Power Source: 12v

[MMCGARAGE]

For the next three months, I may be unable to take my beloved CH-R out of the garage; what is the recommended procedure for a 12 volt battery?
Just let it deplete on its own and recharge it when you get back.
There can be issues with the management system if you disconnect the battery from the vehicle.

Another choice would be to use solar power or a comparable trickle charger—

[IMINGAR55]

Method of trickle charge (this is just my view; other people could have more practical suggestions)

Otherwise, have someone run it for 30 minutes once every two weeks.

[Loonie4cars]

You may simply begin using the remote start feature on the Toyota app every two weeks.

[Top-Maverik-Racer]

For both choices up there, it's a one-plus.
From what I've read, a Ctek battery conditioner is a popular choice, and I know a lot of people who use one, particularly while leaving their vehicles parked for an extended period of time.

[ChristousPapous]

Connect it to a smart charger like a CTEK - it's an obvious choice if your garage has electricity

[EvestineBeetle]

The old-fashioned manner is the way to go if you can't use a trickle or remote start.

[ELDORADO4TRUCK]

While away for a month (in a safe garage, so the alarm wasn't necessary), I disconnected the battery and everything was OK.

[ELDORADO4TRUCK]