Question on disconnecting 12v battery

You may disconnect just the positive terminal. Put it in a small plastic bag so it doesn't accidentally reconnect when you let go of it.

If you do disconnect the positive terminal, be aware, any mistake wherein you touch part of the car body with your tools will result in vigorous sparking and possible damage to the battery or the electronics. This is why it is recommended the -first- battery lead to be disconnected should always be the negative terminal. Any mistake there results in nothing happening. Once it is disconnected you can short the positive terminal to the car body without harming anything.

 

I can't remember what I did exactly, but I had the negative terminal turned around so the nut is easily accessible.

 

when you disconnect it you will lose all presets on the radio and map info. I done it a few times already.
remember to remove rings watches etc in case you touch ground..

 

My presets and map settings never reset everytime i disconnect the battery. Just the display settings.

 

I've always heard you disconnect the negative lead first, then the positive. While I don't undertand the logic, my understanding is that what your service writer advised is actually dangerous. I do know the battery's negative lead connects to the car body, that the car body acts as part of the circuit, that's about it.

BTW: how long is the storage period?

What I did when the our car was sitting for just a couple of weeks was leave the 12 volt connected and hooked up a lowish amperage "intelligent" charger.

 

Disconnecting the negative lead at the point where it connects to the body not the battery is easy and safer and as stated above put the end in a plastic bag or put some tape round it to stop it touching any bodywork.

 

I would normally agree but it states in the manual not to do this, as the lead is long enough to reach the positive terminal, which would be a bad thing, I guess.

 

Not if it's in a plastic bag.

 

Do you know if it will reset the reverse beeping in a 2012? I had the dealer disable the beeping to just one beep when in reverse. Will I have to go back to the dealer to get it changed again? Thanks

 

Yes, it will reset everything to default.

 

Does the electronic rear hatch lock still work if the 12vdc aux battery is disconnected?
If not how does one open the rear hatch door to get access to the aux battery so as to reconnect it?
Is there some manual latch or old-fashion key lock I can use?

 

No, the latch won't work. It must be released from -inside- the car.

Remove hatch floor. You will see a shiny lever (small) right under the hatch latch.
Actuate that manually to open the hatch door.

 

The neg is removed first because if the wrench your using to remove the negative terminal should touch the body by mistake there will be NO sparks as the ground lead already touches the body. But if you remove the pos first with a wrench and your wrench touches the body guess what happens.

BUT.....I do not own a III i own a II and on the II disconnecting the neg lead to isolate the battery is not necessary. There's a little cover on the pos terminal that pops right off and under that cover there are click in connectors for the pos leads. One large connector and one small. These connectors are easily clicked and removed. Battery unplugged!! No wrenching necessary. No tools needed. I bet the Gen III is just like that too.