DEAD Battery Question......

[NardisCNC]

Yesterday I got in the Midget, turned the key on and the battery was 100% dead. Wouldn't even power the elec fuel pump which is the first thing I always listen for. It's a Duralast Gold battery with the 3yr free replacement from Auto Zone, that I've only had about 2 1/2 years, so getting a free replacement is no problem. And they did check it indeed confirming it was dead, not charging.

My concern is this.... Can batteries just randomly go bad like this, or was it a short that killed it? How can I check for a short? What should be the resistance between the battery terminals (unhooked) with the key off? Thanks for any answers! - Nardis

 

[britishcarkid]

Make sure all of your electronics are off, radio lights, ect.

 

[JodyFKerr]

I've had 6 Autozone batteries just completely die in the past couple years. Admittedly, Arizona heat is really hard on them, but they just don't seem to last like they used to. Note, the 6 were spread across multiple cars, not just one.

Jody

 

[bug_sixty]

Just one cell goes and it's toast. one minute its good the next its not!

 

[JOeyKnapp]

To test for a current draw is easy if you have a DVM. With a working battery in the car and everything off, unhook the positive (or negative) battery lead. Have the leads on your DVM plugged in to the amperage spots. Put one lead on the now free battery terminal, and the other lead on the other end of the battery cable you removed. Set the meter to Amperage and you should see what your residual current draw is. On a car like this I would think it would be almost nothing. If you do have a short somewhere, there will be a draw in current and that will show up on the meter. To start trying to narrow it down (and this is easier on cars with more fuses), start removing fuses to disable the circuits in the car. If you see a drop in the meter after removing a certain fuse, you know that is a spot to start checking in.

 

[Sarastro]

If your battery is totally dead, not even powering things that have a small current drain, and can't be charged, something probably became disconnected inside. It happens.

If it were just dead from a continuous current drain when it was supposedly off, it should be possible to charge it. Sometimes it can be tricky to get a totally dead battery to take a charge; you might have to use an external charger, but still it should be possible.

Even so, it's a good idea to check for current drain, as described in the previous post, to be sure that when everything electrical should be off, it really is off.

 

[NardisCNC]

Thanks!! I will test for a current draw! Don't know why I didn't think of this in the first place. I did check my lights which are the only thing that could possibly be on with the car off. Hopefully it's just a bad battery. In general, who makes the best or most reliable battery? I always buy whatever has the longest warranty from whoever, usually auto zone.

 

[Scott_Hower]

Thanks!! I will test for a current draw! Don't know why I didn't think of this in the first place. I did check my lights which are the only thing that could possibly be on with the car off. Hopefully it's just a bad battery. In general, who makes the best or most reliable battery? I always buy whatever has the longest warranty from whoever, usually auto zone.

A bunch of us are using the WestCo battery that Moss sells as a replacement for the Miata; if can be found at several sources. It's small, but most importantly, it's an AGM type (the electrolyte is absorbed in figerglass mat). Mine's coming up on 6 years now and still works great. It does not discharge if left for long periods of time. I got tired of buying a new battery every two to three years.

Two things kill the cells in batteries: heat and inactivity.

 

[Sarastro]

I know that better batteries exist, but in all honesty, I think your approach of just getting something locally with a good warranty makes a lot of sense. It's simple and cheap, and if the battery dies early, you just get a new one under warranty.

These cars don't require huge cranking currents and usually aren't used much in the winter, if at all, so those demands on the battery are minimal. The primitive electrical systems don't do a good job of keeping them charged optimally, so the battery's lifetime is likely to be short compared to use in a modern car. So, make life easy for yourself...!

 

[reddsprite]

My Sprite is used sparingly and I use a optima red top group 34 battery. Because of the location I do not use wet cell batteries anymore.What I do use is a relatively inexpensive battery maintainer that keeps it in good shape and always charged for club outings and hair of the moment top down excursions. I use the same battery maintainers on my motorcycle batteries as well. These are great garage tools when you live in a wet climate and dont use the cars/motorcycles much in winter.

 

[mightymidget]

not to bash the big box car parts stores but I have heard rumors that there batteries ( like wal-marts shot gun shells) aren't up to snuff. I got tired of failures and presently buy my auto parts from NAPA or dealer. I have found some internet sites that make buying dealer parts reasonable.

 

[Sarastro]

I also use NAPA for all the batteries for my modern cars, and for the last one I put into the Sprite before selling it. Always had good luck with them.

My Porsche has an Optima, and it seems like a good battery--should be, for what they cost. There, it's really important, as those cars rust awfully easily.

 

[Scott_Hower]

These cars don't require huge cranking currents and usually aren't used much in the winter, if at all, so those demands on the battery are minimal. The primitive electrical systems don't do a good job of keeping them charged optimally, so the battery's lifetime is likely to be short compared to use in a modern car. So, make life easy for yourself...!

I suspect winter inactivity is likely what's killing his batteries. I've never had an issue with a properly maintained LBC charging system (clean, tight connections, etc).