I have LOTS of information on that watch. First, it is a "coffin case", so it uses two # 393 batteries, under that single battery hatch.
But that particular watch - wow, really sorry you bought it. You see, pigeon(John/Gary/Ritchie/Isobel Gibb) first bought a module for it off me. Then he claimed it didn't work and sent all to me. Turns out he wasn't noticing that the buttons both have a sticking issue, generally caused by small blows to the side or from someone somehow marring them on the inside. Virtually impossible to rectify, and the buttons have a different external "hub" size than any of BUlova's other watches, so where to get donor buttons. I told him the same and he told me he wanted his money back. So, I refunded the money, kept the module and sent it back to him with the bottom off since it was going to need to be worked on. He wrote me a nasty-gram for sending it back that way(all parts were in his original plastic shipping container.) So, you bought a watch that wasn't shown working(first mistake), assuming it would be easy to get guts for(incorrect, extremely rare, not like your Polara), in a case that has more issues than a crack whore. And that my friend, is part of the
real world cost of acquisition.

http://www.retroleds.com -
Sales of vintage LED, LCD, analog watches,
parts and gadgets -
repair tutorials & tips
Nov. 2022 - back in business!! BItter divorce is in home stretch, come grabs some great deals, I had to open the safe . . . damn attorneys. piss.