c4-toy

I have the older OEM Porsche battery tender from my 993 w the cigarette adapter, is it safe to use in 991? Seems work to as the red light lights up, but I don't want to fry any electronics. Any concerns?

j080808

You are correct, and its not hidden. The front is a big Porsche sticker, the side says ctek on it. Amazing how the price of something doubles with a different sticker.

LexVan

I have the same ones. Used in my 993, 987, 997 and plan to use in my 991 when it arrives.

c4-toy

I don't know how these battery tenders work other than being plugged into outlet, Is it safe to use the older Porsche charge-o-mat on the 991?

Slantnose!

They supposedly have a chip in them that shuts it off, so no overcharge & turns on again when battery charge goes low.
Been using them forever...no problems, except if the power flicks as if in a storm I've noticed they start charging for some reason.

Chiboy

OK, I got the CTEK 3300 last night along with the cigarette lighter adaptor. After reading all the posts I could find, I did the following:

1) Plug into passenger footwell outlet
2) Run cord under driver's door
3) Close and lock doors with windows up
4) Plug in 3300 to wall
5) Set mode to "snowflake" since car is in detached, unheated garage here in Chicagoland and temperatures get below 41º

I don't really get why the car should be locked, except that it's such a great, great car that you should avail yourself of all the protection you can. ;-) But I did it. I'm slightly uncomfortable with closing the door on the wire, but it seems like plenty of others have done that with no ill effects, and I'd rather not have the window all the way down (necessary due to outlet placement in garage).

Thanks for all the advice.

LexVan

^ locking the car during storage forces the car into "sleep mode" after about 5 days. In sleep mode the car consumes less battery power.

John 996 TT Cab

I had one of these also and used it on several Porsche's. However, it gave up the ghost this year (got very hot but didn't produce a charge) so I went to the Porsche branded CTek's for my 991 and 996 TT.

Chiboy

Ah, thank you. That makes sense. Hopefully I won't have many five day periods without firing her up, but if the recent snow rates continue, I could spend the winter begging my wife to borrow her SUV.

LexVan

You'll know when it goes into sleep mode because the key fob won't work. Need to use the actual blade. I assume the 991 works this way like the 997.