12v battery (hybrid) runs low after sitting for a week

[Cordoc]

Adding an alternator won't have any benefit unless you're drawing more power than the hybrid motor/generator can supply.

Also given other threads it's not clear that all 2025's are getting the alternator.



12.2VDC after a 30 minute drive is a bad battery (or bad charging system) regardless of AGM or lead-acid. Given the amount of self-discharge in two days it's likely the battery unless there's some significant parasitic draw.

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[Cordoc]

I have a 24 Trailhunter with no alternator, I have never had a battery problem.
In Jan I left the country for 2 1/4 months and went to the garage, and it started in 1 sec flat.
Any problem with starting after a few weeks should be investigated since it is not supposed to happen

 

[SnowmanJPS]

This is also the battery that is in my '24 OR hybrid. I carpool every other week and travel, so my truck sits for a few days and intermittently a week or so. Knocking on wood, I have yet to see an issue.

Same battery as my 25 pro

 

[max911]

Just a follow up to my truck getting a new (12v) battery from the Toyota dealership.

Was away for about ten days on a roadtrip in my convertible.
Returned home and the truck fired up perfectly when i tried it this morning.
Voltmeter stays at midpoint (14v) Whereas before it would drop down to 12v after 5 or 10 minutes of driving with the original battery.

I'm thinking there is probably enough of a sample size by now that Toyota must be aware that there was a bad batch of batteries that are failing in the first months/year.

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