I believe it’s impossible the battery to be the main cause of the problem. I think it’s the result of something.
From what you say the battery goes flat with no reason and all the problems appear after that. I think his losing power somewhere.
Sometimes you can turn your 147 with no problem, right? And I believe the problems star after, for example, turn the lights on, the a.c. right? Well, it certainly is the battery going flat. It loses the partial km’s memory too, right? Right.
One thing that you say that might be the cause: “When I switch off the engine everything turns off except the radio”. It should go off. That might be where the power is draining. You could turn it off but he might continue to lose power somewhere.
At your Alfa service they should measure the energy over some important connections (that spend more energy) sections.
(2011) Alfa Romeo Giulietta 1.6JTDm, Pack Sport 17", Pack Comfort
(2009) Alfa Romeo 159 1.9JTDm 16V QV, 170hp+360nm, Bilstein B4+TI springs, ConnectNav G2, Autodelta Air filter, Brembo Disks, Satin Mirror Caps
(2002/2009) Alfa Romeo 147, 1.6TS QV, Autodelta Remap, Autodelta Air filter, Eibach Pro System Kit
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