X40 Battery Maximization

[ErikD]

I want to have the smallest and lightest ThinkPad for daily use. I am always running around NYC on the subway for work, and carrying my laptop with me. So I went from a T40 to an X30, and now to an X40. So I now (just this week) have an X40 with brand new (direct from Lenovo) 4-cell battery. What I want is help on any ways to maximize my battery life (I am never away from a charger long enough to justify the extra weight of the 8-cell).

I am already using the IBM Power Management software set to maximum battery life. Would tweaking with NHC help much more? Anything else I could do to get the longest time out of a single charge doing normal work (Office and wireless internet)?

Thanks,

[sugo]

I have T42, which uses similar cpu and chipset as X40. The following helped to get my thinkpad to 4 hour mark on a full charge:

- keep cpu at 600MHz on battery
- undervolt cpu to 0.7v @ 600MHz
- enable spin-down of hard drive after 30 seconds
- use tpfancontrol to keep the fan off with reasonable temperature range. The fan consumes power too.
- disable any port or components that you don't use in device manager

[mfbernstein]

Unused devices (USB, PCMCIA slot, ...) can often be disabled in the BIOS (instead of the device manager) to save power.