cristalonic solar quartz

[digibloke]

http://www.scienceandsociety.co.uk/results.asp?image=10308536

I've been after one of these for ages and finally picked one up last week. Apparently it was the first commercially available lcd solar powered wristwatch. It's a cracking piece of kit and it's running and setting fine under a 40w light bulb. Problem is I have no idea what kind of battery to put in it (I'd like to be able to wear it at night as well).

The Battery compartment is perfect for a 357 - but I'm presuming that I need a rechargable battery for it. Does anyone know what I should be searching for as "357 +rechargable" isn't getting me anywhere? Also would NiCad be the right thing for this watch?

One other thing. The circuit board contact for the battery has a "+" in the middle of it. I'm assuming this means "+" side down. Or am I misreading the clues...

Any help or tips at all with this would be very much appreciated

[digibloke]

I forgot to ask...

Do I run the risk of damage to the battery or watch if I just plonk a silver oxide 357 in there?

(solar power really isn't in my ballpark...)

[bucko170]

Nice watch.

The link is to a list of rechargeable batteries for sale, the details include dimensions so maybe you could match up the existing battery.

http://www.master-instruments.com.au/ca ... _Cell/1177

The batteries are not to expensive, (I brought a couple when I was playing with the Synchronar's.) There are other suppliers I only choose that supplier as they gave dimensions, a few others -

http://www.batteryspace.com/index.asp?P ... tegory=706

http://www.made-in-china.com/showroom/j ... -60K-.html

http://www.cellpacksolutions.com/Search ... hall=varta

http://www.rfidbackup.com/Varta/Varta-40H.html

I would say + to +, can't think of one that i've had that was any different.

I would say take your time to get the right batteries, why rush and risk damaging the watch by using the wrong batteries?

[Old Tom]

The rechargeable battery that was the same size as the 357 was the SR44R- this was available till very recently as it was still used in a number of other "modern" solar devices (eg the Cateye Cyclo Solar bike computer). Production ceased about two years ago so it might still be possible to find stock of these around, somewhere! Beware that a number of sellers say they have SR44R cells but ship plain old ordinary alkali or Silver oxide batteries.

Using a non rechargeable in your Cristalonic is perfectly OK and is very unlikely to cause harm even with charging current applied- I prefer to use ordinary alkali button cells rather than Silver oxide cells as they definitely have better limited "recharge" characteristics. The + marking almost always means place the +ve cell connection here, putting a 1.5volt cell into an LCD watch the wrong way round shouldn't cause any damage (unlike LED watches), just somewhat excessive current drain and non function.

[bucko170]

According to this seller the Varta V40H can be used to replace the SR44R?

http://server6.gs-shop.de/200/cgi-bin/s ... eterID=287

I don't know if that information is correct, hopefully Old Tom or one of the other forum members can advise you further, but if it is compatable it can also be found in the links as given previous.

Failing that this company states that it will custom make obsolete batteries, don't know how much they would charge though.

http://www.cellpacksolutions.com/custom.asp

[digibloke]

Thanks very much for the help Bucko and Old Tom. I've been looking for some SR44R batteries and (as Old Tom says) there are a lot of stockists selling ordinary silver oxide cells to replace these. That varta V40H looks promising. It's a little too deep but that shouldn't be a problem as the negative connection is a screw down retainer to the module and there's a bit of space between that and the case back. (I see that it's only 1.2v though - wonder if that would be enough?).

For the time being I've been unable to resist putting a 357 alkali battery in there to see if it's working and it's running perfectly (and living in Scandinavia I don't have to worry about charging it at this time of year if I stay indoors between 11am and 3pm...)

I'm really looking forward to going to work on the case and band now. It's a big chunk of stainless and it's going to look great with a bit of TLC.

[rewolf]

SR44/357 size D=11.6mm, H=5.4mm

Selling Varta V40H NiMH battery, 4pcs for 12.95€:
http://www.akkushop.de/varta-v40h-nimh-battery-55604-coin-cell-mh-13654-4-stueck-p-2516.html
http://www.akkushop.de/varta-4v40h-nimh-battery-55604-mh-13654-ohne-loetfahne-p-7905.html
According to that seller, size is 11.5mm x 5.35mm - perfect fit

V40H on Varta site:
1.2V 43mAh 11.5mm x 5.35mm
http://www.varta-microbattery.com/en/oempages/product_data/poductdata_types.php?output=search&context=orderno&searchvalue=55604201012

So if a 357 fits, a V40H should also fit.

[retroleds]

One other thing. The circuit board contact for the battery has a "+" in the middle of it. I'm assuming this means "+" side down. Or am I misreading the clues...

As a confirmation, always look if one battery port bottoms out with a sharp corner compared to the other. Sharp cornered side is + down, side with a chamfer/curf/bevel in the corner is "-" down. Sometimes it's the only clue. And depending on the design of the contact, tht bevel in the bottom can stop a battery put positive side down from make fatal contact if put in the negative[wrong] port.

PRobably 90% of watches, when viewed frgom back with 12 oclcok up(away from you), will have positive down on the right, negative on the left. Contrary to the old plumbing saying of," hot on left, cold on right, stuff goes down the middle".