AO Silver Member
Join Date: Mar 2003
Possibly. But did they just do a test with nothing on? A dud battery will show enough voltage straight after a run but what does it show the next morning. A fully charged battery should read about 12.6 volts. If the battery reads 12.4 volts or less, it is low (discharged) and needs to be recharged.
After charging the battery wait a few hours (to allow it to settle), connect the voltmeter to the battery then start it. A charging system that is operating normally should produce about 13.5 to 14.5 or more volts at idle. If the charging voltage is less than 13.5 volts, the alternator is not putting out enough current to keep the battery charged.
For a new battery you should also check the dealer. The OEM unit (with a higher cold cranking capacity) will cost you about £120 and fit as designed.