Recharging IC Cards

Our trip will start in Tokyo and go to Kyoto, Osaka, Hiroshima, and Kumamoto, and then back to Tokyo via Osaka. We'll almost certainly buy a Suica card in Tokyo, but might also buy an Icoco card in Kyoto (don't ask, it's complicated).

If we run low on loaded credit by the time we get to our next destination in this journey, would we be able to recharge / top up our cards at each of these places? If not, then where would we struggle?

Also, would this be possible at train stations, or would we be restricted to the 7-eleven shops? Not that it's a restriction, though, given the plethora of them all over. Just to know where to go to.

Trying to figure out how best to manage the credit on the cards and not get stuck anywhere and need to fiddle around for coins on a bus.

FWIW, we plan to have JR passes, so this is primarily for non-JR trains and buses in the listed cities.

Yes, you can charge your IC cards in any train station in the cities you mentioned, using the ticket vending machines (but generally only with cash). I have personally never topped up my Suica anywhere else.

In case you don't have enough credit on your card to exit the train station, there are usually fare adjustment machines before the gates.

I encountered few stations without ticket machines. They were small ones, for local lines where you directly pay onboard the train. You don't need to worry for your itinerary :)

Train station or convenience stores (not just 7/11) and also some ATM machines. Thousands of places all over the country to recharge your cards.

Thanks to both of you. Appreciated.

We just do not want to get to a place and discover that the card we bought in Tokyo cannot be recharged / used there. I have read some contradictory articles online, but it may be that some of them are old. Hard to tell sometimes, so your guidance is truly appreciated.