltage will vary. As was mentioned, opening the driver's side door to unlatch the hood fired up the brake accumulator pump and that drains it a little bit. After your next drive, if it's parked in a secure place, open the hood before you shut it off and then check it later. Or, go in through the passenger side door to unlatch the hood if you can't do the above.

 

Amazing what you learn.

That's something I never considered - that it's the act of opening the Driver's Door which gets the action starting? I can't get in my passenger door - there's a pillar in the way - so I've never tried that. On the odd occasion I have a passenger, I have to reverse out partly.

So I just tried it with the back door. When I unlocked the door 1) the door locks were activated; and 2) the mirrors unfolded - so some electrical drain. BUT it wasn't till I opened the Driver's Door that I heard hums and buzzes.

The other drain is that the interior lamp turns on as you approach the car with the FOB in your pocket, even before unlocking. I suppose if it was unlocked from a distance by FOB, he interior lamps won't turn on.

 

That's the flux capacitor coming to life.

 

Well, that's how it works on my PiP and on the three Gen 2's we've had. I would think Gen 4 would be the same. It's a little frustrating to me that it even pumps when I open the driver's door with the fob no where in the vicinity. I don't see why it thinks it needs to do that. Sloppy programming, I suspect. Like a microwave beeper that keeps going after you open the door.

 

It is possible for a new car to have a 12V that's on its last leg if it's been in the showroom and they allowed it to run down with people opening the doors for long periods without recharging the battery. But I think that's pretty rare.

 

my 6 year old battery still reads 12.7v in the morning

there have been a number of ben 4 failures reported here. too early for sure.

 

Hard to tell - they might have a good reason for it, and not telling us.

I've never had a microwave beeper keep going after opening the door - but I've had babies who continued to cry after changing, feeding and cuddling them.

Mind you - I'm quite frustrated with my new MICROWAVE Oven - it keeps saying that it's COOLING, but things only come out HOT.

 

That's a six month hiatus, not good if the car just sat.

We bought our 2010 in November, 2010. Maybe a month or two post-sale, I noticed the build-date: August, 2009, so 15 months. When we showed up for a test drive, they had it running, "warmed it up" for us. Right...

Anyway, after the drive we decided to buy, and I think to check the Odo reading, we needed to start it up again. It was dead, and their game was blown. We made replacement of the 12 volt battery a condition of sale.

Bottom line, 6 months of sitting on a dealership lot, never charged, never disconnected, will kill most any battery. If you draw their attention to 6 months between build date and sale, you may sway them to come across with a replacement battery. At the least they should give you a gratis assesment, with an electronic load tester.

 

I think it's only the Hybrid battery which will negatively impact economy.

Is that USA or UK MPG - no idea where "central valley" is?

It depends very much on many factors, but here are 3:
1) temperature - either extreme can reduce it - battery runs better above very low temps, high temps mean more A/C load;
2) your driving style - just last night I was driving alongside an old RAV on an almost deserted arterial road - everytime he was jack-rabbit into the distance at the lights, then drove slightly below the speed limit - and I caught him up at the next lights - not good for his l/100km;
3) your commute - longer runs tend to be better l/100 - if I drive 6 days with only 5 or 8km, it's way down, if I have a few days of 25km commutes, it's appreciably better.

 

If you want to know in advance of the dealership, Solar BA5 is a DIY level electronic load tester, they're around $50.

The more I think about it: you've more-or-less just driven it off the lot. Odds are very good it was severely depleted from the get go, from the 6 month sit. Dealership might have already hooked it up to a charger, or even just jumpstart and a drive around. I'm not sure they would be your "friend", more likely to be covering their butts.

 

I don't think you're likely to have a problem at all - my previous car was the previous year's production (2010 build - I bought in Dec 2011). That battery was still going fine in 4½ years, and it had to crank a small diesel. Was winter too when I sold it.