Hi all - I have been using the Porsche-branded battery tender made by Ctek for the last several years with no issues on my 04 TT. This is the one that plugs directly into the cigarette lighter. Lately the tender is getting very hot to the touch fairly quickly when connected - any ideas why? The battery is not very old and I've never had problems with it cranking right up, even after sitting for a week or so.

I'm not comfortable using it when it gets this hot, so it's been sitting on a shelf. Before I buy a new one I wonder if I'm missing something easy to check first.

Thanks in advance!

 

this cant help much(?) but my ctek 3300 is usually "hot" after an overnighter, and it seems to work fine. i'm a bit dubious about leaving it connected via the cig adapter for long periods, and would use the eyelet or even the gator clips if i was keeping it connected longer than a quick trickle charge, so there is *proper* ventilation of the battery itself.

 

The hotness comes from resistance that has met the charger, this happens with all the CTEKs. If it were connected directly to the battery, that would mean heavy internal resistance in the battery and the charger is having to do a lot of work to "get through it" per say. Being plugged into the CL could mean wiring is growing old (has gotten hot possibly from over-current) and is losing its ability to distribute the current accordingly, and/or the battery is aging and getting the previously mentioned internal resistance. If you have a volt meter, I would suggest unplugging the charger and immediately checking the battery voltage at the terminals (record this number..even the numbers after the decimal- 1/10's of a volt matter). You want to see higher than 12.7 (just off the charger is typically right around 13). Then leave it off charge for a few days (without driving) and rechecking after every 2-3 days. If after a week your voltage is below 12.66, then you have 1 of 2 problems: 1) bad battery, needs to be replaced OR 2) battery needs to go on a manual charger to recover the charge that the CTEK us3300 won't do. If the later, also have your alternator tested.

 

^ good info. i just went thru the discovery process finally realizing that although the ctek seemed to be "working" it wasn't offering a "full" charge even though the indicator light suggested otherwise.

leaving me stranded waiting for a AAA battery truck recently lol

 

Don't know what kind of battery went bad but I've also experienced a fully charged battery easily start the car in the morning and then 2 hours later dead - when these batteries go bad they go quickly. Replaced battery and no problems since.

 

Do you have the 'comfort indicator through CLA' in the car? Or direct to battery?

Regardless...battery maintainers (which is what most chargers on the market are), don't do well in "charging". But as long as its on a new battery regularly, it helps a ton to eliminate battery problems. But there's always that 1 that rolls off the assembly line

 

I've been using the CTEK plug into the lighter charger for about 2 years. Since I only drive 1x per week, sometimes every other week, it's almost always plugged in.

It's *never* been hot to the touch. That would be cause for some concern.

 

i just use interstate 790 cca replacements because aaa brings em in a truck with tools but you're absolutely right. fine one minute, dead the next. i blame this of course on my not having had time to drive the car on a daily basis and i don't like the idea of leaving the ctek always connected.

oh yeah, lesson learned..

I'm gonna get a "real" charger/tender as the ctek - while a great must have item - is NOT a charger, but rather a "maintainer" as you know. now i KNOW the difference.

 

Mr. Ronson expains it correctly. The CTEK will get hot. Its all about the load you are putting on the unit. My tender usually gets very hot at initial plug in if I hadn't had it hooked up and the car has been sitting. It cools down dramatically when it goes into trickle mode (maintenance mode). This is all normal. Hooking to CL has never given me a problem. I have had mine hooked up for as long as a year without starting my car and it fires right up. My last P-CTEK lasted me 12 years. Probably should have changed it sometime ago due to loss of efficiency. At one time I noticed it was staying very hot and never changing to to maintenance mode and it turned out to be a bad battery. Unit could not keep up with charging of an already half dead battery.

 

Mine gets hot too, but cools off once it is in maintenance mode. However I use the CTEK non-Porsche US model with a quick connect plug that stays permanently attached to my battery with eyelet terminals. I just open the hood and plug in, charger is mounted to garage wall.

 

i'm begininng to wonder if my 3300 is shot from having overextended itself on my most recent half dead battery well, either way, i got my 75 dollars worth! that's for sure ha

 

I checked all fuses etc and all was good in the car, and never had any issue with the fairly new battery. I hooked up the tender again, and measured how long it was hot - turns out once it went into maintenance mode it cooled off quickly. Maybe I was freaking for nothing or my battery needed more of a charge than I thought and it caused the tender to get pretty hot, and I was disconnecting it too soon - as mentioned by several of the good folks on here. ��

 

Perfectly normal for tender to get hot. I leave mine unatended for long periods of time and never a problem. I do clance at the lighting seqence to make sure it is operating properly and always check my battery for the obvious signs (swelling). just recently hooked my tender up to another car with a dead battery and the battery swelled like a tick. I now I should not have used the tender for this because the tender IS NOT A CHARGER.... but I was lazy. Tender was operating fine but its use is for maintaining a healthy battery not for charging. If the haet is that much of an issue simply place it on a home made heatsink . Aluminum or copper is best.