Which HP530 do you have: The Celeron version, the older Core Duo version or the newer Core 2 Duo T5200 version? I had the older Core Duo version: battery lasted me at LEAST 1.5 - 2 hours. With minimal usage, I got close to 3 hours. Friend of mine has the newer HP 530 with Core 2 Duo T5200: He gets only slightly less (1 - 1.5hours with heavy usage).
1) Does your battery charge to maximum?
2) How long does your battery take to charge?
3) Do you often let your battery go flat?
4) If you let your battery go flat (to the point where it turns itself off), can you turn it back on again after that (without charging first) ?
1) The battery may not be charging to maximum, which could be because of a hardware fault or because you need to recalibrate your battery.
2) My battery took approximately 2 hours to charge (with the notebook on and being used).
3) Letting a lithium ion battery go completely flat is a bad thing. You should avoid it as much as possible.
4) If you can turn it back on again after it dies from a flat battery, then it's more proof that you need to recalibrate your battery. My HP 530, once it turned off from a flat battery, would NOT turn back on again until it saw some charge. This is also a dangerous thing: if the battery REALLY IS empty, then running the notebook will take the lithium ion battery below its "safe" operating region. BOOM!
To recalibrate your battery:
1) Do a full charge (notebook off).
2) Use notebook until battery dies completely. You may need to change some settings for this to happen, as Windows will turn the notebook off before battery is completely empty (or at least go to hibernate). I know I said letting your battery run dry is a bad thing to do, but in truth, it's not too bad if it happens once in a while.
3) Do a full charge.
4) Some say you should repeat this procedure a few times to properly calibrate the battery.
5) This recalibration should occur every few months (depending how obsessive you are).
More tips to improving battery life:
1) If you don't often use the battery, consider removing it when it is at 75% charge, and storing it somewhere cool and dry (batteries have a limited number of cycles in them).
2) Consider getting a longer-life battery.
3) Consider tweaking your operating system's settings (or better yet, switch to a better operating system).
4) Make use of the screen-dimming capabilities.
5) Turn wireless off when you are not using it.
But at the end of the day, your mileage will vary.