Hello,

I am trying to get to the bottom of a problem I am having.

Battery keeps running flat, its only a few months old so took it back to where I bought it and they did a voltmeter test (?) that showed that the battery was good and that the alternator voltage was good but it had a 'ripple too big'. They told me it was an alternator issue but the alternator was replaced at the same time as the battery so I got a second opinion that said the same thing. I went to the garage that fitted the alternator and they have said it isn't the alternator at fault but the battery not holding its charge. However I have also been having various electrical issues e.g. alarm going off randomly that I have read can be due to a faulty alternator and I nearly always get an electrical hum / murmur when just starting or turning off the engine. I tried another battery and still have these electrical problems, and am thinking it is just a matter of time before it starts running flat. Could it be something else? Are there any tests I can ask for to identify the problem? Would an oscilliscope test determine one way or other if the fault was with the alternator? Should I get a parasitic draw test?

Any help would be appreciated, thanks