Buying a giant battery for the next blackout or off-grid adventure can be daunting, especially when hundreds or even thousands of dollars are on the line. Get it wrong and you’ve either spent too much money for something you’ll never use or discover that you didn’t buy enough capacity to keep your most important devices running. To get it right, you need to become intimate with the watt-hour (Wh).
The watt-hour is a measure of capacity, or how much electrical energy a battery stores. If…
