rewolf wrote:635 nm. wrote:rewolf wrote: The seller also told me it used 2 when I asked. Seems like he hasn't opened one yet..
I have come across several modern LED watches that use two lithium batteries hooked in parallel, that way the watch still runs on 3 volts but has twice the life of a single battery. Most pimp type watches that have displays with dozens of LEDs do this. It will work on one cell for several months.
The Tokyoflash blue pimp (maybe others too) does have 2 CR2032 cells, yet not exactly parallel:
1 cell powers the timekeeping circuit, and the other powers the display,
independently. You can remove one and the other part of the watch will still work (doesn't make much sense, though).
Timekeeping hardly sucks any current from its cell (7 microamps, IIRC), so when the display becomes dim after half a year or so, you can simply swap the cells - the remaining charge in the former display cell can still power the timekeeping circuit until the other cell is also drained by the display.
The Pimp style watches I was asked to fix, had some LEDs out did not show any manfacture on the module, and the cells were in parallel, one cell would run both the display and time keeping circuits. After spending almost an hour replacing the tiny surface mount LEDs I realized they were not original Tokyo Flash watches but clones, replicas, rip offs so I returned them with only one repaired. Plus the amber color of the new led was slightly different. I will not support "replica" items.