That drop is definitely borderline.
If it fired up fine I'd be slightly nervous about investing in a new battery just yet until checked for any other issues such as bad connections / rusty earthings etc.
If everything else looks ok though I'd go for a new battery, as the 'recommended' limit while cranking is 10v, so probably is the culprit.
Mine drops to 10v and loses power quick if I have side lights on etc while engine off, so I'll probably be doing the same sometime next year.
If it fired up fine I'd be slightly nervous about investing in a new battery just yet until checked for any other issues such as bad connections / rusty earthings etc.
If everything else looks ok though I'd go for a new battery, as the 'recommended' limit while cranking is 10v, so probably is the culprit.
Mine drops to 10v and loses power quick if I have side lights on etc while engine off, so I'll probably be doing the same sometime next year.