ymc226

I've been using the Porsche Charge O Matic II (Ctek 3300) trickle charger since I got my 2007 GT3 new whenever I plan on not driving the car 4 or 5 days.

In the winter, I leave the charger plugged in (via cigarette lighter) 4 months as I don't drive it at all.

After the OEM battery died, my dealer suggested an Interstate Megatron Plus (MTP-91) using the same trickle charger.

For the last 2 occasions that I've used the charger, it has been unnaturally very hot to touch on the bottom (usually warm only). Today, I went to start the car and it was completely dead. Not even the dash lighted up.

Do you think the charger is at fault, killing the battery or vice versa?

ymc226

Sorry, another question. I've heard Optima batteries are better. Which Optima model would you suggest for a 2007 Mark I 997 GT3?

Larry Cable

I've never had any problems with the (same) trickle charger on both my '07 or '10 cars ...

D-Uber Cars

Maybe you don't have a complete connection via the lighter. Would suggest connection directly to the battery might be better.

bkcarrera

I had an an '05 C2S on the same charger as well as one on a '10GT3.
The one for the '05 all of the sudden became very warm - to the point I did not feel comfortable leaving it hooked up.
It was an oem battery. Rather than checking it out, I traded the '05 for a new Cayenne S. New battery probably would have been less.

I did purchase a couple of the yellow Granite Digitals - pretty neat - probably does the same thing but I love the voltage read out.

Larry Cable

sounds like the load (resistance) on the charger was higher causing it to overheat, perhaps a bad connection or a faulty battery?

seems like it may have been the latter ... have you taken the battery out and/or tried to charge it with a normal battery charger?

The Baron

I have my original batteries in both '07 (#2513 #3115)and my '08 RS(#2191) and have NEVER used a trickle charger on any of them.

When I finish driving one of them and I know that it will sit for more than 72 hours (which is often) I simple pop the hood and disconnect the ground wire to the negative terminal.

I rest the ground wire off to the side and rest the hood latch on a shop towel so that it can not close completely (hood opener is electric, remember...). I keep a 10mm wrench with the car.

No chance of screw-ups or mishaps or idiots tripping over wires !

This process takes 30 seconds and has worked very well for me........

I'm a firm believer in K.I.S.S.

axhoaxho

I wonder if that would trigger an airbag warning light (or something like that, I forgot exactly) after disconnecting and reconnecting the battery?

Regards,

The Baron

To date, my routine triggers nothing and has never triggered any codes, etc.

I have repeated this routine on all four of my RS (just started doing this on my '11 RS) since August 2007 and have never had a problem with radio station presets, PASM, etc.

Think about the nightmare for Porsche techs if your theory was reality. It would drive Porsche, Porsche dealers and Porsche mechanics mad.

It has worked flawlessly and I would recommend this over trickle chargers or tenders any day.

Larry Cable

I thought that would require you to re-enter the radio code ... I guess not!

axhoaxho

Thanks, that is good to know.

Regards,

ymc226

What does removing the ground terminal do to the status of the battery. I am getting ready to put away the car for the season and might try this.

ir_fuel

Your car consumes a tiny bit of power when not in use. After one week it shuts down even more of the electrical systems and you will not be able to open the door with the remote. But even then it still draws a very small current (for instance for the alarm). Leaving your car like this for 4 months will drain your battery. Disconnecting the battery will stop it from draining.

enthusiast

Try your battery maintainer on another vehicle and see how it performs.

My CTEK 3300 does get pretty darn warm on underside during heavy charge conditions.

The Baron

Anyone that is interested in my battery routine, here is the step by step process to protect the car;

1. Park car, turn off car.
2. Open hood with electric release in door sill
3. IMPORTANT - Open both doors slightly to cause windows to drop 1/4 inch. This is very important as windows will NOT drop automatically once battery is disconnected and with window in full UP position, you can NOT properly open and shut door.
4. disconnect negative terminal from battery and move to side.
5. IMPORTANT - Place folded shop towel over hood catch receiver so hood can NOT close completely. (This is a pain in the *** when if someone shuts your hood by accident)
6. Rest hood gently on shop towel.
7. Close both doors (windows slightly ajar and won't hit when closing).
8. When ready to re-use car, connect Negative terminal, remove shop towel, shut hood and go !

I do NOT own any trickle chargers and I have repeated this process hundreds of times on my three RS for +/- four years with NO ramifications.