why my p990 battery is goin flat so soon

That does rather depend on how long your calls are?

However -- you should have left your phone on charge for about 8 hours or so before the first use. Presumably you (like everyone else) didn't.
You could try lettting it run flat then charge with the phone off for a good 8 hours or so before switching it on. You may need to do this a couple of times to prime the battery.

Also worth turning off any function you do not use -- WLAN, Bluetooth etc.
And the SE phones boost the antenna power if they get a bad signal, so you would suffer if you hang out in bad reception areas.

Or you could just have a duff battery.

It has been noted elsewere on this site that the battery in the P990 gets used up quite quickly, but we are talking a couple of days life, not hours.

I have an idea for you Steed, though I could be wrong...

If you use an exchange server to push your emails, the phone has to maintain contact with it's data stream - effectively staying on all the time. If I'm right and you use the server, it could be draining your battery perhaps...

Good luck with it -
Larry Z.
😊

Most phones have a talk time or around 3 hours... With 20 calls that only 9 minutes each before the battery is flat.

Plus if you use it for other things.

I found it lasts about 2 days ish.

I shouldn't even be reading this forum still, but thought I'd just mention that I had terrible battery life with mine until I switched 3G off. Having done that, the battery lasted ages.

turn of 3g,wireless LAN,GPRS,DIM the sceren brightness and you'll be better off.