Ever wonder how much you’re paying to keep your rechargeable camera batteries juiced? The answer: probably around a buck or two a year. Researcher Baskar Vairmohan of EPRI conducted a study to determine the effect of popular gadgets on our nation’s power grid, calculating the annual electricity costs of various devices. He found that an iPhone uses $0.25, an iPad uses $1.36, a 60-watt light bulb uses $1.61, a laptop uses $8.31, a desktop uses $28.21, and a fridge uses $65.72. Camera batteries probably fall somewhere between an iPhone and a light bulb, meaning they’d cost less than a Starbucks coffee to power for a year — though you still need to pay for the (often pricey) batteries themselves.