Porsche Enthusiasts Club Forum

I have only owned my 944 since October 2011. I don't think the battery was great even then, as with a week or 2 of non-use, it would barely start.

So I bought one of these for the winter months:

http://www.amazon.co.uk/Visua-Powered-C ... B005BDRO5A

I was assured by other buyers that it would actually charge my battery. I've given the solar charger a hard time by starting with a completely flat battery. I've had the solar charger plugged in for a month now. It hasn't made any noticeable difference.

Am I fighting a losing battle - will it ever charge from solar?
Is my battery permanently dead after being completely flat for so long?

Solar chargers - dead loss, in my opinion (especially with a flat battery to start with)

Firstly - get your battery checked out professionally.
Secondly - replace the battery if found to be faulty.
Thirdly - check for any excessive battery drain.
Fourthly - get yourself an "intelligent" maintenance type charger.

Hope this helps......

Bob

Lots of Posts recently on Batteries!
viewtopic.php?f=25&t=12306
It's that time of year for suspect batteries, they don't like the cold.
Why not do a Google search on "Free Battery check" and get it checked out (eg Kwik-fit!) that way you will know if its NBG
(as Bob says)
Would recommend Bosch Silver S4-008 and then get a proper charger/conditioner eg Carcoon. had one for 7 years and wouldn't be without it now.
HTH
Clive

I thought it was going to be so easy, plug in the solar and forget!

I can borrow a decent mains charger. I'll see if it takes / holds a charge.

You're right Clive, they all go wrong at this time of year. I read the other post as well.

The cheapy low power solar charger I have for the 944 works OK & nearly covers the stereo/alarm drain. It extends the won't start flat battery mode from around a fortnight to 4 weeks on mine. A 7W one like this is nearly 500ma & should certainly seriously help.
However especially at this time of year the battery needs a once every 6-8 weeks boost from a battery conditioner type charger.Especially if it isn't being driven regularly. I suspect your battery was creamed anyway, this will have just helped it along!

Thanks Jim. That's exactly what I was hoping to hear!

So I charged the battery, and did a capacity test:

It ran a 55W headlamp bulb for 7 hours. That's 32 Ah by these calculations:

55W / 12V = 4.58333 amps
7 hours x 4.58333 = 32.08333

The battery is supposed to be 43 Ah. How worn out is it?
I'll see if I can keep on top of the car's drain with my solar panel.

Next tests: Measure the current draw of the car when everything is "off".