Complete power drain
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 51
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From: Seattle, WA
2006 CLS55
Complete power drain
CLS55 134k miles. Couple days ago went to start the car and got small hesitation. Next day wouldn't start. No power to electronics at all and dash is dark Alternator? Or what should I start with and work my way down. I already bought a new battery just in case. Thank you all
Last edited by SlavShreds; Aug 31, 2022 at 03:38 PM.
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2006 CLS55 AMG, 2005 SLK 350 AMG
What is the battery charge level?
Have you fully charged the battery and seen what it will do?
Install the new battery and tried what it would do?
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 51
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From: Seattle, WA
2006 CLS55
I was a fool and didnt check battery level when it was acting up
battery has been fully charged
I was going to do that today, thank you for the valuable info as always
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 51
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From: Seattle, WA
2006 CLS55
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 51
Likes: 3
From: Seattle, WA
2006 CLS55
All new parts installed - no luck. New battery (after being installed with new alternator) now wont trickle charge past 12.6. Gremlin chasing time i guess but where to start?
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Thread Starter
Junior Member
Joined: Apr 2021
Posts: 51
Likes: 3
From: Seattle, WA
2006 CLS55
MBWorld Fanatic!
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From: Alexandria, VA
07 E63 AMG, 10 C63 AMG, 07 E63 Designo, 07 E350, 09 C300, 07 C230
I never needed one in the past, but I went ahead a purchase one for myself. As you never know.
Last edited by Yuille36; Sep 6, 2022 at 12:43 PM.
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 51
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From: Seattle, WA
2006 CLS55
A jumper box has been on my mind for a long time, will pull plug on it soon. I'm DIY to the max, esp on this car, but I just remembered I have 17k miles left on warranty so off to the shop she goes on Thursday morning. 2% manhood gone
Thread Starter
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From: Seattle, WA
2006 CLS55
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04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
Assuming no parasitic draw, a good multi stage charger will run the battery up to over 14V during saturation phase and end up in the storage/maintenance phase in the 13.1-ish range (usually temperature corrected). 12.6 isn't even fully charged for a lead acid.
Thread Starter
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From: Seattle, WA
2006 CLS55
If one has such a charger, would this be something one would do in my situation? Saturate past 14v & then try to crank?
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04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
No that won't do anything. When the charger deems the battery fully charged it ratchets back the voltage to a safe level for long term storage. I did have a battery with an internal short on my CTS-V and what I noticed one day was the charger was smoking hot and all it should have been doing was maintaining the slightest trickle current. Well, turns out it was working at full capacity (1.25A) just to maintain the 13.1-13.3V it wanted. That was a smoking gun for me to investigate either a power draw or a battery issue. Took battery out of the car and charged it (all you really have to do is disconnect the ground side and charge it). Same problem, so I knew it was a battery issue.
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 51
Likes: 3
From: Seattle, WA
2006 CLS55
No that won't do anything. When the charger deems the battery fully charged it ratchets back the voltage to a safe level for long term storage. I did have a battery with an internal short on my CTS-V and what I noticed one day was the charger was smoking hot and all it should have been doing was maintaining the slightest trickle current. Well, turns out it was working at full capacity (1.25A) just to maintain the 13.1-13.3V it wanted. That was a smoking gun for me to investigate either a power draw or a battery issue. Took battery out of the car and charged it (all you really have to do is disconnect the ground side and charge it). Same problem, so I knew it was a battery issue.
