Interesting that the documents/links are for "pre-delivery service" (PDS) - meaning they're intended for dealer use before sale, rather than for the consumer. Seems like Toyota takes into account that hybrid vehicles can sit on dealer lots for a while, and require special checks to ensure battery quality and mechanical health. Would be nice if this type of information was communicated as a standard to all consumers.

The PDS that I've seen from Honda aren't nearly this detailed. I hope Honda internally has a detailed version like Toyota's; but given some of the 'battery failure' issues reported already among forum members, methinks Honda is lacking in this area...

Well, I read everything I could and talked to everyone that claimed to know anything about whether we could charge or tender the 12v battery. Every source said no and claimed that if I parked the car for 2 months when I'm in Florida it wouldn't hurt anything. I'll find out soon. I parked my 2019 Insight Sept 27 and hope to get back in it about November 23. We will see how good that battery really is. Cross your fingers folks.

Looking forward to read about the outcome.

I live in rural Minnesota, and need to store my 2019 insight for the winter in a well ventilated outbuilding through much of the winter. Once the heavy snows come I won’t be able to drive the car until spring. I have two questions:
1. Can I use an AGM float/maintenance charge like the following to keep the 12v battery charged?
Battery Tender Plus 12V, 1.25A Battery Charger https://www.amazon.com/dp/B00068XCQU..._XM86DbEFSXSET

2. Will I be able to keep the HV battery alive and well by just starting the Insight once per month for 30+ minutes. I can do this at around 3000 rpm if needed, and can open large doors on the building to keep things well ventilated.

1) That charger should work well with our AGM battery.

2) It should be fine, if you have enough room in the building, I'd pull it forward and backward a couple times to make sure the drivetrain stays well lubricated and to prevent flat spots on the tires from developing.

Obviously if you have a nice weather day, I'd take the car out for a short drive. (Also be sure to check for rodents and other animal debris, and hope they haven't chewed on anything.)