GM Volt Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
Hi guys,
we started for a one week vacation 7 days ago. We took a drive for about 400 miles and used the battery only in towns, but the range extender engine on highways. We drove the last 200 miles through heavy rain, arrived safely and turned the car off for a week. Yesterday, when we tried to get back home, the 12V battery was dead at 7 volt. I had have a jump start, which worked out properly. Then we started for the 400 miles to get home, also through heavy rain. We were driving on engine and not on battery. After 3 hours we stopped for a break and the battery was dead again. Voltage 7V. So I needed another jump start. and decided to drive the last 50 miles on battery. While on battery the 12V system is obviously charged. While on engine/range extender, there is obviously no charge of the battery. Is there a fuse or a relay I have to check? Could it be about the rain? Anyone with the same experience? The battery is like 3 ys old. Thank you for any comment or suggestion.Wheather condition was cold in the mountains, about 40 degrees at night and 58 during the day. Vehicle was in a garage. I also experience, that the recuperation is lower than it was in former times.
Thank you
Thomas (Austria)
 

·
Registered
2014 Cadillac ELR
Joined
·
584 Posts
I believe the 12V IS charged while using the engine. What year do you have? 12V charging while plugged in is different on some years of gen 1.

However, I believe you simply have a bad 12v battery.
 

·
Registered
Joined
·
3,001 Posts
12v batteries can die in as little as three years, especially in hot climates. Replace the battery.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #4
Recharging the 12V battery with an external charger shows no problem. The battery stays fine and recharges, as long as I use only the HV system to drive. When I drive with the engine/range extender, the battery drains. The 12V will not be charged while the HV battery is plugged in and the car is turned off. I feel, there must be a fuse blown bringing the 14V power from the engine to the 12V battery.
 

·
Registered
2014 Cadillac ELR
Joined
·
584 Posts
Again: what year?

Simply recharging won't tell you if the battery is good. It needs a load test.

The 12V will not be charged while the HV battery is plugged in and the car is turned off. I feel, there must be a fuse blown bringing the 14V power from the engine to the 12V battery.
Pretty easy: connect a multimeter to the battery set to volts, go for a drive. You'll have your answer fast. Then, switch the meter to continuity, then probe each fuse. No beep on one? Pull fuse and inspect.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #6
Again: what year?

Simply recharging won't tell you if the battery is good. It needs a load test.



Pretty easy: connect a multimeter to the battery set to volts, go for a drive. You'll have your answer fast. Then, switch the meter to continuity, then probe each fuse. No beep on one? Pull fuse and inspect.
Model year is 2017, manufactured February 2016, new 12V starter battery in March 2018. It is working fine, as long as I drive electric, it runs empty driving on engine. We are talking about the 12V starter battery.
 

·
Registered
Joined
·
4,671 Posts
It should not matter whether the Volt is running on the high voltage battery (charge depletion mode) or on gas (charge sustaining mode.) The Volt has no alternator; all 12V power comes from the DC-DC inverter known as the Accessory Power Module (APM.) The APM is rated at ~2kW, runs all of the 12V accessories and charges the 12V AGM battery while the Volt is powered on. When the Volt is plugged in the on-board charger has a separate charging circuit that maintains the 12V AGM battery.
 
  • Like
Reactions: 4est

·
Registered
Joined
·
4,671 Posts
Maybe one of the 12V AGM battery terminal connections is loose. When running on the high voltage battery the connection to the 12V battery is poor; vibration from the ICE improves the connection of the 12V battery. Check the tightness of the 12V AGM battery terminal cables. Else, the 12V AGM battery is suspect even though it is just 3 years old.
 

·
Registered
Joined
·
195 Posts
I agree with jcanoe. It shouldn't matter running on battery or engine, the 12V charges the same. In your first post you mentioned a reading of 7V, that is EXTREMELY low, most likely enough that it will never charge properly.
 

·
Registered
Joined
·
61 Posts
The OP states: "While on battery the 12V system is obviously charged. While on engine/range extender, there is obviously no charge of the battery."

This is not obvious at all. The car ran fine while on range extender and ran fine while on the HV battery, so I don't see a difference in behavior between the two modes based on the information you posted. You won't know whether there is a difference unless you were running on battery and stopped to get coffee or something and see whether the 12V battery will restart the car after a break. And even if you did that, you won't really know whether there is a difference in 12V charging between the two modes because it sounds like you ran the car on the ICE for hours before turning it off but you can't do that with the HV battery because it doesn't have the ability to run the car for hours.
 

·
Registered
Joined
·
4,671 Posts
Sure it does; if you leave the Volt powered on while in Park the Volt will continue to stay powered on for 2.5 hours before it will automatically shut off. If the high voltage battery runs down during this time the gas engine would start. A fully charged or nearly fully charged high voltage battery pack could theoretically power the Volt for up to 14kWh/0.5kW = 28 hours. If the AC is running the the battery pack would discharge sooner.
 

·
Registered
Joined
·
38 Posts
Thomas,

Open the hatch to access the battery, remove the cover on top of the battery to gain access to the positive battery cable clamp. with a volt meter measure the battery. just checked my 2017 Volt and with the car off it reads 12.46 volts. Now step on the brake and turn the power on with accessories A/C, heater or something. Measure the battery now voltage should read 14+ volts. This is powered by the Volt Accessory Power Module. There is no alternator as in a regular car. If you have more than 14 volts under load the Accessory Power Module is doing it's job and battery is the culprit. an auto parts store with a load tester will tell you if you have a dead cell or internal battery connection issue. If you turn the Volt ignition on and you do not see at least 14 volts you have a problem with the car.

Stephen
 

·
Registered
Joined
·
17 Posts
7 volts is really low. The battery could have sulfated and won't hold charge. I've recovered some batteries by pulling them from the vehicle and connecting them to a smart desulfater for a few days. Of course that may not be practical unless you have one and have another backup car to drive.

That does not preclude that the underlying problem is the DC to DC converter that charges the battery in the car.
 

·
Registered
Joined
·
26 Posts
Thomas Ol'Boy!

I had a 2013. Did the same thing. 12V ran down. Jumped it. Worked for a day or two. Then dead in the garage. I swapped the battery temporarily with the battery in my TDI and boom, the Volt ran like a charm!

I hope it's just your battery. That's how it was for me. I bought an off brand AGM battery. Ran perfectly for another three years until I traded it for a Gen2.

(Off topic -- BIG Mistake. I wish I had the Gen1 back. It was a much better, quality-built car. The only good thing about the Gen2, imho, is the newer Voltec. Everything else is cheapo'ed, tinny, plastic, flimsy, in the worst way. Sigh.)

I assume yours is an Opel Ampera?
 
1 - 14 of 14 Posts
Top