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Discussion Starter · #1 ·
Hello Everyone,

I recently purchased a very cherry 2012 Volt with 115k on the clock for a very low sum of money. Long story short the high voltage battery died on the previous owner (diagnosed by a professional GM mechanic) and he sold the car to me in the middle of August. When I picked up the car from the previous owners mechanic, the car was completely running and driving with no DTCs. Apparently, the mechanic had put the car into "default mode" or something of the like and fully charged the battery. I drove it for about a month with no real issues but I never let the battery drain below 50%. When the range got low, I would switch to mountain mode and keep driving.
Last weekend I decided to test the battery and ran it down to empty. Immediately the dreaded "reduced propulsion" error came up and the ICE engine started. When I parked it the car would not start again and leaves me with a MIL light for the high voltage battery and ICE engine interlock.
Realistically I need to replace the entire high voltage pack. There is one cell in module 1 that is outside of the set parameters for the rest of the pack and what is likely causing this fault. I recently purchased a VXC Nano scanner with GDS2 and Tech2Win but am having difficulty working through the software. Does anyone have any suggestions on charging the battery enough so that I can move the car in preparation for this battery swap?
Additionally, I need recommendations on used battery swaps. My current plan is to source a battery from car-part and do a home garage swap then reflash the computers with SDS to keep this a budget car. Should I swap in the same 2011-2012 1.4 battery chemisty? Or try to source a newer chemistry batteries with lower miles? Any input would be greatly appreciated. Thank you for reading.
 

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Why not just replace module 1 that has the low cell? Parts availability?
 

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Why not just replace module 1 that has the low cell? Parts availability?
Exactly. Individual modules haven't been available as replacements for a year or two now. It's been whole-battery or nothing.
 

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Discussion Starter · #4 ·
From what I understand, you cannot purchase the early generation module sections anymore and GM is actively replacing whole packs with the newer battery chemistry.
I can pickup a used 2011-2012 pack for around 1000 and a 2013-2015 pack for double that at 2000. Are the newer rocks any better and worth the extra money? I know it’s all a crapshoot really
 

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From what I understand, you cannot purchase the early generation module sections anymore and GM is actively replacing whole packs with the newer battery chemistry.
I can pickup a used 2011-2012 pack for around 1000 and a 2013-2015 pack for double that at 2000. Are the newer rocks any better and worth the extra money? I know it’s all a crapshoot really
The range on a 2013-2015 Volt was rated at 38 miles versus 35 for a 2011-2012. Some late 2012's have the 2013 battery. I have a 2012 with the 35 mile range. I don't remember the kwh difference. My 2012 has 155k miles on it and now only dissipates 8 kwh per full charge roughly. The resistance must be getting high because in the winter it sometimes switches to gas prior to draining the full charge.

Tough call, IMO. I'm pretty cheap. Might depend on how I would use the car as to which battery I would buy. I would probably buy a >2013 battery if I'm going to the trouble to replace it. Good luck.
 

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Hello Everyone,

I recently purchased a very cherry 2012 Volt with 115k on the clock for a very low sum of money. Long story short the high voltage battery died on the previous owner (diagnosed by a professional GM mechanic) and he sold the car to me in the middle of August. When I picked up the car from the previous owners mechanic, the car was completely running and driving with no DTCs. Apparently, the mechanic had put the car into "default mode" or something of the like and fully charged the battery. I drove it for about a month with no real issues but I never let the battery drain below 50%. When the range got low, I would switch to mountain mode and keep driving.
Last weekend I decided to test the battery and ran it down to empty. Immediately the dreaded "reduced propulsion" error came up and the ICE engine started. When I parked it the car would not start again and leaves me with a MIL light for the high voltage battery and ICE engine interlock.
Realistically I need to replace the entire high voltage pack. There is one cell in module 1 that is outside of the set parameters for the rest of the pack and what is likely causing this fault. I recently purchased a VXC Nano scanner with GDS2 and Tech2Win but am having difficulty working through the software. Does anyone have any suggestions on charging the battery enough so that I can move the car in preparation for this battery swap?
Additionally, I need recommendations on used battery swaps. My current plan is to source a battery from car-part and do a home garage swap then reflash the computers with SDS to keep this a budget car. Should I swap in the same 2011-2012 1.4 battery chemisty? Or try to source a newer chemistry batteries with lower miles? Any input would be greatly appreciated. Thank you for reading.
Apparantly the out of balance condition of the cell is a problem only when the battery has been fully depleted. The solution is to not let the battery get to that condition. GM engineering decided to “protect” the battery by having software declare that differences between cell voltages greater than 121mV require the “look-see” of a Voltec mechanic.

The least costly, and really simple approach, is to get into the same “default” mode and recharge the battery, then put the car in “Mountain Mode” before each drive thereafter, preventing complete depletion of the battery.

I would take the car back to the mechanic who did the magic and have him do it again. I’d rather put up with a battery that gets me ~20 miles down the road before firing up the on-board generator than to go through the hassle and expense of replacing the battery.

Just remember to always put the car in Mountain Mode before driving. That’s the only drawback to my solution.
 
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Finding a battery is not easy. Made several calls with no luck.
If you have a place or garage to keep the car and fix it, then replacing is a option till a good battery is found.

I have heard that the GM Gd2s software can be tricky to install. That’s a third hurdle.
The Volt dyi Facebook site has people that can help with the software. Brian B is one.

the Weber institute has some good videos. One is on this site above in freq questions

GOOD LUCK
 
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