[fpena944]

My workhorse 996 is now taking it easy most of the time while the Cayman and Cayenne take on the daily driving duties.

Since I'm parking it sometimes for 2-3 weeks at a time, I have significant battery drain taking place.

I know the usual solution to this is to plug it into a trickle charger and problem solved. The issue with me however is that with a two car garage the 996 is the odd man out and sits outside.

So what can I do to keep the battery alive? I have a jump starter that I use but I imagine doing that a couple of times a month likely isn't very good for the battery. Does the car use less power if I don't turn the alarm on? What do other infrequent users of these cars do?

[Scott at Team Harco]

Trickle charger is your best insurance. I ran a jumper off the battery to the little trim access cover. The trim piece needs to be cutout slightly to allow routing the connector. Hides away when not in use.

[i am not a traitor]

My workhorse 996 is now taking it easy most of the time while the Cayman and Cayenne take on the daily driving duties.

Since I'm parking it sometimes for 2-3 weeks at a time, I have significant battery drain taking place.

I know the usual solution to this is to plug it into a trickle charger and problem solved. The issue with me however is that with a two car garage the 996 is the odd man out and sits outside.

So what can I do to keep the battery alive? I have a jump starter that I use but I imagine doing that a couple of times a month likely isn't very good for the battery. Does the car use less power if I don't turn the alarm on? What do other infrequent users of these cars do?

Park it in my driveway and I'll keep it charged for you.

[SeanR]

Start by pulling the relay box cover and feeling around for a warm relay. Temp gun may make it easier to locate what is pulling a draw. It may also be as simple as one of your illumination lights are staying on due to being switched on or a pin is broken and not cutting the power, such as the frunk light.

[worf]

Terminology is also important: You want a Battery Minder or Battery Tender not a “trickle charger.” The latter term is often used expansively to cover both types of devices. Also, if you have an AGM battery you will want a Minder/Tender specifically for AGM batteries.

This, if you get tired of looking for the drain.

And, yes, it is reasonable(*) to assume that you will have less parasitic draw with the alarm off.

Aftermarket stereo or other add-on gizmos? Notorious for excessive current draw.

In terms of reasonable, this is true for the 9[89][12] generations. Those also have a “transport mode” that can be switched on with PIWIS (perhaps iCarSoft and Durametric too) that drastically reduces current draw. 996? Dunno.

[Scott at Team Harco]

Good point on 'trickle' charger. I've ruined a few batteries (for car stereo audio in garage) using them. The electrolyte will boil off if you aren't paying attention. Tender/minder is the way to go.

[fpena944]

Trickle charger is your best insurance. I ran a jumper off the battery to the little trim access cover. The trim piece needs to be cutout slightly to allow routing the connector. Hides away when not in use.

That is a nice little setup. But just trying to figure out how to then route an electric cord to where my car sits without having people trip over it since it would have to cross a walkway.

Park it in my driveway and I'll keep it charged for you.

Haha I'm sure! I should drive it more often but as it is I barely drive anyway. I go to the gym and I drop my kid off at school. That's it, so at this rate it'll take decades for my Cayman to hit the same mileage milestone that my 996 has achieved.

Start by pulling the relay box cover and feeling around for a warm relay. Temp gun may make it easier to locate what is pulling a draw. It may also be as simple as one of your illumination lights are staying on due to being switched on or a pin is broken and not cutting the power, such as the frunk light.

I always thought this was just a common issue with the 996 series? I remember going to test drive a turbo once and seeing the dealer have a tender on it because he said it would kill the battery after a couple of weeks sitting. I just thought that was normal behavior. But I guess looking for parasitic draw would be a good idea if this isn't the way it's supposed to be.

Terminology is also important: You want a Battery Minder or Battery Tender not a “trickle charger.” The latter term is often used expansively to cover both types of devices. Also, if you have an AGM battery you will want a Minder/Tender specifically for AGM batteries.

This, if you get tired of looking for the drain.

And, yes, it is reasonable(*) to assume that you will have less parasitic draw with the alarm off.

Aftermarket stereo or other add-on gizmos? Notorious for excessive current draw.

In terms of reasonable, this is true for the 9[89][12] generations. Those also have a “transport mode” that can be switched on with PIWIS (perhaps iCarSoft and Durametric too) that drastically reduces current draw. 996? Dunno.

Yeah I was thinking battery tender but instead called it a trickle charger.

I don't have any electronic aftermarket devices on the car. The only thing that should be drawing power now is the alarm.

I'll drive it and then leave it unlocked to see if it makes a difference. I'll look at my Durametric settings and see if there is any type of "sleep" mode I can put it in.

Thanks all!

[fpena944]

Took the 996 out today during lunch and it started right up!

It had been about two weeks since I last used it so whatever is drawing current from the battery is very slow and low (like BBQ!)

Maybe this is just a reminder to use it more often.

[lupo.sk]

install a very simple mechanical battery disconnector, essentially a big kill switch just like on racing cars. I use it on my polaris RZR, my friend uses it on his land rover defender and I know a fuckton of people with rarely used cars that do the same. charge battery, park, disconnect and enjoy life.

[fpena944]

install a very simple mechanical battery disconnector, essentially a big kill switch just like on racing cars. I use it on my polaris RZR, my friend uses it on his land rover defender and I know a fuckton of people with rarely used cars that do the same. charge battery, park, disconnect and enjoy life.

Now why didn't I think of that?!?

Only problem there is my radio presets and instrument settings will be gone but no big deal.

Edit - another problem is that I wouldn't want that switch in my interior and I'd want it by the battery. If I did that I wouldn't be able to open the trunk unless I use the mechanical bypass which is not ideal. Ok, back to the drawing board.

[milrad]

That is a nice little setup. But just trying to figure out how to then route an electric cord to where my car sits without having people trip over it since it would have to cross a walkway.

Tunnel under it and run the wire in a piece of conduit. Can't imagine a walkway is that thick/deep.

As far as a charger/maintainers, get a CTEK. I have a fleet of these things. I recommend the 5.0 or the 7002. Don't mess around with the other cheaper ones. You'll end up with a CTEK anyway.

[Flat6Noise]

My turbo is now doing the same thing. It never used to do it, but now it is. I replaced the battery to no avail. There has to be a phantom draw somewhere. I even tried disconnecting the aftermarket stereo amps and head unit. It’s still doing it. Battery Tender for now, but it’s still bugging me. And it must be contagious because my old beater truck is doing it now too. Replaced the battery on that too, but nothing changed. Still doing it. I hate electrical issues like this. They’re like a woman in a bad mood for no apparent reason. I don’t even know where to start.

[fpena944]

Tunnel under it and run the wire in a piece of conduit. Can't imagine a walkway is that thick/deep.

As far as a charger/maintainers, get a CTEK. I have a fleet of these things. I recommend the 5.0 or the 7002. Don't mess around with the other cheaper ones. You'll end up with a CTEK anyway.

Yeah the tunneling is easy but the closest electric outlet is on a raised porch and to the left of a door we use often. So I'd have to run an extension cord or hire an electrician to drill into the brick and place a new outlet on the other side of the house that is closer to the driveway.

I think what I'll do is just make sure to drive it more often or disconnect the battery when I know that I won't. The other options seem to be a little too much work.

My turbo is now doing the same thing. It never used to do it, but now it is. I replaced the battery to no avail. There has to be a phantom draw somewhere. I even tried disconnecting the aftermarket stereo amps and head unit. It’s still doing it. Battery Tender for now, but it’s still bugging me. And it must be contagious because my old beater truck is doing it now too. Replaced the battery on that too, but nothing changed. Still doing it. I hate electrical issues like this. They’re like a woman in a bad mood for no apparent reason. I don’t even know where to start.

I think I mentioned before but I had been in the market for a 996 turbo and in one instance the dealer kept theirs on a tender. So maybe this is something related to turbos? Although I can't see any difference between the electronics on a base 996 compared to a turbo so it should be the same.

Agree...electrical issues stink!

[amdavid]

Check alternator...

A corroded or defective alternator diode will faultily continue charging the circuit even when the car off. This, in turn, will drain your car battery and cause the car not to start....

[Flat6Noise]

I don’t think it’s just a turbo thing, Fernando. Mine never was like this before. Now it is.

Thanks for the tip on the alternator, AMDAVID. I’ll check that next.

I’m hoping to get that car out of storage and at home in the next couple of weeks. As weird as it may sound, I’m looking forward to working on it.