Mercedes R230 SL55 AMG battery drain + how to remove tracker

[@bigdog7813]

Cheers from the US. Excellent video showing and describing exactly what to do and why. Really appreciate you taking the time to record your work and share with the rest of us (especially the R230 community). I for one don't have the funds to hand over to my local MB dealership, so I try to self-maintain as much as I can. Videos like yours helps me stretch my retirement money. Am currently battling the dreaded red battery workshop warning display after replacing both the convenience and starting batteries. Thank you!!

[@MikesMercsandothercars]

Thanks for your comment. Did you have the red warning light BEFORE your swapped both batteries? If not, make sure you connect the batteries up in right order. Starter first THEN CONSUMER...otherwise you may get the red light. Mike

[@bigdog7813]

@@MikesMercsandothercars Thanks for the reply. Yes, I plan to follow your battery sequencing instructions once I get my car out of winter storage in month or so. Will let you know if this solves the problem - fingers crossed... 🤞

[@jeanjean376]

I have same problem, Always losing m'y accesories After 3 or 4 days.... Was you SL installed a tracker from the Factory, or the previous owner did ?

[@bigdog7813]

@@jeanjean376 Not sure.

[@mhyahiyaalrifai]

Thank you sir Can u imagine few days back I was not able to soft close the rear lid ?? I just removed the fuse as I remeber your video for 10 second and put it back Suddenly it's working ☺️

[@MikesMercsandothercars]

Phew....glad you got it working. Mike

[@MrFrobbo]

Great video and I would suspect strongly any batteries in equipment which are around 10 years and older. I also identified a similar battery pack in my Honda Accord alarm draining the main battery. Ended up replacing them in the alarm and all good. Thanks for all your hard work videoing and sharing.

[@MikesMercsandothercars]

Thanks for your kind comments. Mike

[@Billy-xw8uu]

Massive appreciations, sorted out my battery drain, it was the tracker and amess of wires that merc benz definately wouldn't leave about.

[@MikesMercsandothercars]

Glad the video helped...I discovered a couple of additional battery drains after I removed the tracker but hopefully your problem is fixed first time round. Mike

[@coolcat23]

What a beautiful car and thanks for pointing out clip locations, etc. I own a different Mercedes (A209) but it is always nice to see someone making such helpful videos. The replacement fuse meter is a very nice product but it occurred to me that it should be possible to modify a (potentially blown) fuse so that it can be connected to a standard ampere meter. To bad that your Mercedes dealer could not figure out the issue. They really should have been able to track down the problem by measuring current at the fuses, for instance.

[@MikesMercsandothercars]

Thanks for your comment. You might be interested to watch the video below. At 12min the video mentions the pros and cons of measuring current at the top of fuses: kzbin.info/www/bejne/poKvaqJvjq-bbLc Mike

[@coolcat23]

@@MikesMercsandothercars Thanks for the pointer. In this other video you are talking about measuring minute *voltages* across intact fuses, though. What I meant was to either take a broken fuse or cut the connection within an intact one and then measure the *current* (as opposed to the voltage).

[@MikesMercsandothercars]

​@@coolcat23 Yes - I think you could modify a blade fuse to work in conjunction with a voltmeter to measure current. The only downside/problem with that method, is that it wont help you find a non fused battery draw like a broken glove box light. Mike

[@celts153]

Good job ! Theses cars are very sensitive to low battery… and especially the front battery which is never changed… there is also a specific ECU dedicated to share current between 2 battery… theses cars needs 2 good condition battery in order not to have electronic problems. Fuse tester is a very good idea, I discover that 👍

[@MikesMercsandothercars]

Thanks for your comment. Interesting what you say about sensitivity to the front battery - I wonder what goes through this battery other than the starter motor? As I sat in the car this morning with the engine running o charge up the consumer battery and get rid of message, I could hear various modules come to life as the voltage hit certain levels. I wonder what the order of events is when a battery runs down..eg which modules shut off first and which come back to life last as the battery charges up. It was not until, the consumer battery error was gone that my windows went all the way up and my mirrors folded in again. It really is like learning a whole new language. Mike

[@celts153]

@@MikesMercsandothercars the small battery in the front is only here for a power reserve to the SBC system (brake by wire, which is an other particularly on this car… not the best one, but an other story). You are right, when the power module detect a power decrease, it shut some module, or put them in basic mode (like automatic heater). The problem with your windoWs are certainly due to disconnecting the battery, windows needs again to learn end of curse sensor (same with folding reverse miror, and also ESP), that’s normal.

[@barryd4131]

Great video, useful tools. My old r230 had drain from the front SAM, where the keyless go was beaconing and waking up the front SAM. As keyless go wasn’t fitted the garage cut the feed wire. Problem solved. Bug bill to track it down though…

[@MikesMercsandothercars]

Thanks for your comment. I still have a battery drain and reckon it could well be one of the SAM's or possibly error in battery control unit. This car has Keyless go. I plan to do a video on it...but finding that pesky drain. What was your diagnosis bill? Might quote it in the video to encourage people to do their own diagnosis. Mike

[@barryd4131]

@@MikesMercsandothercars £500 worth of investigation hours, in their defence checking fuses didn’t find the problem, so they had to go deeper.

[@MikesMercsandothercars]

@@barryd4131 Yep....that sounds about right. I can imagine that finding that fault took some time. Wish me luck! Mike

[@mhyahiyaalrifai]

This is genuinely genius

[@MikesMercsandothercars]

Thanks for your comment. Mike

[@dominicwood3750]

Note the online battery sellers list a stop start battery for the auxiliary. Don’t buy it as they fail if fully discharged. Just buy a cheaper standard lead acid like Lion.

[@MikesMercsandothercars]

No...DO NOT buy a lead acid battery for the consumer battery. Buy a good quality AGM battery. The charging profile for lead acid if different to AGM - different currents and different voltages. Y0u can potentially damage your very expensive BCM if you dont use the correct battery. You might be interested to watch the video below: kzbin.info/www/bejne/iqSco5KFbcmBjK8 Mike

[@dominicwood3750]

Thanks for fast reply. If you are 100% I will delete my comment. I read that the AGM had warranty void if discharged to a certain level, with the usual drain I assumed that would be reached sooner or later… I actually killed the battery at LeMans were it was running a camping fridge. Were AGM batteries available 20 years ago?

[@MikesMercsandothercars]

@@dominicwood3750 AGM batteries are specifically designed to be charged and discharged...whereas you will potentially kill a standard lead acid battery quickly by discharging it beyond a certain point. If you leave either type of battery in a discharged state for any period of time, you will ruin them. Yes AGM batteries were around 20 years ago and this is what came in the R230. A good AGM battery should last 2 -3 weeks without triggering the consumer message in the R230. These days camper van fridges like the CRX 50 are pretty efficient - we use an Ecoflow delta lithium battery for our van at festival. Mike

[@rickybridgeman1]

Great video! Would it also be possible to just unplug that tracker battery box plug so the tracker battery cannot draw from the aux battery to charge any more? And just leave everything else in there as is?

[@MikesMercsandothercars]

That might work...you just need to check that the tracker isn't ALSO wired directly to the battery in some way. The tracker battery is just a backup in case the car is stolen and the car battery is removed or runs flat. Mike

[@peterrobinson7421]

Mike Just a real thank you for the share. Brilliant If you ever about il buy you a pint or two. Best regards Peter

[@MikesMercsandothercars]

My pleasure...there are a few 'battery drain videos' in the SL55 playlist. In addition to the tracker unit, the glove box light and the mobile phone cradle have been culprits. Also worth watching the 'How to avoid ruining your battery' video as it is often the case that R230 consumer batteries are ruined by leaving them under charged...due to a battery drain problem. You can always click on the 'Thanks' button next to the Thumbs Up button...not quite the same as a pint...but probably works out cheaper! Mike

[@TheoSmith249]

What if you were to install a switch on the hot side of the device? remove SIM. then you have ready system.?

[@MrFrobbo]

Can you simply disconnect the ground on the consumer batt if not in use for a while and rely on the real key for drivers lock? I wonder if that would dissble the alarm or/and drain the internal alarm battery as alarms often have similar internal batt packs which cause high drain currents when over 10 years?

[@MikesMercsandothercars]

Disconnecting the consumer battery would work…..provided it was fully charged when disconnected. Any stored settings would be wiped. Not sure about the battery. Mike

[@MDavidG1]

What was the catastrophic battery drain (described at the end of the video) which necessitated using the key blade to get in the car?

[@MikesMercsandothercars]

Thanks for your comment - I'm not sure what caused the drain. I put the car back together last night (less the tracker and all associated wiring and peripherals) and went to the garage just now to check whether the same thing happened. Thankfully not - ran the car for 10 minutes to fully charge battery and everything working as normal. The previous evening, the battery had drained down to 7.5v. That evening I had taken the tracker and battery home (but left all wiring speaker and arial attached). The side panel was off and the blade fuse reader was left plugged in. Maybe unplugging the tracker and battery somehow caused the drain?...Maybe having the blade fuse tester plugged in caused the drain...although that seems unlikely as there was no current through that fuse. Maybe taking the panel off activates some sensor as I had a red roll bar message on the dash. Mike

[@PoppysGuitar]

Amazing vid. What is a "tracker"????

[@MikesMercsandothercars]

Thanks for your comment. It transpired that this car had multiple battery drains including the glove box light. A tracker is a a device with its own built in SIM card which allows you pinpoint the location of a vehicle or to be notified if the vehicle is moved. These days there are much more modern (better) alternatives. A super cheap option is just to hide an apple air tag in the car - if someone steals the car you should be able to get an idea of where it is. Mike

[@avinstallations]

When I bought my 2003 SL55, back in 2008, I took over the contract for the tracker, had the sim changed. The tracking device for my car is located elsewhere in the car. My car doesn't appear to suffer from a major battery drain, however, it takes around 3 weeks of not being driven, before the "consumer battery offline" message shows. I think this is normal. Curiously, is there any reason why you didn't just replace the battery pack and sim for the tracker? Would that not be a useful thing to have - especially for a reduction in insurance premiums?

[@MikesMercsandothercars]

Thanks for your comment. It transpires that the tracker was not the sole cause of the battery drain. Hopefully I'll shortly be doing another video on how to track down the other culprit. The tracker contract had expired when I bought the car. These days, you can just put in an Apple Airtag for £25 and it will usually be able to find your car....without the cost (and potential hassle) of the tracker. My 280SL which just got stolen and dumped had an Airtag....which would have been fine if they had just stolen the car and not dumped it in a stream. Do you still have your car? Mike

[@tombiondi9969]

Great video, thanks

[@MikesMercsandothercars]

Thanks for your comment - I'll be doing a follow up because it transpires the tracker was not the only drain. Mike

[@duncanbroughton8535]

What was the final draw on the battery after the tracker was removed?

[@MikesMercsandothercars]

Thanks for your comment. I didn't realise it at the time but the tracker was one of two things that was draining the battery. If you look at 11.27 iin the video below, you will see that the draw AFTER removing the tracker but BEFORE fixing the glove box light was something over 200mA. kzbin.info/www/bejne/poKvaqJvjq-bbLc&t The draw on a sitting R230 which is fully asleep with no issues should be about 55mA. Mike

[@tonymontana4349]

Brilliant

[@MikesMercsandothercars]

Thanks for your comment. Mike

[@robertthrossell4321]

Gr8 video

[@MikesMercsandothercars]

Thanks for your comment. There are 2 other 'battery drain' videos for this SL55....just in case you have the same issue. Mike

[@hk-bj8ph]

Hi Mike, been watching your videos and I hope you can help me! Iv changed the consumer battery in the rear and I'm still getting the battery warning sign on start up. Car doesn't respond to the central locking and the radio doesn't work. What should I be doing next?

[@MikesMercsandothercars]

What country are you in? Do you have a scanner or a clamp meter? Mike

[@hk-bj8ph]

@@MikesMercsandothercars thanks for the reply. I'm in the UK, I've replaced alternator, both batteries are getting correct charge. However, key is not being recognised, radio not working. Also replaced main 100A fuse in the passenger footwell. Thanks

[@MikesMercsandothercars]

@@hk-bj8ph Hello - Can you confirm that you are getting a red battery warning light on the dash at start up? If so, the most common reason for this is that the starter battery was not connected up in the right order. When replacing the starter battery (or disconnecting it for any reason) you must FIRST disconnect the consumer battery in the rear. With both batteries disconnected, you must FIRST connect the starter battery and THEN the consumer battery. You'll get the red battery warning light if you don't do this. Another reason for the red battery light is a faulty battery control unit (Part no. A 230 540 0945). This is the silver box located in the boot and shown at 12.24 in my ABC fault fix video: kzbin.info/www/bejne/i3anhZubZZV1eck Let me know exactly what problems you are still getting...or is it just the central locking and radio. Mike

[@hk-bj8ph]

@@MikesMercsandothercars yes I can confirm I am getting the red battery visit workshop light. I will follow the correct sequence you have described and see if it makes a difference. Regarding the battery control unit, this is an expensive part! Do you have any recommendations for what important parts yo service. Mine is a 2003 black sl55 with 91k on the clock! In addition to this, I have noticed radio and central locking do not work, also boot not opening. The trim behind the head rest next to the window is peeling but otherwise the interior isn't too bad. The key is never recognised. At 1.5 thousand revs car also shakes a bit, might be the exhaust or misfire. Lots of things to fix before the summer! Also enjoy watching your videos and great to see you put the time in!

[@MikesMercsandothercars]

@@hk-bj8ph 3questions: 1. Let me know the disconnecting both batteries and reconnecting them in the right order makes a difference. 2. Do you have a car scanner like the iCarsoft which throws up any codes? 3. Do you mean by the boot opening button on the door card is not working 4. Have any of these items ever worked or were they not working when youb giot the car? Mike

[@asankovlogs]

Sl500 no heat blowing. Just cold. Only to face. No legs even if selected. After 10 day driving alerneyor not charging now… help?

[@MikesMercsandothercars]

Hi sorry to hear you are having problems with your SL500. Is it R230 or R107 shape? Did you recently buy this car or have these problem just started? Mike

[@asankovlogs]

@@MikesMercsandothercars r230. I bought it like that.I just realized that i am missing several fuses…

[@asankovlogs]

@@MikesMercsandothercars hello

[@MikesMercsandothercars]

There are often several empty fuse sockets for the R230 - if you have a look at the video below at 4.58: kzbin.info/www/bejne/qqWrcpt9a6yLqNU And this video at 11.45: kzbin.info/www/bejne/poKvaqJvjq-bbLc This video shows the fuse chart at 22.05: kzbin.info/www/bejne/npuzoql3oKeAqsU How do you know your alternator is not charging versus having a knackered battery? Mike

[@TS-gd4pl]

Could you have just unplugged the tracker's battery instead of a full removal?

[@MikesMercsandothercars]

Thanks for your comment - In theory, I cant see why that wouldn't work. Mike

[@m60kaf]

That battery should be an AGM

[@MikesMercsandothercars]

Thanks for your comment. You are quite right and very observant -as mentioned at 46s in the video below, 2 types of battery in the R230: kzbin.info/www/bejne/iGjJk4R4hcaHhs0&list From memory, I think I was borrowing the battery from the red 280SL project car. You probably already know this, but AGM batteries have a better cycle life than lead acid. They can be charged 4-5 times faster which is quite important in the context of a consumer battery which experiences heavy loads from power hungry applications like the roof. They are also less prone to sulphation if not regularly topped up. Many R230's are parked up for months at a time and the consumer will die even more quickly if you use lead acid battery. Mike

[@erichknodel4334]

Disconnect the stupid SOS and your battery will be fine. You’re welcome

[@MikesMercsandothercars]

Thanks for your comment. Yes the “SOS” system is another potential drain but this system doesn’t exists in every country. Where are you based? Mike

[@terrenceg3257]

How to disconnect sos?

[@erichknodel4334]

@@terrenceg3257 Need to locate the fuse and just pull it. Not sure why it drains the battery but once the tech disconnected it everything was fine

[@sonhello9692]

This tuy talk too much

[@MikesMercsandothercars]

That's just what my wife says...If you have a battery drain issue on your car, there are a couple of other videos that might help you: kzbin.info/www/bejne/qqWrcpt9a6yLqNU kzbin.info/www/bejne/poKvaqJvjq-bbLc kzbin.info/www/bejne/hYjVeoZmnrx9gqM kzbin.info/www/bejne/lYPZoWuEj9RoY6M Mike