Alternator or Battery?

[mike561]

I am probably going to have my battery tested at sears, but what im wondering, is how would i know if its really bad? when i jump it, the battery holds a charge, i shut the car off and it starts right back up, i did that a couple of times also. i was thinking if the battery is holding a jump, and it can start the car back up a few times as well, then it must not be getting a charge from the alternator.

[PeteA216]

If the altenator is going, then regardless of how long it sits before you try to start it again you will need to jump start it. If the battery is going after a jump start and after the car's ran for a little the batter should be able to crank the car back over immediately after shut off, however will have problems when it comes to starting after sitting for a little bit. But yeah, if you can get a free battery test, I say go for it!

[mike561]

yeah ill do that then

[1968 Pontiac]

Ancient chinese secret:

While the car is running, put the blade of a flat head steel screwdriver on the shaft at the back of the alternator; if it's magnetic the alternator is charging.

If the idiot light on your dash is glowing, the diode(s) in your alternator are fatigueing, which will cause your battery to drain.

Could also be a bad ground. I had that happen with my 91 Olds TS a few months ago. Intermittently the car wouldn't start, but it would always start with a boost. The it would go for weeks without trouble, but then sometimes it needed a boost for every start. Among other things, I thought it was loose battery connections, alternator, starter, wire grounding out somewhere, but in the end I replaced the ground from the battery, and that solved the problem. For many years now I've always inspected battery and electrical connections, and grounds, applied silicone dielectric, cleaned all contacts, etc. When I go the wreckers I also take the factory black and red battery terminal caps for all my cars. But this bad cable looked like the day it was made, on the outside at least, but it must have been corroded inside due poor maintenace at the battery at some point in it's life.

[mike561]

that sounds like a useful trick with the screwdriver

[randy78]

yes if it draws the screwdriver tip to it then its charging yep

just be careful and dont let it touch the alternator case or any other metal


if its charging then it will stick and youll know you have a bad connection between the alt and the battery, or a bad battery

have it tested at a local battery shop the smaller shops usually will do it free real quick, or auto zone

good luck

[bobss396]

I'm not sure if Sears will do a free test, they stopped doing that by me unless you have one of their batteries. But it should be cheap anyway.

How old is the battery? I tend to toss any that are over 4 years old. Clean up all your connections (or get new cables if they look funky) before a new battery is installed regardless of who does it.

Bob

[mike561]

yeah i cant really telly the age of the battery, i couldnt find a date sitcker or anything but it is a sears die hard. the cables look to have a little corrosion on the outside but still look solid.

[1968 Pontiac]

Most batteries are dead or close to it after around four years except Delco. I worked with a fellow that got 14 years out of one in a 79 Olds 98 that he bought brand new. The one in my 68 Pontiac that you see to the left is now ten years old. In the last two years I've driven the car for about three weeks total, don't disconnect the battery, and go in, turn the key and the car turns over no problem.

Delco batteries have the date code embossed on the top, but I can't remember how to decode them anymore. Maybe a forum reader can remind us all.

['97ventureowner]

Originally Posted by 1968 Pontiac

Most batteries are dead or close to it after around four years except Delco. I worked with a fellow that got 14 years out of one in a 79 Olds 98 that he bought brand new. The one in my 68 Pontiac that you see to the left is now ten years old. In the last two years I've driven the car for about three weeks total, don't disconnect the battery, and go in, turn the key and the car turns over no problem.

Delco batteries have the date code embossed on the top, but I can't remember how to decode them anymore. Maybe a forum reader can remind us all.

That's exactly what I was planning to say Most if not all of mine have made it past 8 years, and I've had friends and associate's Delcos go past a decade of service.That is the only battery I buy and install in my vehicles now.
The warranty date code is located on the top label of the battery. The first character is either a P or S. The next two digits determine the month, the third digit is year and the fourth digit indicates the manufacturing plant. For example, P 094N means the battery was made in September 2004 in the New Brunswick factory.

[bobss396]

Sears batteries have a code stamped into the case, plus a little round sticker sometimes. The code is simple, "B6" would be "February of 2006", hopefully not 1996. The code is hot stamped somewhere around the top perimeter of the battery in about 1/8" characters. Any Sears battery person can find it in a flash.

[PeteA216]

I'm gonna go back to praising Delco batteries. Here's a Comparason... My '89 GMC had the original A/C Delco battery until 2000 when a bad altenator resulted in a fully drained battery - 11 Years (probably could have went one more if the altenator didn't go. It then got a Sears Die Hard as a replacement that lasted until 2006 - 6 years. It now is back at the A/C Delco, so far so good. One more... My Caprice: Cheap K-Mart Champion battery installed in 2004, died winter of 2005 no longer hold a charge. It now has an A/C delco, and lasts the full nearly 2 hours at the drive-in even with the 2400 watt sound system. Again, so far so good.