Correct Replacement Batteries (NSC WM09N711)

[RyMoeller]

Hello All,

Wondering if anyone has any experience with this particular watch.  It's a National Semiconductor LED watch, model WM09N711, from the mid 1970's.  I have no idea if it works.  The pusher button is missing but can be replaced- but before I get to that, I would like to confirm the LED module still works.  The only problem?  I have no idea what type of batteries to put inside of it!  The battery specification isn't inscribed on the caseback nor the LED module.  I've done a little research so far and have struck out trying to confirm what batteries go into this fine piece.  If anyone happens to know it would be a great help.  Thanks in advance for all responses and Happy Holidays.  

[jdm]

7 minutes ago, RyMoeller said:

 I have no idea what type of batteries to put inside of it!  The battery specification isn't inscribed on the caseback nor the LED module.

Measure the slots and reference from the attached table. I believe that either alkaline 1.5V or silver oxide 1.55 V will not make a difference. To see if it works fit any battery you may have which makes contact.

1_Battery Cross Reference Guide.pdf

[watchweasol]

As advised by jdm  measure diameter and depth and refer to the cart for sizes. They are likley two 1.5v cells  be aware that fitting the cells incorrectly ie wrong polarity can damage the module. The battery guide attached gives you the cell dimensions.

Battery Guide 2018.pdf

[Randy55]

7 hours ago, RyMoeller said:

Hello All,

Wondering if anyone has any experience with this particular watch.  It's a National Semiconductor LED watch, model WM09N711, from the mid 1970's.  I have no idea if it works.  The pusher button is missing but can be replaced- but before I get to that, I would like to confirm the LED module still works.  The only problem?  I have no idea what type of batteries to put inside of it!  The battery specification isn't inscribed on the caseback nor the LED module.  I've done a little research so far and have struck out trying to confirm what batteries go into this fine piece.  If anyone happens to know it would be a great help.  Thanks in advance for all responses and Happy Holidays.  

Check out the 4th photo in this listing. I think you will get all the info you might need from this..

https://www.ebay.com/itm/124972474298?hash=item1d18f09fba:g:4OgAAOSw~eNhdveu

[JohnR725]

Typically for LED watches the batteries will be large as they consume a lot of power. The picture in the link above looks like a 386. At the link below it looks like a 357 which are both identical in diameter but very only in height.

 

http://www.crazywatches.pl/novus-led-1975

 

[RyMoeller]

Wow, thanks for all the great responses!  I used the charts provided and came to the conclusion the 386 is probably the correct battery (which is what I was leaning towards before I asked the question but my methods were based on more ignorant assumptions) The photos @Randy55 linked provides the proof.  Can't wait too see if I can get this thing to light up!

Thanks again for the help and the documentation- it will certainly come in handy in the future as well!