I also tried to go out on the web to find out what kind of power would be used in that area -- and yes, it was going to be exclusively 240 volts in all of southern Africa. I didn't worry too much about that, since I'd been conscious that most modern electrical wall warts were dual voltage. I rechecked. Yes, our Apple laptops would work off 240. My battery chargers would also. The only issue was whether the plugs would fit the outlets, and I had two different universal plug kits. One by Samsonite. Surely I'd be covered.
We arrived in Capetown, checked into our first hotel room. None of the plugs fit.
It seems that 'universal' doesn't mean southern Africa. After leaving Capetown and arriving in Namibia, I began to realize it wasn't just South Africa, but the countries near it also used a different plug. Look at the white plug in the photo with its three large round contacts. It's huge.
We limped by using the universal bathroom outlet for electric shavers, but it wasn't always reliable, and with two laptops and two different battery chargers to service, it was difficult. But going through the airports, I finally discovered the right adapters.
Several places sold these. There were two kinds, "The Visitor" which I bought and allowed us to connect to SA-style outlets, and "The Traveler" which was for SA residents and allowed them to survive the the rest of the world. I'd advise any tourist to be on the lookout for them as they travel through the Johannesburg airport.
In Zambia, we actually had use for the universal adapters I'd bought, since they used a different style outlet, but I'm definitely hanging onto my SA adapters. I just might go back.