I’ve got ‘66 Starfire with an internally regulated alternator which I believe is outputs 95 amps or so. The car gets regular use and is on one of 2 Schumacher battery charger/maintainers when stored.

This week my Schumacher SC1280 showed a SUL error when charging the Starfire battery. The manual said that error means the battery is sulfated, meaning crystals are forming on the lead plates which will eventually lead to battery failure. Over the past 3 days I let the charger/maintainer run its “desulfation” program which seems to be variably charging the battery over a 24 hour period to reduce or eliminate the crystals.

At the end of 3 days letting the charger do its desulfation charging thing, the SUL error was still there. Also, the charger was showing voltages all over the place as the desulfation program ran. I’m used to seeing the chargers just turn themselves off when the batteries are at 100%, not this SUL error.

I checked battery voltage and it was 12.81 across the +/- terminals, so it wasn’t bad __yet__. But since i have no way of knowing when it might go bad, I replaced it under warranty.

Am I worrying too much? Did I just junk a good battery?

Yours, chemically ignorant,
Chris

 

If you replaced it under warranty, why worry. It was most likely still good.

 

Thus far how do you know the Schumacher SC1280 isn't bad? I think I'd hook up another/different Battery Tender since from what I understand from what you wrote, the battery tender was displaying peculiar SUL errors while the battery read 12.81V.

 

Chris,

Your battery could have had a sulfation problem. Or, as Norm said, your charger could have had the problem.

I did a bit of research on battery chargers about 10 years ago and found that a Swedish electronics company (CTEK) had the most logical explanations of how their chargers work to keep many battery problems minimized.

I learned in a long scientific career about whom to trust when you don't have personal knowledge, and seeing logical explanations was a prime indicator of trustworthy information from trustworthy companies.

Another indicator was not having any statements that I knew to be false or illogical. CTEK passed that screen as well.

I've used their chargers since then, exclusively on AGM batteries. The only time I got sulfation errors was on a four-year-old calcium/lead AGM. It still started the car, so I persisted using it, knowing that AGMs don't leave you suddenly stranded, they communicate end-of-life. And within 6 months I got lower cranking speeds and replaced it with a pure-lead AGM.

I'm letting you know this, so you can make an informed decision. PM me your email address, and I'll send a CTEK document for your review.

Gary

 

x2

Might want to double check that charger.

 

X2 on CTEK. I don't trust Schumacher.

 

I checked the new battery today. Got the same error of SUL. Like all of you, I suspect a bad charger. You all got to where I got today. As my sister says, "Great minds think alike".

I think I'll take it back to my (very good Napa) parts store & check a few batteries in their shop if they'll let me. I'd like to survey a bunch of batteries to confirm that the test device is not trustworthy.

I'm happy to replace a bad tool. I have a thing about bad/crappy tools. In my middle/older age, I try to avoid them.

For mid-60's big olds, if the battery don't work, you ain't goin' nowhere. The corollary is - if the battery charger don't work, best to replace it.

Honestly, I just want to get back to stasis - once the battery is charged, the maintainer shuts down reading 100% until needed again.

Cheers
Chris

 

Just to close this out, the battery charger was indeed bad.

It surprised me because it was just few years old well rated Schumacher SC1280. I had upgraded to it over a much simpler one I took over to my non-driving Mom's house to keep her car road worthy..

I replaced it today with the Schumacher SC1308. It's heavier than the last unit and I my battery was fully charged after yesterday's all day thrash on the horn in my tilt & telescoping column.

Hope this one lasts longer that the previous one

Chris