I'd had this auto DAV on charger for a couple of days (takes a day to realise that one isn't charging) without the charger turning green, so figured it was dead, which didn't impress me. On closer inspection today, I could see there was quite a bit of gunk around the post etc, so took to it with cleaning products: vodka, dental floss type brush, alcohol swabs, toothpicks & all sorts.
I have never seen so much disgusting black stuff come out of a battery post cavity before! Gross!.
I admit I hate housework of any type, so battery maintenance is never high on my list of priorities, but even so, this was awful.
I have been using smileos since my larger auto DAVs arrived, around mid April, and can't quite work out why the batteries have taken such a gunking. Just another of my natural talents, I guess
Anyway, put the de-gunked battery back on charger, now reading green light. Am hoping this battery will have many months more of happy vaping.