Required batteries for Accutrons, all use today's silver oxide batteries instead of the old, unavailable mercury batteries. Today's batteries are .2v higher in voltage so can make an accutron run a bit fast until they are rephased (adjusted) according to Bulova procedures. I do that with service.
214
387S, 394** (with a reused plastic ring from the old battery, Accucell 1
218
344, 350, Accucell 1
219
344, 350, Accucell 1
2210
388, 329, Accucell 2
230
344, 350, Accucell 1
224
344, Accucell 1