No problem, just wanted to say i've had the watch for 8 years and have never changed the battery. just wondering how it last so long?

I am assuming you are reading the battery charge correctly. If so you need a new rechargable battery. Special battery so it is a little expensive. Make sure the person knows it is a "rechargable battery" you want. A regular battery will not work properly or recharge.

On average, I've found that analog wristwatches that use a silver oxide (or alkaline) battery last about a year after a fresh battery has been installed. Digital watches, because they have no moving parts, will typically last longer on a set of batteries if you're not using the alarm or backlight function. Watches that use lithium batteries generally last two years or more between battery changes.

Based on your model watch, I would guess that your battery has run down too far to power the movement. A fresh battery will probably fix your watch. Hint: in the future, if you aren't going to wear your watch for a while, pull the stem out into the "set" position. That will stop the movement and extend the life of your battery. When you want to wear the watch, simply set the time (and date, if you have a date window) and push the stem back in.

If you have a Fossil FS4337 Chronograph, shaking the watch shouldn't be doing anything other than exercising your muscles; the movement is a battery-driven quartz movement whose movement is controlled only by whether the stem has been pulled out (stopping the movement and saving power) or whether the battery still has enough power to activate the stepping motors that move the watch hands. Based on the symptoms that you've described, I would suggest that it's probably time to change your watch battery.

Often, when a watch battery is running low but isn't completely dead, pulling the stem into time-setting mode will stop the movement and permit the battery to "rest," giving it (briefly) a bit more reserve amperage to put out when you push the stem back in. That's how you can sometimes get a quartz watch to run for a few minutes after the battery appears to be dead. That may also be why your watch has started running again after you've set the time and date.

Fossil analog quartz watches tend to use silver oxide (usually #377 or #379) batteries instead of longer-lasting lithium batteries. In ordinary use, I would expect a silver oxide battery to provide between 1 and 2 years of service before it needs to be replaced. I can't remember if Fossil chronographs (which also use quartz movements) use a silver oxide or lithium battery. Lithium batteries often provide an additional year or two of service in analog watches, compared to silver oxide cells; digital watches using them supposedly may last as long as 10 years with a lithium battery, assuming you don't use the backlight or audible alarm functions. Note, however, that these batteries are different sizes and different voltages, so you can't substitute one for the other.

Finally, none of this advice applies if you have a Fossil watch with a true mechanical movement in it. In that case, gently shaking the watch may spin the winding rotor enough to start the watch back up again. However, an even faster way of winding those watches is to use the winding / time set crown to wind the mainspring directly instead of relying on the geared-down action of the winding rotor. Automatic watches can bind up if they are not used for a period of time; the lubricating oil used in some of the pivots can harden--or at least provide enough resistance that the movement may require more initial force to start running than to continue running. That behavior usually indicates that it's time to have the mechanical movement cleaned and re-lubricated.

The vast majority of Fossil analog wristwatches take either a #377 or #379 watch battery. The #379, being slightly smaller, is somewhat more commonly found in women's watches than in men's watches, but I have seen both types used in men's and women's watches alike. However, the Fossil CH2473 includes chronograph functions, which means that you can have multiple motors inside the watch running simultaneously. As a result, it's possible that this watch will require a different / bigger bigger. However, if it's not one of these batteries, or even if it takes a 3-volt lithium battery instead of a 1.5 volt watch battery, it will still be something pretty mundane.

In general, common batteries like the type I expect you'll find inside your watch are commonly found at many drug stores, jewelry store counters at places like Walmart and Target, and even at some dollar stores. Be aware that cheap dollar store batteries are usually alkaline, not silver oxide, versions of the same size battery. Alkaline batteries may work perfectly well in many watches, but they have a somewhat different energy performance curve over time, and, in general, they won't last quite as long as a comparable silver oxide battery. In addition, for reasons I've never been able to figure out, some of the Fossil watches that I've serviced would not function with an alkaline battery--but would work fine when I put in a silver oxide battery of the same size and voltage. I have not been able to see a pattern to predict when this will and will not occur. Lithium batteries, whether "brand name" or generic, should have the same performance curve.

If you do open up your watch to change the battery and don't recognize the battery type/code on your battery, don't give up. Watch batteries have different numbering schemes, depending on the manufacturer. Here's a link to a cross-reference chart that will help you "translate" one code into another. I would suggest starting by looking at the #377 line to see if one of those cross-reference codes matches what you have. However, you may need to look around the chart to get an exact match:

http://www.watchbatteries.com/custom.aspx,,id,,75

As a final thought, the backs of some Fossil watches are very snugly fitted to their cases. You can generally get them off without too much of a problem, but there's a good chance you may need a jeweler's press to get them to snap back on properly. I've noticed this most with round watch backs; I generally haven't needed a press to close oblong or tonneau-shaped Fossil watches (or some round watches, too). A jeweler's press spreads the pressure evenly around the edges of the watch back and watch case, preventing damaging pressure on the watch crystal, watch movement, and watch back. Clamping the watch in a regular vise to try to press on the back runs a high risk of damaging your watch, and I do not recommend trying that, no matter how frustrated you get. It's much safer (and cheaper, overall) to tip someone with a vise a couple of dollars to close up your watch for you.

The vast majority of Fossil analog wristwatches take either a #377 or #379 watch battery. The #379, being slightly smaller, is somewhat more commonly found in women's watches than in men's watches, but I have seen both types used in men's and women's watches alike.
These batteries are commonly found at many drug stores, jewelry store counters at places like Walmart and Target, and even at some dollar stores. Be aware that cheap dollar store batteries are usually alkaline, not silver oxide, versions of the same size battery. Alkaline batteries may work perfectly well in many watches, but they have a somewhat different energy performance curve over time, and, in general, they won't last quite as long as a comparable silver oxide battery. In addition, for reasons I've never been able to figure out, some of the Fossil watches that I've serviced would not function with an alkaline battery--but would work fine when I put in a silver oxide battery of the same size and voltage. I have not been able to see a pattern to predict when this will and will not occur.
As a final thought, the backs of some Fossil watches are very snugly fitted to their cases. You can generally get them off without too much of a problem, but there's a good chance you may need a jeweler's press to get them to snap back on properly. I've noticed this most with round watch backs; I generally haven't needed a press to close oblong or tonneau-shaped Fossil watches (or some round watches, too). A jeweler's press spreads the pressure evenly around the edges of the watch back and watch case, preventing damaging pressure on the watch crystal, watch movement, and watch back. Clamping the watch in a regular vise to try to press on the back runs a high risk of damaging your watch, and I do not recommend trying that, no matter how frustrated you get. It's much safer (and cheaper, overall) to tip someone with a vise a couple of dollars to close up your watch for you.

It most likely needs a new battery - they don't usually last more than 2 years. For about $8 any watch or jewelry shop can change it. Sears also does it in their stores.

You can only go back to the supplier and explain the situation. At the price of these watches you should expect to get some product support long after the warranty runs out.

(can't help wondering why such a short warranty is offered on a mechanism that you can reasonably expect to work for many years.)

When you buy your watch the manufacture puts in a battery that is made to last 5 years so that the watch can sit on the shelf and not need the battery changed before you have even bought it. Batteries you buy from a store or a watchrepair usually last about 1.5 years. Sometimes you can find a watchmaker who carries the five year batteries, but most people don't want to pay the $25-$30 to have it installed so most places won't carry them for rear they will never sell.I would also tell you NOT to buy your batteries from a grocery store or a Wallgreens type place because those batteries could have been sitting there for months, or even over a year. If you go to a watch repair they go through so many batteries that almost evey time you are getting a fresh battery.