Power up! Bring extra plugs and cables! Rooms may be nice, but many have only a plug or two that functions properly. Bring USB plugs and multi-prong plugs for all your devices. Cables might be difficult to replace or find in Cuba so if the gadget is essential, bring a backup. Cuba uses the same wall plugs as the U.S. so that’s a relief, no adapters needed for U.S. travelers. The Electric power shut off a few times (for several hours) when I was there, so bring a flashlight or have a candle and matches you can locate in your room.
You can see the whole article published in Journeywoman here: http://journeywoman.com/gfc/practical-tips-to-prepare-for-your-solo-trip-to-cuba.html