andrew c230k

I am having an issue with something draining my battery when the car sits. I have two batteries now the old one, which is inside right now being recharged... I have it connected to a multi-meter and overnight it didn't loose any voltage. I have had it tested a few times and they claim its still good.

However this battery was not maintained properly 3 of the 6 cells where more then 50% depleted... meaning that 50% of the water had disappeared from 3 cells I topped them up with distilled water and recharged it... the tester claimed it had the proper voltage and cranking amps.

Right now I have a new battery installed its hovering right around 11.9 V according to dyno mode on my car.

My car seems to not start if the battery drops below 10.7 V.

noodleman

maybe it's something to do with the backup camera you installed?

andrew c230k

I am wondering about that, but it worked fine till it got cold out, I had the car in at the dealer for a multipoint inspection of which I expected they would have checked the water level in the battery which they did not.

Only reason I noticed the water was low because when it didn't start the first time i went and checked the battery an noticed it was very low.

If the new battery drains down then I am going to pull the fuse on backup camera and see what happens.

Star diagnostics during the quick scan picks up nothing I don't know enough about it to know if there is a way to test for a drain like this.

ruthless

Did you install a power magic pro? A device which shuts the camera down if your battery reach's below a certain voltage. This is useful when the camera is left in parking mode.

If so maybe try reconfiguring it so it shuts off sooner. If your camera goes into parking mode and is on all the time then it will drain the battery.

andrew c230k

No I installed the Mercedes Benz oem camera to oem specifications. I took half the car apart to do it.

ruthless

O okay my bad, I thought it was one of those dash camera's.

roadtalontsi

most amgs have the vrla glass mat batteries which are sealed. What year is your car? also checking for voltage changes isnt going to help you figure out a problem. You really need to measure the rest current amperage draw. should be .060 amps or less. Also being that your car is keyless go, if your key is left in the car or in close proximity it can keep the system awake.

JimmyR

Not sure if this helps you but do you have a security tracking device fitted?? I had a similar problem to you on a previous car and it was eventually traced to a fault with the back up battery for the tracking device

Rsquad911

What year is your C63?

The OEM battery that came with mine is a sealed gel cell (no water filling possible)

Did you wire your camera to ACC or direct to constant "+"

I am Jeff

+1 on that. Definitely make sure you connected the camera to the reverse tail lamp, other wise you might have tapped onto constant on. That'll definitely drain your battery.

ZephyrAMG

^^^^ man these guys are good...nice job on the brainstorm fellas...

andrew c230k

I tried doing that test but I was unsuccessful following directions from the internet. Do you put the multimeter in series on the negative side or postive side?

My car is a 2008, all Mercedes batteries I have had have screws in the top to add water... My C63 already has had the oem battery replaced with an aftermarket same spec battery from carquest.

I went to walmart and bought a proper spec battery to find out if the battery was the issue.

My key is quite far away at least 50 feet.

andrew c230k

The previous owner had installed a boomerang gps tracking unit in the car which I was planning on removing but I forgot about it to be honest. Any idea where it is located so I can remove it.

andrew c230k

I don't think its sealed these newer type battery's just make accessing the area to fill hard, my new 2013 maufactured oem spec aftermarket battery no longer has the 6 screws in the top to access the water in the cell I have contact the manufacture to find out why they made the change. Also the new battery is about 10 lbs lighter then the old same size.

My camera is installed in the way that Mercedes would have from the factory I bought all oem parts and followed the retro fit instructions I have star diagnostics and wis to do these installs.

The camera get power from the rear sam and is triggered by the passenger side reverse light.

I am only thinking about the camera is causing a problem because the voltage converting module I purchased used... but it started happening a few months after the camera install when it started to get cold.

andrew c230k

Ok gents, I figure out why my multimeter was not getting any readings... someone blew the fuses.

So I finally was able to get a reading on the draw and I think its very high. I will post a picture of my multimeter I was unable to get it to get a reading in Milliamps, when I put the meter in 10A mode it finally worked, my trunk light turned on and was showing a draw of 1.0 -1.3 A which is no where near 0.05Ma?



So my understanding is I am suppose to turn my multimeter to Ma on the DC setting and move the red lead to the second spot from the left.

I was only able to get a reading when I turned it to 10A DC and move the red lead to the first spot 10A

JimmyR

Not sure sorry. For obvious reasons they are often well hidden, I knew where it was in my BMW as I watched the guy fit it. There should be some sort of receiver typically somewhere high up on the firewall - perhaps in the cabin ventilation on the motor side of the firewall - and if you find this and follow the wiring you should be able to locate the main unit and its back up battery pack etc.
I would be getting someone who knows the unit to remove it - often they are hard wired into the car's immobiliser and might have a built in "kill switch" feature which gets activated if it thinks it is being tampered with.
I'll bet this is what is draining your battery

motoman

[QUOTE=andrew c230k;5553577]Ok gents, I figure out why my multimeter was not getting any readings... someone blew the fuses.

So I finally was able to get a reading on the draw and I think its very high. I will post a picture of my multimeter I was unable to get it to get a reading in Milliamps, when I put the meter in 10A mode it finally worked, my trunk light turned on and was showing a draw of 1.0 -1.3 A which is no where near 0.05Ma?







































andrew, read the owner's manual of the vom and make sure you are using the correct fuse(s). Your text sounds right for the current set up, but your picture is for voltage. The fuses are easy to blow and (sometimes) expensive. For "parasitic" current measurement all switched consumables must be off (trunk lite must be off) , Key removed. The #7 above sounds about right for expected reading (60 milli amps). You should select "milliamps" on the dial to see milliamps, otherwise see an accurate figure in amps.

andrew c230k

I phoned the GPS tracking company the first thing out of the lady's mouth was is it draining your battery?

So it sounds like it might be the problem.

andrew c230k

Ok so I pulled the GPS tracking unit today... idiots... I hate when people cut into the factory wiring harness when there is a much easier installation option... I always say the mark of a good installer is when you remove his work and you cant tell anything is been installed.

However I think I finally sorted this multimeter out... the battery on GPS is showing 3.3 V and its supposed to a 6.0 V battery and its drawing about 100 Ma see this pic if I have finally done it right...