Battery/Alternator?

[Frodo]

Got a battery/alternator question. The battery in the Box is a few years old---I neglected to record WHEN I bought it (contrary to my usual practice), so I don't know exactly how old. Anyway, the car's been in storage since about December and has, for almost that entire period been on a Ctek battery maintainer. (My kid's got a battery out of his Celica in the garage that we'll switch the maintainer over to for a week or two from time to time. But it's been on the Boxster battery for at least 2-3 wks straight now.) The maintainer was indicating "Green", ie that the battery should be good to go, when I removed it to crank up the car for the first drive of spring---it's like 65 out and gorgeous

But when I went to start her all I got was the "click-click-click" one associates with a dead battery. After a few tries, I also started to get the idiot lights flashing and the window motors engaging for a brief fraction of a second whenever I'd try to turn her over. As I recall, that's the kind of symptoms I got several years ago when I needed a rebuild on the alternator. I get trunk lights, radio, etc, but when I tried the headlights I get nothin'.

Battery? If so, why would the Ctek indicate "Green"?

Alternator? A car should start with a bad alternator as long as the battery's okay, right?

Theories?

[mikehkang]

There may be something else not working, but between the battery and the alternator, your first guess has to be the battery. Yes, the car should start with a bad alternator. A bad battery, no.

This will tell you for sure. Amazon.com: INNOVA 3721 Battery and Charging System Monitor: Automotive

[TeamOxford]

Originally Posted by Frodo

I get trunk lights, radio, etc, but when I tried the headlights I get nothin'.

Most of your accessories are low draw, but the headlights take a lot of juice to power on. Battery is most suspect, not the alternator.

I believe there is a way to determine the age of the battery by interpreting some code on the unit, but I'm not absolutely sure about that. May be worth a quick Google search before getting a new battery.

TO

[JFP in PA]

Originally Posted by Frodo

Got a battery/alternator question. The battery in the Box is a few years old---I neglected to record WHEN I bought it (contrary to my usual practice), so I don't know exactly how old. Anyway, the car's been in storage since about December and has, for almost that entire period been on a Ctek battery maintainer. (My kid's got a battery out of his Celica in the garage that we'll switch the maintainer over to for a week or two from time to time. But it's been on the Boxster battery for at least 2-3 wks straight now.) The maintainer was indicating "Green", ie that the battery should be good to go, when I removed it to crank up the car for the first drive of spring---it's like 65 out and gorgeous

But when I went to start her all I got was the "click-click-click" one associates with a dead battery. After a few tries, I also started to get the idiot lights flashing and the window motors engaging for a brief fraction of a second whenever I'd try to turn her over. As I recall, that's the kind of symptoms I got several years ago when I needed a rebuild on the alternator. I get trunk lights, radio, etc, but when I tried the headlights I get nothin'.

Battery? If so, why would the Ctek indicate "Green"?

Alternator? A car should start with a bad alternator as long as the battery's okay, right?

Theories?

Contrary to popular beliefs, a battery on a maintainer can still die. The Ctek is holding it at the correct voltage, but the battery itself can no longer generate the amperage required, even though it has voltage.

Get the battery load tested; if it passes, check your cables for corrosion and resistance.

[Jager]

Inspect you battery cables, connectors, and terminations, on both ends of the cables (positive and negative). We have seen cables corroded and connectors holding-on by just a couple of copper strands.

[Frodo]

Originally Posted by JFP in PA

Contrary to popular beliefs, a battery on a maintainer can still die. The Ctek is holding it at the correct voltage, but the battery itself can no longer generate the amperage required, even though it has voltage.

Get the battery load tested; if it passes, check your cables for corrosion and resistance.

This I will do. (As in take the battery to AutoZone?)

I think I've lost my instructions to the Ctek. If, as you say, this is possibly a battery that died in spite of being on the maintainer, is it typical for the Ctek to indicate fully charged ("green")?

[JFP in PA]

Originally Posted by Frodo

This I will do. (As in take the battery to AutoZone?)

I think I've lost my instructions to the Ctek. If, as you say, this is possibly a battery that died in spite of being on the maintainer, is it typical for the Ctek to indicate fully charged ("green")?

Again, yes the Ctek (or any other maintainer) will show full voltage indication because the battery is at full voltage, but the battery's ability to generate amperage (which is what turns the engine over) is low. A maintainer has no way to measure reserve amperage in the battery, that requires a load test.

There is nothing wrong the the Ctek, but the battery is probably toast, unless your amperage problem is cable related.

[Jamesp]

Put the Celica battery in the Box to see if that starts it. If so, mystery solved. As always, be sure to get the polarity correct to avoid damaging the electrical system.

[Frodo]

Yeah, I thought of that too. Wanted to check with the kiddo as to when he planned on pulling the Celica out of hibernation and get his okay first...got it.

[Frodo]

Originally Posted by Jamesp

Put the Celica battery in the Box to see if that starts it. If so, mystery solved. As always, be sure to get the polarity correct to avoid damaging the electrical system.

That's what I did, and it cranked and started just fine. In fact, I've still got the battery in there (with the kid's permission) and have driven a few times, just to try it out. "It" being a smaller, lighter battery that he uses because the Celica is used primarily as a track car.

The kid tells me I should get one of the ones I'm using now (ie, get one just like the one I borrowed), but I'm fearful it'll let me down at some point. My question now: What do you guys and gals use, battery-wise? I'd be interested in opinions whether on full-sized or smaller/lighter units.

[thstone]

I use a small, lightweight battery in my Boxster race car where weight savings is critical. Otherwise I use a standard size battery (e.g., in the 996).

[Jamesp]

I usually get the biggest baddest battery that fits. I just bought one size too small, but that was what the battery guide said to get. Next time I'll do a little more investigation and get a bigger battery. The heat in Texas eats batteries so you need every advantage you can get.