Dead battery is worth about $7-10 as a core here.

You can also get desulphators as stand-alone units on eBay for the $20 range, one of which is made in the USA. I mention this as I am skeptical of conventional chargers that advertise they "condition" worn batteries. I know Porsche supplies CTEK to customers so perhaps they do have the required magic.

You must use a desulphator with a charger, however. Some of the vendors neglect to mention that.

I have had some success with the stand-alone desulphators, a USA-made one (which I accidentally broke) and one that came from the UK, of all places. Only the UK one explained the need to use a charger... use of the desulphator alone on a really weak battery will kill it off for good.

Using the desulphators, I resurrected two very old diesel batteries that came in cars I purchased that had sat for extended periods. One was a Bosch, the other a Varda (sp?). While neither recovered enough to use year-round (too weak for winter conditions), both went from near zero on load tests to a high "weak" load rating... enough for starting on mild days.

In both cases my pricey "reconditioning" battery charger declared the batteries dead, shut itself off and said good night and good luck....

Just FYI.

Hey you!

I might just have to start a minority action group!