Don't buy cheap alkalines, they leak. If the device isn't being used on a regular basis then remove the batteries after using it and don't store them in the device. Buy some good rechareable NiMh batteries like Eneloops, they keep a 75-80% for a year if they sit unused, and get a good smart charger. The up front cost of buying rechareables and a charger will save you money in the long run compared to buy cheap and shitty alkalines