[plugh]

I need to temporarily disconnect the negative terminal of the 12V battery.
(Unexpected issue with installing an EVEXTEND kit - pic attached)

If I use jumper cables to the engine compartment jump points (car off, not charging) will that prevent a reset / reboot of the various systems? (Car is 2014 MY)

 

[ClarksonCote]

You shouldn’t have to disconnect the negative terminal. It should maintain connectivity even with the nut in your photo removed to install the negative wire from the kit.

 

[plugh]

I'm not comfortable with using that screw. Not enough surface area contact for the potential current, and it being the tensioner for the connector seems risky to me. My current plan is to remove the terminal and drill a hole / add a bolt between the ribs, which should allow larger contact area without compromising connector's bending strength (much). I see you replied to my email, so I'll continue this discussion (and the other items) there.

Still looking for an answer to my question (which may be of general interest)...

 

[volt spain]

Use a lithium battery starter, while playing with the 12V battery,,,by the way great to have under the seat in the case the 12V battery goes down !!!.(plenty of them in Amazon for less then $100.)

 

[turboguy327]

It won’t hurt anything if you disconnect it. A power loss isn’t a big deal.

 

[DMC5180]

It won’t hurt anything if you disconnect it. A power loss isn’t a big deal.

I seem to recall it will reset all the user config settings back to factory default settings and clears all stored MIL codes if present.

 

[Arcanox]

The jump points under the hood should pretty much be direct connections back to the battery (except for a fuse) so you should be able attach a battery maintainer or jumper pack to those and disconnect the 12V leads

 

[plugh]

Thanks Arcanox! Logically I couldn't think of any reason why what I'm asking wouldn't work, but I don't have wiring diagrams or in-depth knowledge of Volt systems. I mean, it's just another source point for 12V into the car (fused? interesting), right?

re: other replies - Lots of unknowns (to me) of disconnecting 12V - Will I loose trip odometers? Efficiency stats? Radio settings? Clock? Sirius auth, OnStar enable, config settings, wheel / tire pressure associations, etc etc... Don't know, so the easiest path is just avoid it, keep it alive, using resources on hand (jumper cables).

Side note: Besides the hassle factor dealing with an unknown set of 'redos', two I really don't want to loose are the trip odometers. Trip A currently reflects the total life of the car (~226 gal, 178 mpg), Trip B since I bought it (~8 gal, 150mpg - gotta work on that). Not the end of the world if they get reset, but really cool to have.

 

[freshcut]

Disconnecting the battery only looses radio settings (time, station presets, etc). I'm pretty sure your personal preferences stay set such as your cord theft alert, door lock/unlock settings, etc but not the end of the world if it resets those. It does not however affect odometers, tire sensors, etc. I know this for certain as I have disconnected mine a couple times and I still have trip B set from when I reset at the beginning of the year (accurate total annual mileage) and trip A for my actual mileage/tank.

 

[Aseras]

Disconnecting the battery only looses radio settings (time, station presets, etc). I'm pretty sure your personal preferences stay set such as your cord theft alert, door lock/unlock settings, etc but not the end of the world if it resets those. It does not however affect odometers, tire sensors, etc. I know this for certain as I have disconnected mine a couple times and I still have trip B set from when I reset at the beginning of the year (accurate total annual mileage) and trip A for my actual mileage/tank.

You don't even loose that. You loose nothing by unhooking the battery. It will reset any codes, but they'll be in history.
No user settings, radio setting or anything is lost by disconnecting the battery.

Just do it and don't risk a fire or arcing by working with hot terminals.

 

[timoshev]

Provided you're not operating any 12V stuff with the main battery disconnected, use any 12V battery of any size with alligator clip leads. They used to sell a cigarette lighter plug set up for connection to an electronic-sized 12V battery. Same logic.