Astur

I've recently retired and plan to take a 4 month hiatus traveling throughout Europe (mainly in Spain, my homeland) and as such the 1 year old Bosch battery on my 997.2 C2 will require trickle charging during this absence.

I've read some post regarding these hookups and see that most opt for some kind a of a direct connection to the battery terminals with a quick disconnect cable to the battery tender. However, I've noticed my car has a capped 12V plug on the passenger side of the center console. Hence, what would be your thoughts on connecting the battery tender via a modified fused plug like the one below?

Also your thoughts on placing a 3A Battery Tender (brand) inside the car and raised up above the carpeting for air flow and heat dissipation? The reason for this is that my carport is not totally enclosed (concrete lateral columns and inclined roof slab), so the tender could possibly get wet with some of our high wind torrential showers.

3Series

If you plug it into the car cabin, there is a slot in the passenger door where the cable can come out of. Its like a crush slot in the rubber seal.

I'd leave the charger outside of the cabin, put it under the frame so it's sheltered or near a tire.

MM3.9GT3

In my 997.1 GT3, I use the passenger side footwell power outlet. I have never had issues. As for leaving it inside the car, I have not done so.

red carrera

I leave mine plugged into the footwell outlet for months at a time with no issues. I run the cord under the door; the weatherstripping seals fine on the thin cord.

I don't like the idea of the charger being left inside the car though. There should be a way to fabricate some weather protection for the charger that won't draw attention to it.

Astur

Is a 3 amp Battery Tender (brand) adequate or should I be looking for a more higher output unit?

Philster

If it is this or similar, you are absolutely fine. Maintenance is straightforward, but the variables increase when you are charging up drained batteries, but this appears good either way.

FAQ: http://www.batterytender.com/Frequen...tions/#answer9

http://www.batterytender.com/Charger...ry-Tender.html


PN: 022-0202-DL-WH

Introducing the Battery Tender® 3Amp Power Plus! This fully automatic charger allows you to choose between 6V or 12V output while still providing all the reliability and efficiency you’ve come to expect from the Battery Tender® line of products.

Available ONLY at BATTERYTENDER.COM, COSTCO.COM and COSTCO retail locations.

Input: 120VAC @ 60 Hz
Output: 6V or 12V @ 3 amps
Reverse Polarity Protection to ensure user safety.
Spark Proof
Short Circuit Protected
Complete 4-step charging program (Initialization, Bulk Charge, Absorption Mode, Float Mode).
Safety timer: 72 hours
Perfect for all lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell).
5 year warranty
Listed in California Appliance Efficiency Database
Agency Approvals: UL/ RoHS / BC
$74.95
.







.

Astur

Thanks Philster!

That's exactly the one that I saw at a local COSTO and that goes for $39.99 over here.

ADias

Get a Ctek instead. have a better reputation and they do not overcook a battery. Also... you can connect to the cigarette lighter which is fused and is the port PAG suggests.

If your Bosch battery is AGM set the Ctek in the AGM (snowflake) setting.

speedracerf4i

I suggest to plug the terminals directly to the batteries terminal. then run the cord out from the base of the wind shield. There is a quick release that you can plug in and out in a jiffy. Super easy and safe.

SAN997

I don't think anything except a direct battery connection will work for you. On my car (2007 C2S), when the car is locked, after ~1 week, all of the relays switch off and the circuits are disconnected. This means that when you store your car, the cigarette lighter will disconnect from the battery after 1-2 weeks. Then your battery will self-discharge and die.

ltcjmramos

Good point about what happens on a locked car. Mine is in my garage, unlocked, and I've left the tender in the cigarette lighter for up to three months (ankle surgery incapacitated me) with no issues. I've had several other 2-3 week periods with the tender, no issues. But always unlocked.

Petza914

I thought for both using the air compressor and charging the battery via a power socket, you were supposed to use the one in the center console, not the one in the footwell. Do I have that backwards?

On my car, I wired a Battery Tender quick connector directly to the battery and then brought it out to the front smile grill for the 3rd radiator air egress. It's wire tied to one of the cross bars in the smile at the corner. I just flip it up when I need to plug it in and then cap it and push it down when I'm driving the car. You might be able to see it in this photo - driver's side corner of the smile grill.


May have to zoom in on the photo to see it.

Astur

Does anyone know if this is also true for 997.2's?

What's interesting is that you say that on a locked car "... all relays switch off and the circuits are disconnected." Wouldn't that in effect "erase" all user settings and require a re-programming/learning process?

Usually the typical cigarette lighter circuit is only fused and "always on" is it not? So I don't understand the relays part or why they would affect/control that circuit. Furthermore, why would Porsche go to the trouble of notching the passenger side door to accommodate the cable for in-cabin battery charging connection if it wouldn't work for extended periods of time?

Truthfully, I like the quick connect/disconnect convenience of the cigarette lighter connection but maybe not at the risk of coming home after my 4 month absence and find that the battery is dead because the tender couldn't do its job.

Petza914

The lighter socket in the ashtray is hot all the time (you can leave your phone charging there while the car is locked). This means it has a direct connection to the battery and probably at least a 5A fuse - which means your battery maintainer can charge through that port even with the car off and locked. That's the one I've been using on my wife's car for about 3 years. Also explains the notch in the weather-stripping so the wire can come out as the Porsche and CTEK chargers have a cord long enough to be plugged in there, but have the control module/charger unit outside the car.

Iceter

Keep in mind that even the Battery Tender warns against leaving the unit plugged in and charging for weeks at a time, just to avoid liability for overcharges and fires.

Also, RE. the unit in Philster's post--why would you need the ability to charge a 6V battery? I would think that Battery Tender's weather-sealed 12V unit would be just fine. See below:

http://www.walmart.com/ip/Battery-Te...f-800/15779499

I have one of these and use it up at the lake to keep the boat battery charged while we're not there. I also have the unit plugged into a light timer so that it runs only a few hours a day. I figured that this would reduce the chances of it overcharging the battery in case it malfunctioned.