How to Use Charge-O-Mat Battery Charger

I purchased the CTEK Charge-O-Mat Battery Charger from my Porsche dealer, but I'm confused as to how to use it. The first pages of the manual seem to say I should remove the battery from the car, clean terminals, add distilled water, etc. But then there is a section that seems to say all I have to do is plug one end into the cigarette lighter, plug the other end into the power socket, and turn it on and put it in CAR mode. I asked my salesman and he said that's all I needed to do. He said it was " plug and play" and I could leave it plugged in all winter if I wanted. Does anyone know anything about this particular charger? I'd hate to plug it in the cigarette lighter, then the wall and find out later I've caused damage to the car.

I use mine all the time and plug it into the lighter and then the wall (reverse to unplug) with no problem. Be sure and put it in the "car" mode. I don't use it when there are storms around because of lightning. I just need to get a surge protector that fits into my ceiling mount which would be a good addition when left unattended. Mine was on for several months during last winters snow and worked great.

Thanks, Santa Fe Thanks for that quick reply. I'll give it a try because I'm having shoulder surgery at the beginning of December, and with the recovery and harsh weather, might not be able to drive again until March. Do you think I should plug it into some kind of Surge Protector and not straight into the wall socket in the garage. Could my car be damaged if I don't have a surge protector?

The surge protector is a good idea I think, although it is still on my "to do" list because I made a ceiling mount for my charger and I need to re-design my mount for it.

For some reason, mine don't seem to work in the cigarette lighter but works fine in the socket in the little console. The lighter works fine so dunno why. Maybe its a switched outlet.

Oops. Correct Chow. I use mine in the socket not the lighter as well. Thanks.

Phew ... I knew that was switched

If you read your owners manual carefully, it says NOT to use the cig. lighter socket for anything other than the lighter. I use the one in the center arm rest for my charger.

This is correct. It specifically says only to use it for the tire compressor. The other sockets are not switched.

Well I can tell you that the Air Compressor does work when plugged into the lighter. I tried to make sure it worked once. And that I've used the tender plugged into the console socket since new in 2/06 with no problems. Hope that helps.

Did I Do it Wrong Here's the situation. Before having shoulder surgery yesterday, I plugged in the CTEK Charge-O-Mat, and covered the car. Believe me, it will be difficult to uncover the car and redo this process if I did wrong. Also, before beginning this process, I noted on Page 2 of the Instruction booklet, the first sentence of the Introduction reads:"The Charge-O-Mat is a primary switch mode battery charger with pulse maintenance for your Porsche . Page 7 of this same booklet gives instructions for "Connecting the charger using the cigarette lighter socket ." Based on these two sentences, I presumed that plugging the Charge-O-Mat into the cigarette lighter was the proper method. Here's what is happening: Sunday, I plugged in the Charge-O-Mat (first the cigarette lighter, then the wall socket), and set it to Automobile. The Automobile light turned Green , and the Charging Process Button turned Green . Monday morning I looked at it and the Automobile light was Green and the Pulse Maintenance light was Green . Today (Tuesday), I ventured out into the garage to make sure everything was working and noticed that the Automobile Light was Red (the manual calls it Orange, but it looks Red to me), and the Pulse Maintenance Light was Red . A few minutes later, I looked again and the Automobile Light was Red and the Charging Process Light was Red . Is this working or not working? The booklet (see page 10) seems to suggest that the Red Light is used when either the Voltage is Less than 12.9 Volts, or the Current is less than 0.5 amps. And the Green light shows that the Voltage is over 12.9 volts, or the Current is greater than 0.5 amps. The booklet makes no mention of what a Red Light for Automobile means. Question #1: The dealer told me to plug the thing into the cigarette lighter, which I did. Was that a mistake? The other socket in that flip-top area seemed far to small to accept this plug. Plus, as I noted above, the booklet for this device talks about using the cigarette lighter. Question #2: Is there a problem for the Automobile Light to be showing Red? I await your replies. I want to get this straight before I do something that might damage the car or drain the battery.

Normal is for the Auto light to be orange/red and when fully charged the Battery light to be green . Sometimes it takes a day or so for the battery to achieve a full charge. I use (and I am using it now with 6 inches of snow on the ground) the consol socket but you can use the lighter socket. The only thing that I can think of that could to wrong is that the plug may not be well seated in the lighter socket. And the only way to check is to unwrap everything and see. However you might want to wait a day to see if the battery light turns green and stays that way. I am now using the consol plug and not the lighter. Good luck.

Santa Fe: Follow Up Questions I'm pretty sure that the plug is well seated in the cigarette lighter socket. I pushed down pretty hard and it felt snug. Plus, for the first two days, the Charger and Maintenance buttons were Green . Only today did they turn Red . How could they switch from Green to Red if the car hasn't been moved or turned on?? Why did the Automobile button show Green the first two days, and now Red ? You mentioned that Red was normal for the Automobile button. Does Green indicate a problem? Thanks in advance.

I don't recall ever seeing the Auto light green. Are you certain?

New Information Santa Fe: I thought I saw it Green , but maybe the general anesthesia yesterday wiped out my memory. Now I'm thinking it Only shows Red for the motorcycle or automobile buttons on the bottom row. Anyway, I just rechecked and now the Auto light is Red (I'm concluding it will show only Red) and the Maintenance Button is Green . So I guess what this means is the the car was charging and maintaining in a cycle, but now it doesn't need to run the maintenance cycle and all is well. That's a total guess, but it sounds right.

Sounds right to me. Glad you are back from the surgery.

Very informative thread, guys. For what it's worth, on my CTek charger , the auto light is only ever orange. It's the charging/maintainer lights that switch between orange and green. I've been plugging my charger into the socket in the passenger console/footwell. Based on this discussion, I'm going to continue to do that. It's a snug fit, and you have to really push to get the adapter into the socket. In my (two weeks worth of) experience, once it's fully charged (i.e., orange auto light, green maintainer light), there will be times that the charger cycles back to charging (i.e., orange auto light, orange charging light). Those cycles don't last very long, since the battery nearly has a full charge, and just needs to be maintained from time to time as the accessories draw voltage. If you notice your charger goes back the charging state after achieving a full charge, you might just want to come back in a couple of hours to see if it's back to maintenance mode.

Simple, the car always draws power, especially if its locked with the alarm on. The whole point of the charger is to maintain the battery and that is exactly what it's doing. When the voltage dropped to a certain point, turned red. It showed green because all was fine, the voltage was above a certain level. I have noticed that sometimes it seems to never got to green but if you turn it off then back on, it immediately goes to green (and then back to red as needed). It sounds like it working fine.

Which model CTek charger do you guys own. I've been on Ctek 's website and I'm a little confused. In one place it says I can use the 800, in another it recommends the 3600. I'm looking to buy one soon (like yesterday) as it's a bit icy with plenty of salt on the road right now. Your help would be greatly appreciated.

I have the Ctek that Porsche sells (you can look it up at one of the Porsche sponsors) and one like sponsor Boothe sells. Both work great however the one Ralph Boothe sells is much cheaper. I do like the convenience of plugging it into the socket rather than wiring the battery but either is fine.

This discussion is about the Porsche branded charger made by Ctek. See Suncoast Porsche, Audi, & VW: Dual-Mode Battery Charger Although the Boothe Charger is cheaper, I see two differences (if I get this wrong, someone can correct me): The Porsche charger lets you just plug it into the cigarette lighter. No messing around with opening the bonnet and wiring stuff to the battery. Much easier for lazy people like me. The Porsche charger is more powerful. More power means less time to get to a fully charger state. Less time means less work for me.

I bought my non- Porsche -branded Ctek charger at the Porsche dealership where I got my car. For what it's worth, the parts guy said it has the same specs as the Porsche charger. The base unit looks almost identical - the only differences being the logo and the color of the "On" button. The Ctek unit costs 30% less because it's not Porsche branded. Take a look and see for yourself: Porsche Branded: Suncoast Porsche, Audi, & VW: Dual-Mode Battery Charger Ctek Branded: Ctek Porsche, Audi, & VW: Dual-Mode Battery Charger Actually, the main difference I see is that the cable coming out of the unit is different between the two. The Porsche one appears to have a fixed cigarette lighter adapter. The Standard Ctek unit has a plastic quick change fitting (white in the picture) that allows you to interchange the adapters. My Ctek charger came with alligator clips and also round connectors that can be attached to the battery terminals. A cigarette lighter adapter is also available separately (it looks exactly like the one on the Porsche charger). The combined cost for my Ctek charger and three adapters (hard wire, alligator clips, cigarette lighter) was $80.

Thanks for the help. I see by the picture that the Porsche unit is equal to the XS 3600.

Retired-Teach , I just double-checked my charger. It's the Multi US 3300 . Not sure what the difference is between that and the XS 3600, but visually the units look identical (except for the model number). I've updated the pic in my earlier post. The US 3300 is available for about $70 on various web sites, plus you'll want the cigarette lighter adapter which is roughly another $10.

Cayman S , It seems that the model sold here in the U.S. is the US3300. I ordered it today online and the adaptor as well. chows4us, Looks like the Porsche model is either equivalent to the 800 model or the 3300 without cold option.

Chows , great catch. You're right - My charger does includes a low temperature setting and has the ability to handle batteries like Optimas. I'd assumed that the Porsche branded model did as well. Oh, did I mention the US 3300 is 30% less expensive than the Porsche branded one, is made by the same company , and has more adapters to boot? I owe my dealer a thank you for selling me this one instead of the more expensive and less functional Porsche branded unit. Retired-Teach , glad my post helped and that you were able to order one for yourself. I think you'll really like it.

Hi Guys, Interesting and very helpful post, I have a 08, 911 C4S with a dead battery in my garage, I left the key inside the car for about 7 hours and when I noticed it was too late, the battery is completely dead! Few questions: 1 - Is it normal for battery to go dead so quick? 2 - Is it normal for batter to get eaten up when the car key left in despite it is on off position? 3 - And lastly if I buy the Charge-O-Mat Battery Charger can it help bring up a fully dead battery ? or is it just for maintaining a live batter? Thanks in advanced. Al

If it's a 2008 model you may be able to get the battery replaced under warranty. Certainly worth a try if it continues to give problems. The battery will probably recover once its been recharged, but the CTEK unit is really designed to maintain a battery rather than fully charge it from flat. If you can get the car jump started and drive for a few hours , then the battery will probably recharge from the alternator without issue. There are plenty of electronics that drain the battery with the ignition on , so im not surprised the battery died. Porsche offer 70 and 80 Ah battery options on the 911 and boxster , so its worth checking this. You can buy the CTEK 3600unit at a much cheaper price than the Charge-o-mat badged Porsche item.