You will have voltage surges etc with bad batteries plus your meter probably isn't calibrated?
If you have any fear fit one of these little jobbies
http://www.ebay.co.uk/itm/200627678428?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
If you have any fear fit one of these little jobbies
http://www.ebay.co.uk/itm/200627678428?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
