Yes - the 12V battery is automatically recharged by the high-voltage battery
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That is probably true, I wonder if that update (forgot which version but it stated something along the lines of Update the module responsible for future module updates) was the prerequisite?
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Maybe the battery is bad and won't fully charge. They usually get really hot when that happens so maybe the BMS also monitors temp and stops charging it. Just guessin' though... should probably let the dealer diagnose since we're not even supposed to open the hood on these vehicles and would suck to void your warranty just to put a volt meter on it.
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Maybe the battery is bad and won't fully charge. They usually get really hot when that happens so maybe the BMS also monitors temp and stops charging it. Just guessin' though... should probably let the dealer diagnose since we're not even supposed to open the hood on these vehicles and would suck to void your warranty just to put a volt meter on it.
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BMS definitely broadcasts the high voltage battery status over CAN bus so maybe... I just have a regular OBD2 reader though and can't see that info. You'll need to get something like what Bjorn uses:
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BMS definitely broadcasts the high voltage battery status over CAN bus so maybe... I just have a regular OBD2 reader though and can't see that info. You'll need to get something like what Bjorn uses:
https://youtu.be/NA1Ygc19Qxk
https://youtu.be/NA1Ygc19Qxk
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Follow up to my 23 eqs 580 sedan which has been sitting in my garage since mid May. After 4 weeks the app still displays the 12 v battery as partially charged. Went to dealer today who stated unequivocally not to worry, car senses the battery is low and will maintain it so it doesn’t become fully discharged, as long as hi voltage battery remains charged( my SOC is 77%). I asked why doesn’t it fully charge it and was told it may not fully charge it but will keep it charged enough so it won’t brick the car. I’m not planning on using the car till the fall when I return to Florida so I hope he’s right.
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Follow up to my 23 eqs 580 sedan which has been sitting in my garage since mid May. After 4 weeks the app still displays the 12 v battery as partially charged. Went to dealer today who stated unequivocally not to worry, car senses the battery is low and will maintain it so it doesn’t become fully discharged, as long as hi voltage battery remains charged( my SOC is 77%). I asked why doesn’t it fully charge it and was told it may not fully charge it but will keep it charged enough so it won’t brick the car. I’m not planning on using the car till the fall when I return to Florida so I hope he’s right.
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Interestingly, I just had my car in for the three software safety recall updates. During this period, the car sent me messages that windows were open, the trunk was open and the ignition was on. The invoice also showed that the dealer had it hooked up to a battery charger for the 12V battery while doing the updates.
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Then if they don't know they should update it, I only heard positive feedback on the forums with E330.xx as it provides bug fixes and even quality of life improvements.
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I agree. Problem is my car in garaged in my Florida home and I summer in RI. I bought the car in RI (7th Mercedes from them) so I great service from them. The times I’ve had to use the dealer in north palm beach hasn’t been so accommodating.
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I see, not all dealerships are created equal.
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Sorry for the long story....just had to vent...
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From: New England/Florida
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Sorry to beat a dead horse but…… Car has been sitting in my Florida garage since May. I’m in RI. No trickle charger. Was told hi voltage battery will maintain 12v battery by dealership. Have monitored status thru app and was always “partially charged”. Downloaded latest Mercedes me app and status went to Low(red letters). Briefly went to critical. Got email warning I should charge the 12 v battery. No guarantee car will start. Just happens I am flying to Florida as we speak to check up on car and house. Called dealer. They have no idea why battery is not being maintained as they even printed out a sheet outlining how the hi voltage battery will maintain the 12 v battery in storage mode. Will arrive at house later tonight and see if car starts. Meantime dealer told me to put it on a trickle charger.
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No Mercedes yet
It's strange that some people (e.g., I) have been seeing the 12V battery getting automatically recharged by the high-voltage battery when the car is parked for a long time - and others have not. It would be nice to get some definitive information from MB about the reason for this (e.g., software versions). But, as usual, we can only speculate, because nobody from MB ever posts to this forum :-(
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Sorry to beat a dead horse but…… Car has been sitting in my Florida garage since May. I’m in RI. No trickle charger. Was told hi voltage battery will maintain 12v battery by dealership. Have monitored status thru app and was always “partially charged”. Downloaded latest Mercedes me app and status went to Low(red letters). Briefly went to critical. Got email warning I should charge the 12 v battery. No guarantee car will start. Just happens I am flying to Florida as we speak to check up on car and house. Called dealer. They have no idea why battery is not being maintained as they even printed out a sheet outlining how the hi voltage battery will maintain the 12 v battery in storage mode. Will arrive at house later tonight and see if car starts. Meantime dealer told me to put it on a trickle charger.
I though you already have been away from the car for a long time. If the car did not charge the 12 V battery at all, it would die after about a month if not charged and if the car was not set for hibernate mode. So I assume your car has been charging the 12 battery for some time. Odd if not any more.
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You don't mention the high voltage battery SOC. I assume it has plenty of charge as you don't mention it. At some point I'd assume the high voltage battery would get priority over the 12 V battery to protect the part. I have not seen the latest function descriptions for this but would expect automatic 12 V battery maintenance working down to at least 20 SOC of the high voltage battery, if it works in the first place.
I though you already have been away from the car for a long time. If the car did not charge the 12 V battery at all, it would die after about a month if not charged and if the car was not set for hibernate mode. So I assume your car has been charging the 12 battery for some time. Odd if not any more.
I though you already have been away from the car for a long time. If the car did not charge the 12 V battery at all, it would die after about a month if not charged and if the car was not set for hibernate mode. So I assume your car has been charging the 12 battery for some time. Odd if not any more.
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From: New England/Florida
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On another note, my car was built in July 22 and was delivered to me in mid December 22. So it sat for 5 months without being driven. I wonder how Mercedes kept the 12 v battery up to charge during those 5 months.
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These cars have a "deep hibernation mode", I cannot remember the correct name but during transport from the factory and during other long periods of long parking this mode is activated. I'm not sure how low the consumption then goes and if the car accepts 5 months parking without charging but we have machines at home that are operated only for about a month in a year and they survive 11 months without battery charging. These tools have a main switch that cuts off all current consumption (and a 140 Ah battery).
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From: New England/Florida
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Follow up to my car sitting in my Florida garage for the summer. As I said I went to Florida a month ago and drove the car to charge up the 12v battery. Everything worked fine. No warnings. Car now has been sitting unused for a little over a month since I went to Florida. Left it this time at 65% SOC and 12v battery as charged. 12 v battery has gone from charged to partially charged on 3 occasions. Every time within a day or so the 12v battery went back to fully charged state. The SOC has stayed rock solid at 65%. Don’t know what happened but now it’s working as advertised. Previously the SOC went down at least 1% each week and 12v never fully recharged. Not sure if something in the car was active all along causing a slight battery drain but it seems to be working as designed now.
