How old is the battery? There is a date code impression stamped on the top of most batteries, and it usually begins with a letter and a number. A=January, B=February, etc…, the second position is the last digit of the year, 2010=0, 2011=1, etc… Most manufacturers use this code, although some will skip I for September and use J to keep from confusing an I with a 1. This is the date of manufacture, not when you purchased it. Most batteries are sold within 3 months of manufacture.
If you don’t know, how old is the car? How long have you owned it?
Batteries usually last 3 to 5 years. Yes, most autoparts stores will test your battery, but a good battery that isn’t fully charged will fail their test. If you are depending on your car’s alternator to charge your battery, well if the alternator is not working well, it will appear you have a bad battery.
For about $15 you can get a 1-2 amp battery charger at WalMart that has a maintainer circuit that will not overcharge your battery. IMHO, all car should come with one wired into the electronics of the car, so all you would have to do is plug it in. If you are going to own a car, you should have one. Charge it up overnight (mine has a LED that tells me if the charger is charging or if the battery is fully charged). Once you know it is fully charged, get it tested.
Alternatively, if you put it on a charger and get it fully charged, and the battery is over 3 years old and it gives you any more trouble, just get a new battery. Chances are, if it is giving you trouble, the battery is bad. If it is the alternator or voltage regulator or some other component, you won’t be able to find out unless you have a fully charged battery to check it out.
From your symptoms, it sounds like you had a discharged battery. It may be bad, or maybe not. Batteries are funny. I’ve had a bad battery that wouldn’t do anything, but if you jumped the car, it would work fine, start again just like nothing was wrong. Next day, maybe two, it would need a jump. Then, it would be like before. After a couple of these, I just replaced the battery. Good as new.
excavating (for a mind)