I have an Accumate - made by Optimate but also has a 6v setting (needed it for my MZs). I've also had it for years, certainly over 15.

I'm sure I remember reading somewhere that the Accumate had better battery recovery ability, probably because at the time it had improved circuitry compared to the original Optimate. That gem of information is most likely now out of date.

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Simon

Brighton, UK