My mk4 has a warning sticker under the bonnet regarding the Li-ion battery. It says in multiple languages " To maintain adequate charge level drive the vehicle for more than 30 minutes at least once every 3 months."
I think this is actually an oversimplification. As others have pointed out if you keep the small 12v lead acid battery charged with a CTEK ,the High voltage battery will probably maintain a charge for much longer than 3 months, and would in any case recharge if you allow the engine start and recharge the Li-ion battery with the engine idling , or a brief drive around the storage yard . Everything looks fine to the owner , and indeed the li -ion battery may remain serviceable for many more years. But as the Honda tech probably realises the real reason for the 30 minute drive is that a Li-ion battery can deteriorate unless it occasionally runs through some rapid discharge and recharge cycles as in normal driving. Just topping it up may not be enough. I dont know but this may also apply to the LI-ion batteries found in plug in hybrids, and full EV's from other manufacturers. Except they would be even more expensive if its necessary to replace them prematurely. If the very expensive Li-ion battery ever needed to be replaced under warranty I think Honda can read the ECU and can tell if the battery did not receive a 3 monthly drive and would refuse the claim. Probably true of other car makers.
I may be over thinking this but you could also run into problems with the warranty terms and conditions . This requires a service to be done at 12500 miles or every 12 months , whichever comes first. And only allows the 12 months period be 30 days early or late. I think if you apply in writing ,in advance, to Hondas warranty administrators (an independent company) they may allow a variation on the 12 month rule (,as long as you dont forget.) Again this is something you may need to check even if you chose another make of car or plug in/EV.
IIRC the salesman briefly mentioned the 3 month requirement, or it might have been on a 'handover video' a dealership put on you tube. It was dismissed as highly unlikely to affect anyone. Maybe not a young working person in a suit. But pensioners may spend winters in the sun or be affected by unexpected periods of illness.
The other storage facility may consider it sufficient to have successfully handed back Hybrids that can be driven away and the owners may never know if the life of the battery has been compromised. No offence to them but with an increasing number of hybrids, and EV's you could perhaps suggest to them that it may help their business if they can advertise a special service that affected cars WILL receive the 30 minute drive, Even if it means they have to call in a driver from a local garage with suitable insurance and 'trade plates'.
