Batteries have long been the bane of travellers, who often find themselves needing extra batteries for digital cameras, video cameras, mobile phones and the like when they're out in the field for prolonged periods.
In some cases, the burden of the spare battery has become lighter thanks to larger-capacity batteries in digital SLR cameras, which last much longer than those in smaller devices. Yet if you're going to be using your device for most of the day, you'll probably need a spare battery.
Consider investing in a spare battery pack that charges from AC power and can be taken on the road and plugged into a whole range of devices using a universal plug set.
Make sure you get them before you head out into the field, as rechargeable batteries usually have a proprietary design that makes them extremely difficult to track down when you need them. If you can't stomach the three-digit prices manufacturers usually charge for these special-order items, search for the words 'battery' and the model number of your equipment, and you're likely to find a suitable replacement for much less cost; we recently tracked down a high-capacity video camera battery, quoted at nearly AU$200 by the manufacturer, for AU$35 on eBay.
If you're buying new batteries for a trip, the usual rules apply: charge for 16 hours before your first usage and run it to empty on your first day of usage. From that point on, while you're travelling make sure you include battery charging into your nightly regime: charge your batteries, in or out of the devices, as soon as you get back from your excursions so you don't forget to take care of them later. Since most notebook PCs require the battery to be plugged into the notebook for charging, you'll have to be particularly diligent in swapping between charged and uncharged batteries so both are ready for use the next day.
Another option for charging is to get a separate universal Li-ion battery. This is a large battery pack that charges from AC power, then can be taken on the road and plugged into a whole range of devices using a universal plug set as though it were an AC power source. Such a battery pack is a worthwhile investment as a backup if you need to use a variety of devices in the field.