Ok, I went to start my car this morning and it would not start. It didn’t even make a sound when I turned the key. In addition, the power locks don’t work. Now, I have not started my car for a couple of months (I realize this was stupid). I was wondering what the problem might be. Is it the battery, or something else?
That sure sounds like the battery to me. Try a few other electric devices, like the interior lights and radio, if they don’t work, you have no power coming from the battery.
First step is to go under the hood and check the terminals, make sure they’re clean and tight. If there’s a loose connection, tighten it and try again.
If it’s still dead, buy ($30-40 bucks for a basic unit) or borrow a battery charger and let it charge up the battery a good long time (read the manual) before trying to get the car going. A jump start will get the car running, but your alternator is not designed to charge a totally dead battery, it’s not a great idea to ask it to.
Sounds like a flat battery, almost definitely. (Did you leave an internal light on, perchance? Alternatively it could just have gone flat through not using it for a while, if the battery was on its last legs.)
I’ve had the same thing happening after leaving an internal light on for about three days. Get a jump start, drive around for a bit to recharge the battery, and you should be good to go.
Or not, if what Cheesesteak says is true. It worked for me, though.
Before trying to jump the battery, you might also want to check for corrosion on the battery terminals and make sure there is a good connection there.
You may want to top off the tank with fresh gasoline and throw some gas stabilizer in the tank too, especially if it is going to be a few months before you drive it again.
Assuming it is a dead battery, and assuming you live in an area that will have tempratures below freezing soon, you’ll want to do this soon. My understanding is that when a battery is dead, the electrolytes inside can freeze and warp the plates. If they warp enough they’ll touch and cause shorts which’ll ruin the battery.
For a onetime recharge, I’d say it’s not a problem, as long as you have a nice long drive at speed & low electrical load for a while.
I’d not want to do it regularly, as it’s not particularly good for either the engine, the alternator, nor the battery.
I predict a new battery in your future… (though that’s valid for darn near everyone 
)
A totally discharged battery may well be far less able to store a charge than it was new. It might hold enough to start immediately and then leave you stranded with no charge shortly afterwards. I recommend having it checked, and probably replaced, especially with winter almost here.
A trickle charge weekly is a really good idea for an out of use vehicle being stored out of doors. The equipment is generally less than twenty dollars if you shop around, and the lifetime of a single battery can be doubled by it. It will be more expensive if you need a twenty five foot outdoor extension cord to reach. Starting up and running the gas to charge the battery will be more expensive over time.
Tris
::: Sigh:::
Alternators are not battery chargers. Modern alternators are trickle chargers under most conditions.
Driving your car for 20 minutes will not fully charge the battery. It this case it probably won’t even come close.
Getting back to the OP:
Yes leaving your car for a couple of months can flatten the battery due to parasitic draw of the computers, clock, the radio station memory, alarm and other stuff.
If you want to try and save this battey get a small charger (< 5Amps) hook it up and charge the battery for a day or two.
Rule of thumb when charging a battery, if you discharged it slowly, recharge it slowly. If you discharged it fast, you can recharge it fast. A couple of months qualifies as slow.
Thanks for all the replies. Where would I get this battery charger?
Any automotive store, most home hardware stores… there’s a tool shop I frequent that has them.
Singular of data: I leave the office fairly late (to make up for all the SDMB ;)), and last year managed to have left my lights on all day on the coldest, most snowy day of the year when AMA is busy jumping batteries and dragging cars out of ditches and there’s no-one around to mooch from. After I finally got a jumpstart, the 30 minutes home + another 30 of idling had the battery working, and it’s been fine ever since.
Auto parts store, Walmart, Target, hardware store etc.