GM Volt Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I have read the manual about jump starting, and I see that you are supposed to use the contacts under the hood for jump starting the Volt, and the contacts in the cargo area for jump starting another car.

The manual warns you that you may damage the Volt if you try to jump start another car using the contacts under the hood, but it has no such warning about jump starting the Volt with the contacts in the back.

Does anyone know if there are issues with using the contacts in back for jump starting the Volt?

The reason I ask is because the Volt has no way to release the parking pawl when the battery is dead. This means that if you are parked head in, you cannot push the car out of a parking space so that normal jumper cables can reach under the hood. Jump starting using the contact in the rear would be very convenient.

Thanks for any knowledge.

--George
 

·
Administrator
Joined
·
20,198 Posts
If only we had a FAQ in the Newcomers forum on jump starting the Volt. :)


Newcomers to GM-VOLT.COM (See here for FAQs)
> A Newcomers Guide: Chevy Volt Tips & FAQ Index
> Battery, Charging, & Battery Managment System FAQ's
> Jump Starting the Volt (from under front hood, or under rear cargo deck?)

https://gm-volt.com/forum/showthread.php?18986-How-To-Jump-Start-the-Volt

Of course, the question is also answered in your owner's manual.
 

·
Moderator
Joined
·
8,680 Posts
I have read the manual about jump starting, and I see that you are supposed to use the contacts under the hood for jump starting the Volt, and the contacts in the cargo area for jump starting another car.

The manual warns you that you may damage the Volt if you try to jump start another car using the contacts under the hood, but it has no such warning about jump starting the Volt with the contacts in the back.

Does anyone know if there are issues with using the contacts in back for jump starting the Volt?

The reason I ask is because the Volt has no way to release the parking pawl when the battery is dead. This means that if you are parked head in, you cannot push the car out of a parking space so that normal jumper cables can reach under the hood. Jump starting using the contact in the rear would be very convenient.

Thanks for any knowledge.

--George
It won't cause any harm - but getting the hatch open without power on the car is quite an adventure, too. (It's possible. There's a door on the inside trim that can be opened and allows a screwdriver to release the hatch, once you crawl in.)

If you're just trying to get a broken Volt out of Park, you don't need a jump to do that - removing center console trim on the passenger side gives access to the solenoid that locks the shifter.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #4
Hi Steverino,

Actually the question I asked is not answered in the FAQ or in the owners manual. Walter's reply below says it is OK, so that might be a useful addition to the FAQ.

--George
 

·
Registered
Joined
·
6 Posts
Discussion Starter #5
It won't cause any harm - but getting the hatch open without power on the car is quite an adventure, too. (It's possible. There's a door on the inside trim that can be opened and allows a screwdriver to release the hatch, once you crawl in.)

If you're just trying to get a broken Volt out of Park, you don't need a jump to do that - removing center console trim on the passenger side gives access to the solenoid that locks the shifter.
Thanks, Walter. Very useful.

I love the Volt and appreciate many of the design choices, but GM choosing to not provide a shift lock release seem's down-right stupid. C'est la vie.

--George
 

·
Registered
Joined
·
3,590 Posts
Back is fine if you can get to it
AND you can convince who ever is helping you that the battery is REALLY in the back.

I really need to make a no power trunk open tool - been putting that off for 7 years :)
 

·
Administrator
Joined
·
20,198 Posts
I really need to make a no power trunk open tool - been putting that off for 7 years :)

Already on the market and sold as, "Wide Blade Screwdriver" :)

If you have a screw diver hex shaft to square socket adapter, one of those may work too.
 

·
Registered
Joined
·
3,090 Posts
The front terminals are there because even if there is no 12V battery, you can still open the hood without issue. You cannot however open the trunk without climbing in with a screw driver.
And as others have said, using a battery jumper rather than cables is a much more convenient and safer alternative.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #10
The front terminals are there because even if there is no 12V battery, you can still open the hood without issue. You cannot however open the trunk without climbing in with a screw driver.
And as others have said, using a battery jumper rather than cables is a much more convenient and safer alternative.
Thanks, emartin00. It may be difficult to get the rear open, but that is infinitely preferred to getting the car towed if all you have is normal jumper cables and you are parked head in with people on both sides.

The real problem is that GM failed to provide a shift-lock release, which would allow you to simply back the car out and then jump to the front. It was stated above that you can remove the center console trim on the passenger side to hack this, but that is ridiculous when most cars (that I've had) allow you to simply stick a key into a slot by the shifter. Big fail on GM's part.

But the general consensus here is that you *can* jump to the rear, so all you need is to get the trunk open which sounds easier than taking the center console apart. That's potentially extremely useful, so I'm glad I asked here.

--George
 

·
Registered
Joined
·
3,590 Posts
All that being said:

the possibility of getting the positive jumper cable to drop on a fused outgoing cable from the bracket plate is a bit higher in the back.

Those small flat brown devices (Automotive Bolt-Down Fuse)- (depending on battery charge) they could blow when the current tries going back into the battery. Same problem if road side service in the dark decides not to connect to battery post and is poking about the plate to clamp on.

if you can get the Volt started there is 200 amps ready to re-charge the 12 volt battery.

According to one of the service manuals if the 12 volt batter is not in some correct voltage range it will not charge.

Would think it is testing for open or shorted cells - But if battery was just a drained a short external charge and a car restart
should get charging going.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #13
But if battery was just a drained a short external charge and a car restart
should get charging going.
So I've heard. People have said that you can jump-start a Volt with just 8 D cells (to make 12 volts). Don't need any cranking amps, just need to get the computers to boot.

--George
 

·
Registered
Joined
·
3,090 Posts
Thanks, Cord. That is incredibly helpful. Should be in the manual.

--George
Manufacturers tend to avoid telling you to jump directly from the battery for safety reasons. Batteries can off-gas hydrogen, which could cause a fire if the battery clamps spark. The AGM battery in the Volt should avoid that hazard in most conditions though.
 

·
Registered
Joined
·
1,634 Posts
Keep in mind that when you use your Volt to jump start another vehicle’s engine, you’re using the Volt’s battery to crank over the other car’s starter motor. That’s not what you’re doing when the vehicle that needs to be jump started is your Volt.

As described in the owner’s manual (nearly identical language in the Gen 1 and Gen 2 manuals), after you have the other vehicle’s battery connected to the terminals in the Volt:

"Press the POWER button to start. This will wake up the electronics on the Volt. After the instrument cluster initializes, the Volt will use power from the high voltage battery to charge the 12-volt battery. The jumper cables can then be disconnected."

The Volt’s "starter motor" is the smaller motor, MGA. Once the high voltage battery is available, the Volt’s gas engine is started in the normal manner (if you switch into Hold or fully deplete the battery, MGA spins the engine to start it, after which the engine cranks MGA to generate electricity).

It seems reasonable to think that "jump starting" the Volt from the terminals in the hatch area would also provide sufficient current to wake up the electronics. Locating a set of terminals for such use under the hood makes it easier when a dead 12-volt battery prevents you from unlatching the cargo hatch.

Since the process doesn’t require a current draw heavy enough to spin a starter motor, one would think you could create a "Volt jump starter kit" consisting of a small 12-volt transformer attached to a long extension cord that could be plugged into any 120 volt outlet in the parking garage where your Volt is sitting because it needs to be jump-started. What about a flashlight-sized gadget holding 8 D cells?
 

·
Registered
Joined
·
4,764 Posts

·
Registered
Joined
·
3,590 Posts
I see little point in the front hood terminals having ANY path or connection to the 12 volt battery.
That is start the car/computer ONLY.

At least with the fuses in the front you may not get the 200 AMPS 15 VOLTS back into your D cell device after the car starts.

Would be interesting to know what the development engineers decided in the early design days.
Guess they decided a wire was easier then another hatch release.



-----
As a friend of mine that has his own tow truck said to me " I am a tow truck driver why do I need a volt meter"
 

·
Moderator
Joined
·
8,680 Posts
I see little point in the front hood terminals having ANY path or connection to the 12 volt battery.
That is start the car/computer ONLY.

At least with the fuses in the front you may not get the 200 AMPS 15 VOLTS back into your D cell device after the car starts.

Would be interesting to know what the development engineers decided in the early design days.
Guess they decided a wire was easier then another hatch release.



-----
As a friend of mine that has his own tow truck said to me " I am a tow truck driver why do I need a volt meter"
Remember, a lot of design decisions were made based on making the car feel familiar/normal, like the big physical shifter and blended brakes. Having the principal means of jumping the car under the hood might have been part of that.
 

·
Registered
Joined
·
974 Posts
Greetings Dogvomit (what kind by the way? yellow vile? a hair ball? a chewed up doll? or dog toy? etc ..),

Manuals are always good to refer to but here are some of my thoughts.
If you are connecting your car to another car to help jump start the other car, then I would want the connection on my Volt to be at my 12V battery per the manual recommendations because, I don't know how big a load the other car might pose to my car. Could be really high, because of cold conditions, or the other car has a bad cell in its battery. Connecting directly to my Volt 12 V battery, guarantees high battery amps go more directly too the load without the risk of blowing a fuse somewhere in my car.

Now, I could make the same case for starting my Volt but in reverse. The case would be if my 12 V battery in my Volt had a bad cell. This could be the cause of a major inrush of current into my Volt 12V battery. If this is going to happen then I want the battery jumpers from the other car directly on my batteries. Same reason as above really. If I tie to the front of the car then there is the long run to the back with smaller gauge wire and a fuse some where in the link that might blow.

I really think the starting connectors under the hood are there for some convenience and like someone said, to sort of mimic what old style cars do now. If all you have is a low battery and nothing is broken and you need a jump, then the front should work fine.

I have a couple of tools in my Volt that I would use in the case I was stranded. One tool is a 12V adapter meter that shows the voltage on the 12V battery, and the other is a lithium jump starter. I would use the voltage check to determine how badly drained the 12 V battery is before I plugged in a jump starter. If it was too low, perhaps under 12 V, I would probably want to jump directly to the Volt's 12 V battery. The lithium jump starters have limits on what they will do also. If you have a major problem like a dead cell you may need a bigger jump starter.

Below you can see that an AGM battery below 11.8 V at no load is in really bad shape.

battery_specs.jpg
 

·
Registered
Joined
·
4,011 Posts
Greetings Dogvomit (what kind by the way? yellow vile? a hair ball? a chewed up doll? or dog toy? etc ..),

Manuals are always good to refer to but here are some of my thoughts.
If you are connecting your car to another car to help jump start the other car, then I would want the connection on my Volt to be at my 12V battery per the manual recommendations because, I don't know how big a load the other car might pose to my car. Could be really high, because of cold conditions, or the other car has a bad cell in its battery. Connecting directly to my Volt 12 V battery, guarantees high battery amps go more directly too the load without the risk of blowing a fuse somewhere in my car.
Bingo. At 12 v and 200 amps, you're losing as much as half a volt for every 10 feet extra that current has to flow. If it has to go all the way up to the front of the car, then turn over a V8...
 
1 - 20 of 20 Posts
Top