In storage

I believe the manual has suggestions for extended periods of storage...maybe check that out.

 

For three months, I'd think about disconnecting the -ve terminal on the 12V battery. The traction battery will be fine.

Note that you won't be able to easily open the hatch once the battery is disconnected, so it would be useful to have a "boost battery" to connect under the hood on the boost terminal so you -can- open the hatch in the normal way. You can purchase a boost device for $20 to $50. They often also contain emergency lights and a tire pump.

Or, have someone start the car (put it in "ready") for a few hours once each month. Not in a closed garage, as the engine will run.

Third option, get a "battery tender" and connect it to the car while you are gone. You'll need 117V nearby for this though.

 

If you feel comfortable, you can also just loan your car out to a relative or a not-for-profit organization you trust. One more hybrid on the road is one less regular car off the road, and that is good for everybody. Donating your car's usage to a not-for-profit organization may also be tax deductible, even if just for 3 months.