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Discussion Starter · #1 ·
Had my 2012 Electron for year and a half. Always plugged in when not in use. For the first time I found it completely dead. Traced the problem to the speedo screen staying backlit overnight and draining the 12V battery (see pic). Removing the cluster fuse is a workaround. Anybody had this or can suggest a proper fix? Thanks in advance : )
142232
 

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The tailgate failing to fully close can cause this as will having a key fob near the car. The spare is not in the car by accident is it?
Lock, walk away and leave the fob a little distant, return to see if it shuts down fully. The car should turn off the DIC shortly. Takes a few minutes.
 
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Discussion Starter · #3 ·
Thanks, Spiny. Tailgate shut tight no key within range. Cluster remains backlit when the car is powered down and locked.
 

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Looked at mine but its a My13, the DIC lights off is about 1 min after locking, keeping a key near the car has no effect.
I with @h8ten fully reset the electrics (battery disconnect for at least 15 mins to discharge all capacitors).
If that fails to work, just to eliminate outside interference see what happens when away from the house area. Something is keeping the car awake.
 
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Discussion Starter · #6 ·
Try disconnecting the negative battery terminal for half an hour or so (guessing the time but this should allow everything to drain down) and see if that resets anything.
Thanks, Ian. Trying this right now.
 

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Discussion Starter · #7 ·
Thanks for taking the trouble, Shiny. Good to know what SHOULD happen : )

The battery disconnect has fixed it just for now, thanks Ian, but thinking on, I have already left the car off the 12V battery overnight a few times this week to charge it and the problem returned.

At the moment it is sitting, 12V connected and plugged in to charge, and the screen is not lit - all good. But it was ok like this for 1-2 days this week but then died again, presumably after the screen turned on over night. Removing the cluster fuse seems to be a reliable way of protecting the 12V but not clear why the screen backlight is coming on randomly.

In terms of something waking the car up - it's garaged and nothing I know of has changed in its vicinity.

I'm wondering if it could be a bad earth - I'll have a look to see where the earth point is for the cluster.
 

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Is your 12V battery on the way out? All sorts of gremlins wake up after midnight if this drops below 12.0V. First sight of an 11.9 on my little meter plugged into the 12V aux socket, and I'm off to tayna for a new battery. The old one then goes into wife's C1 and works perfectly for ages!!!
 

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Thanks for taking the trouble, Shiny. Good to know what SHOULD happen : )

The battery disconnect has fixed it just for now, thanks Ian, but thinking on, I have already left the car off the 12V battery overnight a few times this week to charge it and the problem returned.

At the moment it is sitting, 12V connected and plugged in to charge, and the screen is not lit - all good. But it was ok like this for 1-2 days this week but then died again, presumably after the screen turned on over night. Removing the cluster fuse seems to be a reliable way of protecting the 12V but not clear why the screen backlight is coming on randomly.

In terms of something waking the car up - it's garaged and nothing I know of has changed in its vicinity.

I'm wondering if it could be a bad earth - I'll have a look to see where the earth point is for the cluster.
Some older Ampera models seem to charge the 12v battery only when the car is switched on. This means if you are not using the car very much the 12v battery may be running down. I have noticed more issues with 12v batteries in this forum since the start of this lockdown because many cars are sitting on drives unused.Plugging into the mains does not make any difference.
The later cars charge the 12v battery when plugged into the mains.
This is easy to check. Just measure the voltage at the 12v terminals when the car is plugged in to mains. If the voltage is 14 to 15v then the battery is charging. If it is only 12v then the battery is not charging and you have to either run the car or charge the battery separately with a tricle charger.
 

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Discussion Starter · #10 ·
Is your 12V battery on the way out? All sorts of gremlins wake up after midnight if this drops below 12.0V. First sight of an 11.9 on my little meter plugged into the 12V aux socket, and I'm off to tayna for a new battery. The old one then goes into wife's C1 and works perfectly for ages!!!
Thanks, Andy. It's a new battery that I put in since I got the car, so new in the last 18 months. It's a Bosch.
 

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Discussion Starter · #11 ·
Some older Ampera models seem to charge the 12v battery only when the car is switched on. This means if you are not using the car very much the 12v battery may be running down. I have noticed more issues with 12v batteries in this forum since the start of this lockdown because many cars are sitting on drives unused.Plugging into the mains does not make any difference.
The later cars charge the 12v battery when plugged into the mains.
This is easy to check. Just measure the voltage at the 12v terminals when the car is plugged in to mains. If the voltage is 14 to 15v then the battery is charging. If it is only 12v then the battery is not charging and you have to either run the car or charge the battery separately with a tricle charger.
Thanks, Sha22. That could be it, because it is sitting a lot of the time in lockdown. I will check whether the battery is charging when plugged in. Currently the car's been OK since Saturday with the cluster fuse IN. I'll pay close attention to the 12V charge level over the coming days.
 

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I'm sure it is a case that the early cars would only charge the 12 volt when the main traction battery was actively being charged so once it was full the 12 volt would not be charged any more. Later ones would to[ the 12 volt up if the car was plugged in.
 

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Discussion Starter · #13 ·
Ian H - you are right. I've just verified this. The 12V went up to 13.4V when first I plugged in the traction charge cable but 30 mins later once the traction battery was showing as charged (flashing green light on dash) the 12V battery charge was reading 12.4V. I think my problem was related to low charge levels on the 12V battery due to lack of use. Thanks for all your help!
 

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Later would be the MY2013 cars, these top up the 12v when plugged in not just when charging the traction battery. the My12 ones I believe do not. The plate on the car is no guide to the model year, use the buying guide to identify just what the car is if your not sure.
 
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Ampera aka IGOR
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Ian H - you are right. I've just verified this. The 12V went up to 13.4V when first I plugged in the traction charge cable but 30 mins later once the traction battery was showing as charged (flashing green light on dash) the 12V battery charge was reading 12.4V. I think my problem was related to low charge levels on the 12V battery due to lack of use. Thanks for all your help!
The battery may still be under warranty if you still have the receipt.
 

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Here is some information from the Volt forum on the "Battery Maintenance Mode" used on the 2013 and newer model year Volts.

GM Electronic Service Information said:
Battery Maintenance Mode is an automatic function that prevents deep discharge of the 12 V battery in specific circumstances. It is enabled when the drive motor battery charger cable is plugged into the hybrid/EV battery charger receptacle and the hybrid/EV battery pack is not being charged. Operation differs depending on whether the power mode is Vehicle Off or Vehicle in Service Mode.

While Vehicle Off, the 12 V battery is monitored at periodic intervals up to a maximum of 30 days. While Vehicle in Service Mode, the 12 V battery is monitored at periodic intervals up to a maximum of 60 hours. If voltage is low, the 12 V battery is charged by the battery charger using external power for up to four hours. This function is only intended to prevent a dead 12 V battery and does not provide a full charge. This is more efficient than continuously trickle charging, thus minimizing the usage of external power.

Under normal circumstances, with a battery that is charged when the vehicle is parked, Battery Maintenance Mode will simply monitor the voltage level, and no charging will be necessary. With Vehicle Off, Battery Maintenance Mode will maintain the 12 V battery for up to 30 days. For longer periods, refer to Owner Manual for instructions.
It's actually quite surprising how quickly the 12v battery will run down if the car is not used. The battery will probably self-discharge at around 10mA and the Ampera systems will add 20-30mA when 'powered down'. This from the service manual including the dodgy grammar.

142401


State of charge of the 12v battery is roughly related to its non-load voltage (ignoring temperature effects) so measuring this when it is off charge and has stabilised (that means give it an hour or two) will give you an idea of the condition of your 18 month old battery. If it is over 12.5v then it is 80% or better. At 12v it is passing the 50% mark and as @HandyAndy says as soon as 11 shows you are in danger territory for reliable operation of the vehicle systems. Cold weather just makes things worse.
 

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Discussion Starter · #17 ·
Thanks for posting the info, all. My 12V seems to be at about 12.5V when not used for a day. I think that's Ok. My "dead Ampera" problem seems to be that I let the 12V get low due to lack of use and then it went haywire. Has been fine since I have been more attentive to 12V charge level.
 
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