Battery Drain After Sitting for 3 days

I have a 2019 stock (I haven't added any electronics) TRD-Off road that's been sitting in my garage for the past 3.5 days. It's cold out (about 20F) and I decided to check the battery voltage. I was surprised to see it at 12.2 volts at the battery terminals. Even with the cold this seems way too low. This is about 50% charge which makes me think if I let it sit much longer I might damage the battery or it might not start.

I occasionally go out of town for a week and need to park at the airport. Does anyone know if these trucks can sit for a week without the battery going dead?

 

Its hard to say without testing your battery. I will say that my truck can sit for two weeks during the summer and fall because I am riding my motorcycle then. I will drive the truck once every couple weeks. However, if you have a weak or bad battery, your results will vary.
So, the answer is, yes the truck will be fine, but what condition is your battery?

 

Battery VOLTAGE for our trucks is 12v...so, your battery is hella great for 12.2volts at rest.

 

The truck (and the battery) are new as of July. It's been normal driving so I shouldn't have degraded the battery. Good to know you've let yours sit for a few weeks without issue. That kind of thing is difficult to test since I use mine fairly regularly.

 

12.2 is fine. What on earth are you expecting?

Open circuit voltage doesn't reflect state of charge or battery health.

 

Typically car batteries measure 12.6V at 100% charge. This truck measures measures 12.65V in the summer an hour after I turn it off. It drops a bit (~0.1V) by morning but still stays close to that 12.6V number. I haven't been able to check it after sitting for a long period of time but per most of the battery charts (Google for "battery voltage vs charge") 12.2 is arround 50% charge (albeit that is usually measured at 80F).

 

Its a 12v system, but a good battery is 12.6v.

 

>12.6 is full charge. 12.2 is about 60%.
Are you sure you didnt leave a door ajar?

 

Looking for issues?

 

All the doors were closed and there wasn't anything running. I don't think anything's wrong. The only reason I checked the voltage was because I know some of these newer cars have electronics that continuously draw a small amount of current and can eventually drain the battery (dad had a Chrysler that did this). These Tacomas have a pump that runs an emissions / pressure test that runs nightly. I would hope it would only run once at some point after shutting off the vehicle and not every night if you aren't driving it. Just wanted to find out what was "normal" and if it sat at the airport, would this cause an issue or not.

 

I just checked mine the other day after sitting a few days, it was 12.18V and fine.

 

You could always get a jumper pack to keep in the truck. They are not that expensive, and some have flashlights and also usb charger ports if needed.

 

No.
12.2 is actually 55% charged
Fully charged is at least 12.6v

 

Haha ok fair, I won't argue the corrections.

Perhaps just replace the battery with an upgraded one with higher cold cranking amps and you will be fine with everything else ...

 

Mines sits for months in -20c. Starts up easy after two months of no starting, no battery issues ever.

 

Your truck is fine, your battery is fine don't stress. As for two week layover, I can't say I never go more than a few days I guess mainly because I hate flying and rather drive in my truck.

Check the battery water lvl, put in a trickle charger for at least 24hr and call it a day.

Oh and just one more thing, get you a jump pack to keep in your truck. You never know when someone will need a jump and you don't want to use your truck.

Cheers $59.99

 

You're exactly right.
Battery will sulfate once it's discharged. An alternator cannot 100% fully charge a battery. You need a "battery charger".
People who don't drive their vehicles much, will need a trickle charger to keep battery fully charged.
People here who complains of battery going dead less than a year or 2 probably falls into this or off the lot battery was already sulfated.
I have a Battery Minder that charges and desulfates.
Even the truck that had 2 miles on it, I hooked it up to the desulfator. At 80% it started desulfating.
I never had a battery going dead less than 5 years.
AGM is the better way to go as it can be discharged several times .
Every once in awhile I hook up the charger to our vehicles to go through the cycle.

 

If you can show me a modern vehicle that sits at 12.6v for 3 days I'll mail you a cookie.

You are over analyzing. Batteries discharge slowly, its what they do.

You have a smart key on a modern vehicle, its probably draining 60mA all night, you can't expect it to stay at 12.6v epsecially without long drives to ensure full charge.

Batteries are designed to operate out of ideal charge, there's nothing wrong with any number above 12.0v cold.

Next post a pic of your rusty diff and complain about that.

 

I agree with this. Always put my truck on a charger when I’m on vacation for a few days or a week or more, just 30 minutes to boost it and it’s good to go. Also would put my Harley on a trickle charger or (battery tender) during the winter months