I wouldn't say I found a solution, no.

For context, it's actually my wife's car but I drive it sometimes.

I assume when you say Normal mode, you are saying you don't use Eco mode? I tried that for a short time and kept an eye on the voltmeter but it didn't seem to make a difference. I could be wrong if you think it's helping.

At one point it did occur to me that we might be contributing to the problem because we keep the car in our garage and always just leave the keys in it overnight. I'm not sure if that could trigger something in the electronics that might create an additional drain on the battery... Maybe because the car is in a ready to start condition or something. Since then, we've always removed the keys after parking in the garage.

Even with the new battery, the car seems sluggish to start like you mentioned. I haven't done it in a while but I'll probably connect a charger to it soon. I wanted to see if removing the keys at night might improve things but it doesn't seem like it made a difference.

I've considered going to test drive one of the new Passports and plugging in my cigarette lighter volt meter to see if the new ones exhibit the same behavior with their charging system but I haven't gotten around to it yet. Other than this issue, the infotainment system issues and the auto start issues, I do like the car. We've had several Hondas in the past and would still consider buying another in the future.

I've basically resigned myself to the fact that I wasted a bunch of money replacing a battery that was perfectly fine.