Look for deals on the laptop battery. Pay attention to the maH ratting on the battery. A larger battery will be double. There are some advertisements to be wary of. At some places a longer warranty will cost more. You don't have to pay $120 for a battery.
You may want to keep the old one around just in case you need to use a rebuild service in case the battery becomes scarce. Rebuild services I've found generally to be more expensive. They can start by X-raying the pack, to know where to cut it open.
Ab external battery charger can sometimes be worth looking in to. They are invaluable when the DC power jck decides to bite the dust.
Chargers from
www.iGo.com are really nice. I don't like their website at all anymore, but I have used their products for a long time. Your charger will probably go south at some time. Some of iGo's chargers will work on planes, cars and automobiles. Only the Tip is changed. The "tip" programs the charger with the output voltage and current limits. Thus, when you buy a new laptop all that's required is a new tip. The tips may wiggle a little more than the OEM charger and this might be problematic. The charger's though are rock solid. They are also now flat and thin.
In general, this is true, but some manufacturer's are making the charger and the battery communicate with each other.
Cables from their early chargers where a bit stiff and would fail.
They also make adapters that can charge mobile devices as well. This generally is a separate add-on that piggy backs off of the DC output and creates the 5V or so needed for mobile devices.