hi i have a compaq presario v5000
it shuts down without warning and no blue screen
i dont think its an heat issue as im using a lapcool cooling pad

can anybody help

Cooling pads work great, I have one on mine.
But you still need to blow compressed air through the computer occasionally as the pad tends to blow dust into the PC.

This could be caused by a bad or dying internal battery...

hmm... I never knew that would shut the computer down, I only thought it would lose the memory (clock, etc.)

strategic,
not the CMOS battery... the 19 volt DC battery

What does the battery icon on the task bar tell you? What per cent is it charged to? Does the notebook work normally on AC power? If your battery is the problem you might try sending it to the folks at batteryrefill.com. They take old batteries and send you back a replacement. I've used them a few times and they claim their replacement batteries are "better" than some new ones. They are definitely a lot less expensive.

Examine the power socket carefully. Certain models of the Compaq laptop brands have had the socket break loose from the board. Very difficult and costly to fix unless you are good with a cold solder iron.
Also, feel all the way down the cable on the power adapter... feel for lumps or bulges... If the adapter has been stretched enough to break the wires a little bit... then any movement can cause the shut down.
New adapters for that model are as low as $11 on eBay.

I have recently worked on a computer with this issue and it was a loose DC jack. It was an HP laptop, and it was a VZ5000. If you have anything important on the computer, be very careful, I was lucky enough not to destoy anything, but after all was said and done, I was warned that the DC jack could have arced and destroyed the mobo. I obtained an XC1000 cable and the computer is now charging through that (plugged into expansion port, which I believe your computer should also have). Best investment ever.