Connected an old Optimate charger to the bike battery today. The two lights on it lit up, suggesting that (a) it is connected and (b) the voltage across the terminals is 12.8V or greater.

When I put a multimeter across the battery on its own, I got a reading of 13.6V – but yet when I connect the Optimate, I get exactly the same 13.6V reading :wassat:

I’d have thought the voltage would be higher – somewhere up round the 14V mark, similar to the bike’s own charging system. Wondering now if it’s working at all. Is there anything you could measure in terms of current or voltage to see if the charger is working the way it should ?