watch battery

starving_artist

Not sure which forum is best for this but - I have a Mondaine swiss railway wrist watch which needs a new battery. In the past I have tried numerous jewellers but they have always said they don't handle these watches so I always end up taking it to Debenhams on Oxford Street. Last time they charged £18 :eek: so I was wondering if anyone can suggest anywhere better in central London? I'd also have a go at changing it myself IF it is really, really straightforward but then I also don't know what battery it takes.....

greatgimpo

Pity you didn't keep the old battery as a pattern.

bcl999

Surprised about this as i had no problemgetting a new battery fitted to my Mondaine at the cheapest place (independent jeweler) in a small provincial town. i think I paid £3. Timpsons wanted £9 if I remeber right.

Changing it yourself is possible but you need the right tool to open and close the back.

CallaVandy

Put its old battery out... Read the serial or product number of battery and search it on the Internet.... Check here maybe you could find some information about your watch's battery...
mondainewatch[dot]co[dot]uk/mondaine-swiss-railway-watch-evo-giant.html

Joe_Horner

They use a 371 battery ( also known as an SR921SW ). The movement is a Ronda 509, which is a straightforward battery change if you can get the back off.



If you look at the left edge of the battery, there's a lever with a small hole near its end which overlaps the edge of the battery slightly.

Push that lever away from the battery, just enough for the battery to pop out (it will pop up once clear).

Be very careful when doing this that you don't slip and hit the coil (the orange part in the left) because you'll kill the movement if you do. Not the end of the world, but would turn a cheap battery change into a relatively expensive repair (I'd be charging about £17.50 for a coil or £35 for full movement replacement)

Once the old battery is out, insert the new one by dropping it into place with its right edge under the "lip" of the plate (see how the old one was sitting). Press down gently on the battery while pushing the lever out of the way again (same warning about slipping!) then letting the lever back into place to hold it.

The model is only splashproof, so don't worry too much about water resistance - you shouldn't be getting it wet deliberately anyway! There's a rubber O ring that seals the back, make sure that's in place and not obviously damaged as you put it back together and it should be fine.

On the subject of the battery itself, if you do decide to DIY it then please get a proper branded silver oxide watch battery! Renata (my preference), Maxell, Sony and Seiko are all decent brands, other named cells are usually ok.

The cards with lots of sizes of alkaline button cells are very tempting and seem like great value, but they will leak and they will destroy the movement with acid if you leave them in there more than a year or so - even less if you're unlucky!

starving_artist

Joe_Horner wrote: »

They use a 371 battery ( also known as an SR921SW ). The movement is a Ronda 509, which is a straightforward battery change if you can get the back off.



If you look at the left edge of the battery, there's a lever with a small hole near its end which overlaps the edge of the battery slightly.

Push that lever away from the battery, just enough for the battery to pop out (it will pop up once clear).

Be very careful when doing this that you don't slip and hit the coil (the orange part in the left) because you'll kill the movement if you do. Not the end of the world, but would turn a cheap battery change into a relatively expensive repair (I'd be charging about £17.50 for a coil or £35 for full movement replacement)

Once the old battery is out, insert the new one by dropping it into place with its right edge under the "lip" of the plate (see how the old one was sitting). Press down gently on the battery while pushing the lever out of the way again (same warning about slipping!) then letting the lever back into place to hold it.

The model is only splashproof, so don't worry too much about water resistance - you shouldn't be getting it wet deliberately anyway! There's a rubber O ring that seals the back, make sure that's in place and not obviously damaged as you put it back together and it should be fine.

On the subject of the battery itself, if you do decide to DIY it then please get a proper branded silver oxide watch battery! Renata (my preference), Maxell, Sony and Seiko are all decent brands, other named cells are usually ok.

The cards with lots of sizes of alkaline button cells are very tempting and seem like great value, but they will leak and they will destroy the movement with acid if you leave them in there more than a year or so - even less if you're unlucky!

Wow! Thank you so much for taking the trouble to reply in such detail!

Joe_Horner

Happy to help - with you in Central London it's unlikely I'm losing myself a customer on Anglesey, and it all helps to fight the (frankly outrageous) prices some of the national chains charge*





* often for no better technical service than you can do yourself!

booter

Be very careful when doing this that you don't slip and hit the coil (the
orange part in the left) because you'll kill the movement if you do. Not the
end of the world, but would turn a cheap battery change into a relatively
expensive repair (I'd be charging about £17.50 for a coil or £35 for full
movement replacement)

A friend told me this recently, which is something I didn't know (which is probably why I get through a lot of watches ) But then ensued a debate about whether the movement was killed if you hit the coil with a finger vs a screwdriver (or butter knife ) Can you clarify - does the watch die if you hit the coil with anything? (There's money on this - I could be a fiver better off, depending on your answer :rotfl:)

Joe_Horner

booter wrote: »

A friend told me this recently, which is something I didn't know (which is probably why I get through a lot of watches ) But then ensued a debate about whether the movement was killed if you hit the coil with a finger vs a screwdriver (or butter knife ) Can you clarify - does the watch die if you hit the coil with anything? (There's money on this - I could be a fiver better off, depending on your answer :rotfl:)

It depends whether you damage the windings or not. Just touching it (even with a screwdriver) won't kill anything but the wire is very thin so more often than not a screwdriver or tweezers - or butter knife! - will cause damage because they cut the winding.

Finger tips are unlikely to harm it unless you deliberately rub it hard, but if you scratch it with a fingernail then you can do as much damage as a metal tool would.

Hope that's the answer you were looking for



If you look carefully, any damage to a coil is often visible as a bright copper-coloured mark against the (usually orange) insulation. If it does happen you can sometimes save the situation using conductive silver paint dabbed on over the damage but the paint is stupidly expensive unless you have it anyway!

booter

Thanks Joe Horner - I'm now richer by £5.00 :T (my friend was adamant that even touching the coil with a feather would "short out" the watch) and more if you include the amount of money saved by changing my own batteries without destroying watches. (Oh and I'm nowhere near Anglesey, so no lost custom for you here either:)) Thank you so much