It is hard to give a single response to the question “What kind of battery do I buy for my hearing aid?” because hearing aid types and styles vary widely, and so do the batteries used to operate them. If you already have a hearing aid, check the device’s manual or the hearing care professionals who sold it to you to verify the right battery type and size. If you’re still looking for a hearing aid and trying to choose which style is best for you, you might wish to do some comparison shopping to assist you in your selection. The explanation for this is that hearing aid batteries differ in price and in battery lifespan, and so an estimate of how many of them you’ll need over time can influence your choice of which hearing aid to get.Fortunately, hearing aid battery packaging uses a standardized color coding scheme. The sizes are all standard across manufacturers, so the color on the package is a dependable indication of the battery size and type.The 4 most common ones are:Size 10 / Yellow – Size 10 hearing aid batteries are identified with a yellow color code, and are currently the most extensively used, being used in a large number of In-The-Canal (ITC) and Completely-In-Canal (CIC) styles; due to their smaller size, they have an approximated battery lifespan of about 80 hours.Size 13 / Orange – Size 13 batteries are frequently used in In-the-Ear (ITE) and Behind-the-Ear (BTE) hearing aids, and have an average battery lifespan of 240 hours.Size 675 / Blue – Size 675 is always coded blue, and is typically found in Behind-The-Ear (BTE) hearing aids and in selected cochlear implants; the 675 batteries are fairly large and have the benefit of a long charge, lasting as much as 300 hours.Size 312 / Brown – Brown corresponds to Size 312 batteries. Size 312 batteries are on the smaller end of the spectrum and typically maintain a charge for about 175 hours. These batteries are commonly found in In-The-Ear (ITE) and In-The-Canal (ITC) hearing aids.These 4 battery types cover most hearing aids, however there are a few exceptions that necessitate alternative batteries. Most in-store providers of hearing aid batteries advertise and stock the more common battery types above, however if you inquire about a specific type, they can usually get it for you.Before stocking up on batteries, remember to read the manual that came with your device to make sure it doesn’t have rechargeable batteries; if it does, you need disposable ones only as back-up. To keep your batteries fresh and fully charged after you purchase them, always store them inside at room temperature and in their original, unopened packages.