hi well i got my 87 iroc 305tpi back from the shop several months ago and iv noticed every once and a while the car is hard to start and if i have the radio on for a couple mins the battery will die and i have to keep using my neighbors charger and now its under 30F outside and the car wont start and everything is tight and it just wont crank so my question is will i need to buy a new battery or should i just buy a motortrend batterycharger for now? i just start it so the car wont sit again and it's not drivn right now and by the way the battery is over 5years old and if i need a new battery where should i buy 1 for cheap and what is a good strong battery that is still not to expensive or should i just buy a cheap battery for now tell i get more money and can start driving it when i turn 15. thx

Could be either a weak battery or a current draw that drains the battery while it sits. You'll need a voltmeter to check what the is voltage while it's running, when the car is started and before and after it sits. IIRC, it should be at 15v when running, should be around 12v before and drop slightly during cranking and at 11-12 when you return after it sits overnight.

What weight oil do you have in it now?

You can take out the battery and take it to Advance Auto or Autozone or another large chain store and they can test it for free. Generally I've found that the WalMart batteries are as good as any other regular battery line and usually cost less.

Keep in mind that a dead battery can ruin the alternator, AND a bad alternator can ruin a battery. So you might need to have the alternator checked as well (also free test at most large parts chain stores), but you have to take the alternator out of the car as well.

Well although normally ide say its probably the battery (although ide make other tests first and load test it to be sure) and it should be replaced, how long till you turn 15? Thing is if thats not for a year or 2 why buy a new battery when batteries only typically last like they claim 3-5 years? And thats not so much from use batteries have a shelf life so why waist part of the life span of a new battery if the cars not really driven just started from time to time? The other thing is it could be a short draining the battery. This can easily be tested for by measuring the current draw when the cars off. Lastly the charging system a quick test is to measure the battery voltage with the car off it should be 12V then start the car and re measure the battery voltage the voltage should now be 14V if it is your charging system is working if not then dig deeper into the charging system issue. Last word of advice should it be the battery is the issue and you want to replace it there is deffinetly a stark difference in quality when it comes to batteries. For example i despise NAPAs line of batteries from the very bottom of my heart. Ive had terrable luck with them and even the people who work there have told me they were crap. However that was a while ago and they may have gotten better since then so dont just take my word on it. So i guess what im trying to say is dont get the cheepest battery you can find as it will cost you more in the long run with all the premature replacements, dont spend billions of dollars on a battery because although even if they were better quality cheaper ones wil do the job just as well and both are limited but the shelf life of batteries of that type of construction. Now although i wont recommend a specific brand of battery the best way to find if a particular brand battery is of quality is to do a google search and check up on a particular brands reputation.

I have had good luck with Napa batteries. Or, get a Les Schwab battery if you can. They have awesome customer service.