Weak battery?

Over the past couple weeks, our car (1998 Hyundai Accent) has been left outside through a couple rather cool nights (0-5 Celcius). This is contrary to being parked in our apartment building's heated (~20C) underground lot as is the norm.

The past few starts haven't been as strong as usual. Yesterday, as my wife turned the key to return home from shopping, the car wouldn't start at all.
Dash lights, clock, radio and headlights all ran fine, however. When the ignition was turned on, the starter engages and then just pulls itself down to a stop--taking power to the dash lights, etc. with it.

She called for a boost, got the car started, drove home, and left it idling for about 20 minutes to bring up the battery charge. A couple hours later, I tried to start the car myself and it did start--No doubt thanks to the idle time earlier. (Thus I'm pretty sure the alternator can be ruled out.)

This morning, I tried to start the car again without success. Same symptoms that the wife experience yesterday.

Given that the starter tries to turn the engine over, that there is enough power to run accessories, and that a boost will start the car, I'm left to conclude that the battery is due for replacement. (Or so similar experiences in my days of radio control modelling have taught me: Battery packs can lose their ability to hold a peak charge with age.)

Are there any quick tests I can do to confirm, or rule out, the weak battery theory? I presume with a volt-meter across the battery leads, that the voltage drop between "at rest" and with the starter engaged readings should provide some information.

I haven't ruled out a loose connection somewhere either. Are there any trouble spots I should take a look at besides the obvious, being the battery leads?

Approximately 10/21/03 08:19, V. Grovestine uttered for posterity:
load on a battery is probably the 20-30 amps max for the heater blower so there is a bit of a disconnect in power requirements.

Worse, many batteries are constructed such that they fail very very ungracefully. Work fine right up until they give a bit of trouble, then bang, can't even light a weak bulb any more.

One thing to make sure of is that you have a 5W30 or 10W30 type engine oil, as the oil gets surpringly thick at cold temps and makes the battery's job more difficult. However, symptoms of wrong oil are usually that the engine will fire, but immediately die.

Yup. If the battery is more than a couple years old, just swap it.
Most battery sales places can make a better check that involves actually putting a load on the battery to avoid a skin charge looking like a good battery when it ain't.

Make sure they are clean and very very very tight.

The other places would be at the starter itself and also the main ground from the battery to the body as well as from the starter to the body. These all need to be extremely clean and tight to be able to carry starting current.

it doesn't sound like a loose connection. do Hyundais ever get those?
i'm starting to think they're the most reliable car on the road.

the battery's 5 years old and you're in a part of the world that's heading towards winter. a battery that's starting to fail will become obvious in cold weather.
i'd be 99% sure that replacing the battery will be warranted so you could either just buy one from the cheapest place or get an auto electrician to check it and then replace it at a higher price.

For the latest weather where i am click http://members.iinet.net.au/~farmerjim/

Average life of a new car battery is 3 - 5 years. If you are on the
5th year, you are running on empty. IMHO