Faulty electrics

Advice please:

My battery went flat during the week. Sounded a bit sluggish starting in the morning, even more sluggish starting to go home, then dead next time I tried it. I’ve had it on the Optimate and it says it’s “weak”. A bit of a surprise at only 18 months old and bike used most days.

Do I accept that the battery is at fault and get a new one or does it suggest a fault in the charging system? How do I go about checking that using a multimeter and a complete lack of technical competence!


Best way to check the charging system is to put a multimeter across the battery terminals with the scale set to 0-20v dc, and rev the bike to about 5000 RPM. You should see and reading of around 12.8 to 15.5 volts.

Have you got extra electrical “bits” on your bike that could be too much for the battery, or uprated headlight bulbs etc etc??