I just discovered this fantastic piece of software from rightmark that allowed my battery to last longer per charge and also let the netbook run far cooler.
Let me show you what I did to my 2-in-1 dell netbook model 3147.
Step 1: Rightmark Processor Power Management (PPM) Panel.
This freeware software allows for the throttling and tweaking of CPU voltages. My netbook had the annoying habit of running at 100% CPU especially waking from sleep mode. This neat software package fixed that issue for me!
Step 2: Enabling Throttling.
As highlighted in the screenshot, that feature needs to be set to ON. By default it was off.
Step 3: Enable Idle.
This has to set to ENABLE IDLE. The default again was off.
Step 4: Optional: a Little More Speed in Power Saver Mode.
While sipping battery power, initially the software slowed down my netbook but not worryingly so. To speed it up a bit, the increase threshold needs to drop from its default value of 90% to something far lower. I choose 30% for a good compromise with power savings and responsiveness.
So that's it! This is how I made my netbook last far longer per charge!