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Im getting same on both apps ‘Battery Partially Charged’. Happened today.

a-ho... have you update your MercedesMe app ? get a voltage meter to test the voltage of battery. i tested after about 30min drive, i got 12.4v, but when i connected my charger, the voltage gose to 12.85, which is very good, from now on, i need to keep it connect it. otherwise, battery might become bad after 3-4 years
 

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I received the same warning from the new Mercedes app, it said to either charge or go for a drive if at least 30mins.
Due to poor health I hadn’t driven the car for several weeks so assumed it was that but checked with dealer and they said it was due to the car not being driven.
After getting home following a longish drive the App is now showing the battery is fine.

I have never had this issue with my previous Golfs with similar driving patterns as I work from home but will see how it goes.
 

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I received the same warning from the new Mercedes app, it said to either charge or go for a drive if at least 30mins.
Due to poor health I hadn’t driven the car for several weeks so assumed it was that but checked with dealer and they said it was due to the car not being driven.
After getting home following a longish drive the App is now showing the battery is fine.

I have never had this issue with my previous Golfs with similar driving patterns as I work from home but will see how it goes.

Mercedes car use a lot of power
 

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Permitting the weather I might take her out for a long drive. If not my work commute is approx 25 mins on M1 tomorrow.
 

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Will do now. Any recommendations?
Will do now. Any recommendations?
i got Ctek mus 4.3. you can search Ctek, it's a very good charger, when battery is full, it should show 12.8 v,

Ctek is the brand that MB or BMW dealer use, usually MB sells re-brand Ctek charger, put MB logo on it, but it's the same. Ctek is a Sweden company really good at making charger.
 

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Low battery indicators on app also an issue for me with C63s and A35. Bought a charger to top both up as app showing they need it if I don’t do a long drive each forthright. When new, both batteries were only charged to around 25 percent and needed to be charged overnight to get back to full charge. With lots of things using the battery when it is not running, load is running batteríes down much faster than my previous cars. Ok now with the charger, just something else to look out for. Expect to have to charge them after a few weeks of sitting idle, and you won’t get caught out again. First C63s battery was faulty and replaced under warranty as would not hold a charge properly according to the dealership.
 

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I made some interesting observations recently. Ever since I've owned my A250 (7 months) the battery gauge has shown 12+ volts when driving but 14+ volts when coasting (this is when the alternator is giving a higher voltage). From what I had read about these new fangle dangle charging systems this seemed to be right. Recently I got the battery voltage critical warning so charged the battery with my CTEK over night, now I have 14.1 to 14.5 volts under normal driving and up to 14.9 volts when coasting so it will be interesting to see what happens when (if) I do a bit of stop/start town driving again.
 

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To connect your CTEK leads to the battery was the cover easy to remove? I have noticed there is a positive only smaller cover....not sure why? Thanks
 

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To connect your CTEK leads to the battery was the cover easy to remove? I have noticed there is a positive only smaller cover....not sure why? Thanks
I would check the maunal for instructions but I pushed the red cover to one side and connected the red +ve clip and connected the black clip to the brass nut by the wing, I believe that this is the -ve ground point.
 

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I asked MB CS a couple of questions the other day and they have just got back to me:

1. How long should an A Class battery stay charged if the car is unused A. Don't know

2. What is the minimum voltage at which the car will start. A Don't know

3. Does the car enter a standby state when its critical voltage is reached A Don't know.

4. If the battery drains in three weeks or less how would you keep it charged at say an airport A. Use a trickle charger.

I pointed out that there is no power at car parks which flummoxed him

The chap apologised that he didn't have the technical knowledge to answer these questions but would pass it to the technical dept but didn't think they would know how long a car could be parked with a fully charged battery, I pointed out that it was a fairly easy calculation, Amp Hours of the battery divided by amps per hour used, not hard really :unsure:
 

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Discussion Starter #34
I made some interesting observations recently. Ever since I've owned my A250 (7 months) the battery gauge has shown 12+ volts when driving but 14+ volts when coasting (this is when the alternator is giving a higher voltage). From what I had read about these new fangle dangle charging systems this seemed to be right. Recently I got the battery voltage critical warning so charged the battery with my CTEK over night, now I have 14.1 to 14.5 volts under normal driving and up to 14.9 volts when coasting so it will be interesting to see what happens when (if) I do a bit of stop/start town driving again.
Mine was showing partially charged on the app, just taken it for a 30 minute 14 mile run
The display showed 14.8 up 14.9 coasting.
Now shows charged on app, but I know if I do a 1 mile Tesco run it will be back to Partially Charged, going to have to go the long way round!
I’ve previously left it and other cars at airport car parks for 15 days and never had a battery problem, but I would advise leaving the handbrake off
 

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I've left my cars at Heathrow for three weeks or more in the past without problems but as my battery went down to critical in 2.5 weeks I'm trying to get a bit more info out of MB, after all they designed and built the thing so they should be the best people to ask
 

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I've had the battery replaced under warranty 2 months ago, however today I'm getting the critical battery level warning on the app.
 

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I received this email from MB yesterday, “Supporting you during this time”,what does this mean :- you don’t need to charge the 12 volt battery, is that the 2nd battery?
Battery and charging.
If you are not using your car regularly, we recommend starting the engine and letting it run for a period of at least 15 minutes every two weeks. It is important to allow the engine to run for this long so the battery can charge properly. Be sure that your car is outside when the engine is running and don’t leave it unattended.​
Charge (SOC) should ideally be maintained at 50% and shouldn’t drop below 30%. You don’t need to charge the 12-volt battery as this is supported through charging of the High Voltage (HV) Battery.​
 

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I received this email from MB yesterday, “Supporting you during this time”,what does this mean :- you don’t need to charge the 12 volt battery, is that the 2nd battery?
Battery and charging.
If you are not using your car regularly, we recommend starting the engine and letting it run for a period of at least 15 minutes every two weeks. It is important to allow the engine to run for this long so the battery can charge properly. Be sure that your car is outside when the engine is running and don’t leave it unattended.​
Charge (SOC) should ideally be maintained at 50% and shouldn’t drop below 30%. You don’t need to charge the 12-volt battery as this is supported through charging of the High Voltage (HV) Battery.​
I also received this email, I have no idea what it means, are they are talking about an EV battery?
 

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I also received this email, I have no idea what it means, are they are talking about an EV battery?
I got the e mail too. Hadn't used the car for 3 weeks and the app was saying that the battery was charged. So today I did as the e mail suggested and started the car and let it tick over for 20 minutes. The app now says that the battery is partially charged!!!! Does that mean that MB's advice is wrong?
 

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Not sure about wrong but it's not good advice in my view

Firstly you shouldn't start a car and let it idle, especially when it's been standing for a while, you want oil pressure as quickly as possible so 2000 rpm would be good for a few seconds

Second letting it idle will fill the exhaust with wet gasses so you need to take it for a run so the exhaust gets hot and burns the wet off.

Third is similar to 2, if the engine doesn't get nice and hot the block will have condensation which will be absorbed by the oil.
 
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