Didn't find anything here when I searched for "smart charge" - which surprised me given how it seems to be a pita to diagnose. When we picked up our 2008 C-Max last week the battery was flat and the garage just bunged a regular lead-acid battery in. Now I know it must be Siver-Calcium and that's what's fitted now. But I got to wondering why a battery that had only seen 11K miles was in such poor shape - the charging system maybe?
SO I set about it with my meter and sure enough only 13.5 to 13.7 Volts ever seemed to appear on the battery. Then I read-up on the smart charge system and realised that it didn't always put out the full charging voltage of 14.4 (like cars used to). Now I've never seen 14 or more - even when skimming the battery down to 11V with the lights on, engine off. After starting from such a depressed battery I would expect 14.4 or more (after the built in delay) but nope.
I have seen the PeterCooperRepairs
page which describes the system, but have stopped short of dropping the engine underside cover to probe the back of the alternator - this is what I think the garage ought to do - but they insist all is well.
One other oddity is that while I get 13.6V most of the time, if I put on the lights, heater fan and the heated screens, the alternator can't keep up and the battery volts drop to around 12. Not much use in the winter. Could someone else please try this
and report the battery voltage (easy if you know how to get the reading on the info display - only take a minute!) The alternator looks pretty puny so maybe this doesn't indicate a fault. TIA.