[Lucky1]

Hi, I have a CTEK MUS 4.3 POLAR charger which I use on my 2015 Porsche 911 Carrera 4S.

Someone told me it is not safe to use this trickle charger indoors (in my garage) on my car for long term winter storage and that it is safe for outdoor use only. Said this is due to the amperage being high (4.3 vs 3.3 on my other CTEK). I always leave it on snowflake winter trickle mode.

Anybody know whether this is true or not and the safe way to operate it for long term winter storage? I did e-mail CTEK for comment.

[///M Power-Belgium]

Originally Posted by Lucky1

Hi, I have a CTEK MUS 4.3 POLAR charger which I use on my 2015 Porsche 911 Carrera 4S.

Someone told me it is not safe to use this trickle charger indoors (in my garage) on my car for long term winter storage and that it is safe for outdoor use only. Said this is due to the amperage being high (4.3 vs 3.3 on my other CTEK). I always leave it on snowflake winter trickle mode.

Anybody know whether this is true or not and the safe way to operate it for long term winter storage? I did e-mail CTEK for comment.

As far as I know is CTEK the best and safest battery charger on the market , by his smart charge mode .
Never got issues in the last 7 years regarding my CTEK in my garage during weekends and entire winters .
I highly recommend CTEK

[Lucky1]

Originally Posted by ///M Power-Belgium

As far as I know is CTEK the best and safest battery charger on the market , by his smart charge mode .
Never got issues in the last 7 years regarding my CTEK in my garage during weekends and entire winters .
I highly recommend CTEK

Thanks! I know all about CTEK's reputation and that they are very popular with the automotive enthusiast crowd. My question was specific as to whether this exact model of CTEK charger is safe for prolonged indoor garage use as I'm being told the amperage on it is too high and will bubble the battery if not used outdoors.

[///M Power-Belgium]

Originally Posted by Lucky1

Thanks! I know all about CTEK's reputation and that they are very popular with the automotive enthusiast crowd. My question was specific as to whether this exact model of CTEK charger is safe for prolonged indoor garage use as I'm being told the amperage on it is too high and will bubble the battery if not used outdoors.

As I said the CTEK is a smart charger . The charger knows and feels how to charge your battery regarding the voltage and doesn't over-charge your battery .
CTEK is also used and sold by BMW . But with a BMW brand sticker on it ...
Mate .I'm pretty sure it's just fine

[PYE46M3]

Ive had a MUS 4.3 hooked up to my E46 M3 year round for 3+ years now... including subzero MI temperatures and no problems. just make sure you dont hook it up directly to the battery on the E92 M3, use the connections in the engine bay. I also recommend getting the MXS 5, its cheaper and does the same.

[Gossypiboma]

Originally Posted by PYE46M3

Ive had a MUS 4.3 hooked up to my E46 M3 year round for 3+ years now... including subzero MI temperatures and no problems. just make sure you dont hook it up directly to the battery on the E92 M3, use the connections in the engine bay. I also recommend getting the MXS 5, its cheaper and does the same.

Same, it should be fine in your garage.

[Lucky1]

Thanks. Just realized even the new CTEK chargers are all 4.3 amps even the MXS 5.0. So do think we're good here. The Polar cold edition I have is different in cabling and micro processor for cold weather charging. Max amperage is the same.

What about charging under a closed hood with a car cover on? I've done for three years. There are warnings in the box that say batteries vent gas and proper ventilation is needed...

[martin mustang]

I use 2 CTEK both from main dealers, one from branded BMW for my 635 and one from Porsche for my 911, the Porsche branded one plug into the cigarette lighter, used both for the last 3 years with no problems, they have built in security to cut off of the battery is no good.

[XMetal]

Originally Posted by Lucky1

What about charging under a closed hood with a car cover on? I've done for three years. There are warnings in the box that say batteries vent gas and proper ventilation is needed...

All batteries vent at or near overcharge. If the charger is properly designed, this should be kept to a minimum. Besides, that's what the vent hole and tube is for. Haven't you (we) been charging in a closed "hood" environment all this time since the battery is in a closed trunk?

[Lucky1]

Originally Posted by XMetal

All batteries vent at or near overcharge. If the charger is properly designed, this should be kept to a minimum. Besides, that's what the vent hole and tube is for. Haven't you (we) been charging in a closed "hood" environment all this time since the battery is in a closed trunk?

Thanks for that. Yes I have always done it this way. Good to have the discussion; when someone challenges what you have always assumed to be correct and makes you question it I try to go back and do the research to reconfirm previous held beliefs.

I see lots of people perpetuating old beliefs or myths who never question them or learn new ways. My parents jump a battery direct on the positive/negative terminal; how do I convince them to use the ground terminal for negative connection for example? As per your argument they've ALWAYS done it this way and nothing has gone wrong, right? Therefore by that logic that must be the right way to do it!

[MikeHawk7]

Should be absolutely fine even for long-term storage. I use a CTEK MXS 5.0 and found it way better than a Battery Tender, especially for extended long-term (years are no problem). Steps 7 and 8 are magic with it's Pulse and Float Maintenance modes.