At least not in the way you might think. It's a common misconception amongst drivers that if their battery is flat, a good long drive will charge it up. After all the alternator generates power, right? Well yes, and no. Have you ever seen or driven a car where, as you sped up, the lights got brighter? That's because the battery was dead and all the electrical power was coming from the alternator. The faster the engine spins, the more power the alternator provides, and the brighter the headlights become.
In a properly functioning car, the 12V electrical system is mostly reliant on the battery itself. The alternator provides a 'topping off' charge to help maintain the battery, but can't really be relied on to charge it. Why? Because when your car is running, it consumes quite a bit of electrical power between all the onboard computers, wiring harnesses, instrumentation, headlights, radios, electric windows, high- and low-tension circuits etc.
The alternator in most cars is typically sized to match the demands of a running car. In other words, when the engine is on and the car is running, the alternator compensates for the electrical load and typically doesn't offer much more. Sure there might be some surplus power produced at speed, but to fully charge a nearly dead 12V battery would take a 2000 mile drive at 80mph or more with everything electrical turned off. A quick 10 minutes down the motorway isn't doing anything for you.
That's why you should invest in a battery charger if you ever find yourself with a low battery. Use the grid's power supply to charge your car's battery instead of trying to overload your alternator. Chargers come in many sizes from 0.75 to 1.5 amps for slow 'trickle' charging, all the way up to 200 amp quick chargers (although you'll need a dedicated electrical supply for something that beefy). Optimate, Battery Tender and Black & Decker all do reasonable chargers in the $20 to $60 range, available from most local car parts stores or online mega vendors, and using them is pretty easy.
They'll typically come with a variety of connectors - clamps, ring connectors and accessory plugs. The accessory plug might seem like the ideal choice but many modern cars don't have live 12v accessory sockets when the ignition is off, plus you're trying to charge a hefty car battery through tiny cables so I just wouldn't recommend that. Ring connectors are good if you need to charge the battery time and time again because you can wire one end of the charging cable permanently to the battery.
The most useful connectors are going to be the crocodile clips. Simple to use - connect the red one to the positive battery terminal and the black on to the somewhere on the chassis or engine, plug the charger in and leave it alone. A decent modern charger will be able to charge in three or four different modes - bulk charge, top-off and maintenance are the most common three. It should choose which mode to use based on the condition of the battery, and there'll be a light or indicator on the charger to tell you what's going on.
Two final points : some cars, notably high end Audis and VWs, have their 12v battery in the trunk or under the driver's seat. Typically they'll have charging posts under the hood somewhere for easy access - Audi put theirs under a plastic flap at the back of the engine bay, in the middle. Flip it open and there's a "+" post in there. For the negative terminal, just clamp the clip to any part of the chassis or engine where there's bare metal.
And secondly : if you have to keep charging the battery, it means either your alternator is about to give up, or more likely, the battery itself is about to give up. Expect 3 to 4 year's life out of a normal 12v car battery, irrespective of what the manufacturer or guarantee tells you. 5 years is out of the ordinary. 6 years is extreme. If you live anywhere with wild temperature swings, expect 2 to 3 years before you need a replacement.
