The general principle is true, but does Canon have any special edge in battery design, over the better 3rd-party battery makers? We aren't talking lenses, flashes, etc.
A person never having to have cleaned a battery contact at all may just demonstrate how low the humidity is where their batteries typically spend their time.
In the summer, it gets pretty humid here in NY, and I put spent batteries in a pant pocket so that I notice them there and remember to recharge them. I have typically owned 2 aftermarket batteries to every Canon battery, and yet, I have only found myself having to clean the contacts on the Canon batteries, and this is in recent years with relatively new Canon battery form like the ones used in the 5D2 through the R7, with their very small contact area (thin slots). I use a piece of thin cardboard in the slots to clean them.
I doubt any camera manufacturer makes their own batteries as that's a specialized industry.
NY is a large enough state to have local variations in humidity. It will be more humid near the Great Lakes. Long Island will be humid too.
So...Long Island gets to maybe 60% humidity?
https://weatherspark.com …ear-Round#Figures-Summary![]()
Omaha actually tends to be more humid.
https://weather-and-climate.com …,United-States-of-America![]()
My batteries are in the camera or in a pocket in a backpack.














