Those steps came from here, xda devs.
1. Run the device down until it turns itself off.
2. Turn it back on and wait for it to turn itself off again.
3. Remove the battery for 10 seconds.
4. Replace the battery, but leave the device off.
5. Charge the device until full and then for another hour.
6 **Root users only** Using a Terminal Emulator, type “su” enter, followed by “rm /data/system/batterystats.bin”
7. Run the device’s battery down until it turns itself off.
8 .Turn the device on and charge for at least 8 hours.
9. Unplug the device, turn off, then charge for another hour.
10. Unplug the device, turn on, wait 2 minutes.
11.Turn off again and charge for another hour.
12. Restart and use as normal.
Quite a performance! Does it preserve battery lifespan, or is it more to do with slowing down battery drain and does it really work?
He mentions 2 interesting things:
"Generally charge them before they get lower than 50%". I didn't know that, so it's actually better to charge more often and not let it drain down?
"USB charging is actually better for the battery and you may get up to 1 hours more standby time." So you gain an hour standby but it takes twice as long to charge the phone.