Battery Life for an LCD Watch

[Watches]

I'm importing a small quantity of LCD watches from which will have the battery preinstalled and active. The watches will arrive by ocean freight from China and will be in transit for 20-35 days.

I have the option of a Japan-made Maxell LR41 battery (expensive) or a China-made equivalent (less expensive by $.15 to $.20).

My concern is the life of the battery. Would anyone be able to assist me in a way to estimate the life in days or hours?

Thanks.

 

[Klaus]

This is as question akin to asking "how long is a piece of string" .
It REALLY depends on the watches current draw AND battery capacity.

For example, I usually buy the really cheap ($5.95) wrist watches as I tent to scratch and ruin good watches while at work. These watches *always* failed from a broken wrist band. I had some with buttons breaking off but the thing still keeps ticking on, for many years, while lying on my work bench. One just ran out of battery, after about 10 years! And 8 of them without a strap to wear it :cry: I left it lying there just to find out how long they would run.

I have no idea where exactly my cheap watches were made but from the "funny" instructions with them I would say somewhere in a third world country.
I would think that the button cells should last the time until selling the product
:wink:

However, I have also seen cheap Chinese dry cells (in calculators) and also "sealed" lead acid batteries in spotlights, that were leaking all over. Not a pretty sight when that new gadget already has corrosion problems inside the battery compartment and nearby circuitry.
Klaus

 

[Watches]

Thanks for the info and your experiences with the batteries that wouldn't die! Do you know how to determine current draw?

 

[Nigel Goodwin]

Thanks for the info and your experiences with the batteries that wouldn't die! Do you know how to determine current draw?

You measure it with a meter!.

 

[tansis]

The exporter or maker should be able to provide a figure for the lifespan of the battery, based upon "average" use, if the watch has a light and you only check the time in the dark it will use more power.
Typical lifespans for coin cells in these sort of applications is 10-14 months
other factors such as temperature and humidty also play a part.

Being totally ruthless , buy the cheapest battery and sell them quickly.

How does the price of a locally bought replacement battery compare to the retail price of the watch?

 

[Watches]

Thank you very much for the info and advice. Local battery at retail is a couple of dollars. I was most concerned with the battery dying prior to the watch being sold (it's in a blistercard) but 10-14 months is good. Exporter said about 18 months and their is no light to drain battery.

We should be OK.

Thanks again.

 

[zevon8]

May "analog style" watches with hands, are shipped with the stem pulled out to the adjustment position, this stops the watch, and means the battery should last for its shelf life.

Digital watches do not have such a feature, so generally are shipped "running"

 

[Jimbojet]

i got a free digital watch in a Rubio's kids meal about six years ago. It had a Chinese LR41 battery, and it just ran out of juice the other day.

I opened it and measured the current the watch draws from 1.5V, it was about 1.6µA. I didn't have a precision low-current meter, so this might not be an accurate number, but it is probably within 20%.

 

[audioguru]

The cheap Chinese batteries at The Dollar Store are obviously leaking all over the place on the rack before even being sold.
Maybe they spent a year on a boat then another year in a warehouse then another year in the store.

American and Japanese batteries last a much longer time and always work perfectly when purchased.

 

[Hero999]

I don't think you read his post properly, the battery lasted over six years - older than this thread!

 

[audioguru]

Last week I went to a display of what the Police dept are doing to reduce crime. They simply jail all the African-American criminals they find.

I was given two Chinese scanning FM radios, two Chinese clocks with thermometers and two Chinese calculators.

One radio played for about 20 seconds, started to motorboat then went dead. Its battery was leaking and died quickly. The other radio did not work until I replaced its battery. Its battery was not leaking but was dead.
They sound awful and pickup only strong local stations. They have the size and shape of a small egg and have a 1" shrieker instead of a speaker. Their headphones sound worse.

The clocks and calculators work fine. Their batteries look good but might fail tomorrow.