Battery Life.

[Kansasmike]

I will be out of the country for 69 days, my Yaris Cross (71 Plate) will be in my garage, how long will the charge last, not long I imagine. As such should I leave it unlocked so the alarm does not go off when Battery is being re-charged.

[TonyHSD]

Hi, 

your best solution is to fully charge your 12v Battery either with external charger or via ready mode for 60 minutes and disconnect the negative terminal and leave the car unlocked prior to your travel. 
There is another way of disconnecting a main fuse so the car is disconnected from 12v supply but let others talk about it as I haven’t done that myself. Otherwise if you leave the car just like that after that many days you will not be able to start it on your return and most likely you will need to buy a new 12v Battery. 
 

[dash]

Solar panel positioned on garage roof should maintain Battery level (30W to be on safe side)

 

[MikeSh]

For that long just disconnect the Battery. It won't lose any significant charge like that, so charging it before leaving is optional but preferred if you have something to do that easily.

Leaving any sort of charger connected unsupervised is a risk. Eg, a rodent chewing a cable could cause a short.