imtheking

2003 SL500

Walked out this morning and heard a ticking noise coming from under the hood. Couldn't open the car door with my fob- didn't take the key out to manually open the door afraid the alarm would go on nonstop at 6am and wake up the neighbors.

Last time this happened on on my S class, the battery was dead after sitting for a long time. Will probably need to jump the car when I get home

Today I bought a CTEK trickle charger from Amazon- but not sure which battery this needs to be connected to- the one under the hood or the trunk? to keep the car juiced up....or do i need to buy 2? one for the front and one for back battery?

EDIT- its the one in the trunk
Thanks

I also have the adapter that you can use to plug it into the cigarette lighter.

V12inRI

Can you post the model you got that's compatible w ur car? I just got an 05 SL600 and am looking for one myself.

imtheking

ctek 3300

model- 56-158

https://smartercharger.com/collectio...-multi-us-3300

get it on amazon for $50

danaw007

I only use my ctek tender on the consumer battery, the starter battery under the hood merely starts the car and doesn't hesitate even after sitting all winter.

imtheking

I used it for the first time today and after 3 hours, I unplugged it. My driveway is far from the closest electrical outlet in the house so I ran a 50 feet 16gauge extension cord from the house to the trunk of the car. Plugged in the ctek charger and walked away- went back after 3 hours and the ctek charger was HOT. I'm not sure I'm going to be able to leave this thing in the trunk with it closed in 90 degree weather.

Trying to find an alternate method to keep this cool as possible. CTEk only sells extension cords that are 8ft long. That still isn't long enough for me.

Anyone else here use an extension cord? leave the charger in the trunk- winter is probably ok- charger will love the cool weather- not to much in summer

whoover

The extension cord should be fine. If it's hot, it must be bulk-charging a fair amount of current. It's probably okay but make sure you have the correct program for you battery type. What phase was it in?

Frederick NL

Perhaps put it on a brick, more or less tight, to help the warmth dissipate.

imtheking

I left it behind the tire last night and let it charge overnight (11pm-8am). I set it to the highest mode- this is what I'm hearing is the recommended setting for AGM batteries. After 9 hours, the battery was still not fully charged.

I drove it to work today but will go back in "storage" tomorrow. I'll keep the charger connected for a few days and see if it finally fully charges- if not maybe an issue with the battery

danaw007

It should be on the snowflake setting. I don’t leave mine in the trunk. I route it out the weather stripping and let it hang by the tire, using a microfiber to protect the finish from the cord. I park in my garage with no extension cord though and it’s never been hot. I have used extension cords for other battery tenders without issues.

imtheking

Yes, last night I had it on the snowflake setting and ran it through the weather strip and down behind the tire on the cement. When I came out this morning, the unit was not hot

I'm reading other forums and people are saying it could take 18-24 hours to fully charge.

Good advice- I think I will place it above the tire and try to cover that area as much as I can to protect it from rain

danaw007

Im sure it would be fine placed on top of the tire. Good idea.

imtheking

Yea, maybe above the tire inside a plastic bag.....

whoover

It can actually take a couple of days. Before you replace the battery, you might want to invest in a CTEK upgrade. One like this not only can deliver more current, but does a better job reconditioning older batteries and displays which of the 8 modes it's in (the 3300 has 4 modes). That way you know if the battery is still accepting charge or if, after analysis, the charger says it's a goner. It also has a setting specifically for AGM, not just "cold weather and might as well use it for AGM too."

imtheking

Order placed! Thanks for this. I'll return the old 3300 back to Amazon