I checked in ETA's website on the 955.132 movement and from what I can make of it, seems the battery can last up to 94 months. Seems kind of high and couldn't understand all the lingo. If someone could look at it please. I went into customer service then a search on the movement brought up service instructions and manufacture data. It is under the manufacture data. I also believe it says it requires a 395 battery. Again if someone can interpret that information and let me know if it is correct. Thank you.