i've just had fun because of this , hardly used the car this past 2 months so it didn't get a decent run , came to start it and behold flat battery . so jump started the car and thought it was ok . oh no , because of this so called smart alternator it doesn't charge unless you have the lights, heaters, wipers etc on , as i am not a complete dummy , no really , i didn't have a clue about this bleedin smart alternator thing and thought , great a trip of 66 miles to get this sorted ! it was only by chance that i found out off a mate who had similar problems with his WR1 that there was nothing wrong with the car , all i had to do was drive around like a volvo for a while ie with the side lights on , and it would be ok ! 2 things i would like to know . what the hell is the point of this smart alternator ? and what a stupid idea in the first place , i was pretty annoyed that the garage didn't tell me about this kind of situation when i bought the car !! and yes i have had words with them

 

So what did you have to do? Drive around with the sidelights on to get the lternator to charge the battery?

 

yes that was what i had to do !!

 

Ok, wanted to know what the story was myslef,so i rang the bro who is a subaru mechanic. The reason you have to switch something electrical on to get the smart alternator to charge is so that an electrical drain is sensed. The ecu only allows a charge when a drain is sensed on the electrical system. Does that make sense?

 

Oh and the point of the smart alternator is that it reduces load.

 

Another point about Lead Acid batteries is that leaving one in a discharged state for any length of time will severly damage it.
Read here : -

http://www.progressivedyn.com/battery_basics.html

and then buy a new battery!

 

there are tons of threads on here with details of this issue, most of them relate to cars standing for much shorter periods of time. my 04 WRX was garaged & alarmed last week for 4 days. sunday morning subaru assist were called as it was dead. the guy who came out actually knew nowt about scoobs (thats another story) but his mate is a scooby nut so he called him on the mobi.
problem identified - smart **** alternator
solution (on my £20k+ motor) - drive around with your side lights on.
Now I know absolutely sweet FA about cars other than how to drive them and drain them of petrol so I took his word for it. After searching the site I found this coming up time and time again.
Other ideas Ive seen suggest upgrade to a 60A battery or have a booster pack on hand permanently !
I'm still at a loss as to how this seems to have slipped through design review after design review at subaru.
or am I missing something ?

 

Does anyone know how muc driving with the lights on you have to do to keep the battery charged as I don't seem to be doing much night driving at the moment. Or is the answer to just drive with the side lights on all the time?

 

i just drive around with the stereo on now and that seems to work fine , it's still a bloody daft idea though ! the annoying thing was that the dealer failed to inform me when i bought the car !