Porsche Enthusiasts Club Forum

I didn't go down the route of using a PV cell in place of a condition charger because when on another site I was asking a question related to how long I could expect my BMW's battery to last parked up in an airport car park, as I needed it to last 30 days.

With no provision for a mains connection I was thinking that a PV cell would do the trick, but was advised against because of all the electronics that goes to sleep after a pre set time.

With the PV cell the open circuit voltage approaches 20 Volts and that would activate all the sleep circuits and consume more power so your PV cell would need to be large enough to cover that load plus some to maintain the battery in a state of charge. But I was only looking at a small output PV cell, 1.5watts which I had purchased previously.

It turned out that for the BMW with a good battery and fully charged it would last from 6 to 8 weeks (manufacturers data) After 30 days idle it started on the first turn as normal, unlike the 964 I had which would only last 2 weeks from experience, not sure how long the 997 would last

What about this one?
First google result when I searched for your one above.
http://www.accumate.co.uk/optimate%202%20leaflet.pdf

I haven't driven my 997 for a couple of weeks, and even then it was a very short trip to the nursery, not enough to charge the battery. The longer usual motorway drive was probably a week before that.

Well, now obviously the battery is flat!! First time it has happened to me (bought the car in Jan, and only done about 2 or 3k miles since).
I can hear the starter motor clicking, lights blink etc and all other electrics work fine.
Is it the battery?

If I get the Accumate or Carcoon if I find one, will this charge up and then solve my problem?
Many thanks.

I have found the Cetec units excellent, have used one for 7 years on my 993, battery always tip top, and the battery lives longer as well

Halfords sell the CTEK chargers up to £130!
http://www.halfords.com/webapp/wcs/stor ... yId_255205

Which model do you have?

Ctek 3.6 it is!!
http://911uk.com/viewtopic.php?p=787276#787276

I have the Multi XS 3600, I have used it for years, leave the car plugged in all the time I don't use it, on my car I plug it into the ciggy lighter

I also use one of those extension lead cassettes to run the power to the side of the car, and plug into that, great

I have read that some 993/996 etc will not work through the fag lighter, but for me it does.

Thanks Sam

Some of my cars have solar powered trickle chargers, some of them I have Carcoon battery conditioners connected.

The solar ones I have connected via the cigarette lighter, which we modify on cars without permanent live to it, only ignition live.

The mod is really simple, a good trickle charger or battery conditioner will be supplying less than one amp, so we splice in an extra wire behind the facias with a 5 amp fuse in it with the other end connected to a permanent live in the fuse box, the idea is that with the ignition on it will have a 30 amp fused supply, and with the ignition off it will have a 5amp fused supply.

The good thing about this, it means if the charger becomes a closed circuit due to a wire trapped or damaged, it will blow the 5 amp fuse and iscolate the battery from the charger, (with the chargers own fuse protecting it the other way), but with the ignition on, you can still use the cigar lighter or a phone charger. In an ideal world, your average satnav and car charger for a phone will not draw more than 5amps either, so if you forget to disconnect these before you switch off the ignition, you will still not blow the 5 amp fuse.

Seems to work well and protects everything.

The solar chargers do not push out many amps though, probably about .2 of an amp, I tend to use two of them, as it is not exactly sunshine city over here.. But on the average car, it should be drawing less than .2 of an amp anyway, especially once alarms have gone to sleep.

The Carcoon is amazing, I think they are the best conditioner out there, the thing I like is they periodically discharge the battery slightly and then recharge it to remove the surface charge which can fool some chargers into thinking the battery is fully charged. They also constantly monitor the battery. I have also known them to rejuvinate a bad battery that will not take a charge even from the workshop super massive battery charger on wheels.. Something to do with it de-sulphating the battery.. I only know it seems to do a good job.... They are also sold as the Dataman or something like that for motorcycles, same unit, different sticker.

Jon, the cetec units also do this , they are "smart" chargers, and are designed to monitor the battery condition, they also "find" that missing 5-10% which your basic charger or alternator wont, I am sure there are several very good conditioners out there but I have had very good service from mine

+1 for Cetec 3600, had one for years

Mine arrived today express delivery from Amazon, and it's on the car connected via cigarette lighter...

Good, I hope it is satisfactory

+1 on Ctek.

Got mine on Amazon for silly cheap.

Its an 8 stage.