A shunt on chassis motor?

[Naio]

Yep it's me again, with another harebrained scheme :-).

My current van doesn't have an isolator setup. For an upcoming trip, I'd like to be able to run my mini freezer while driving. I don't want to do a whole isolator solenoid deal at this time.

It seems like the simplest way might be to hook up my inverter to the chassis battery with an Anderson connector, and unplug it or shut off the inverter when stopped.

But how would I connect to the chassis battery without interfering with the starter/battery clamps? I'm too chicken to use jumper cables :-). Is there some type of shunt that does this job?

[Naio]

I actually would like advice on doing the solenoid thing myself sometime, because I thought that auto electric shop charged me a ridiculous fee. But right now I'm dealing with a lot, and I don't have time to trace wires under a dashboard.

PS I got sympathy email because of your posts to me! But I don't think you are that bad. Nothing compared to what I'm dealing with IRL, right now. I need a new line of work.

[ajriding]

If you can bolt a terminal ring to the battery then you can wire up a solenoid. Literally the only difference from an Anderson plug is you have one small wire coming from any ignition powered source (radio, blower, or switch...).
Instead of the Anderson plug you have a solenoid.
But the anderson plug will work too, same thing in the end

[Naio]

Orly? I already have some, so I think of them as free :-). But I was going to order this from genuinedealz, so maybe it would be expensive.

[LittleBill]

anderson will prolly cost you more then a solenoid to be honest.

[Naio]

I don't know if I'm cheap and dirty. I'm sick and exhausted, and I have a deadline. I'm not going to do anything that involves crawling under the van right now, if I can help it.

On a previous van, I paid an auto electric shop to do the solenoid job; it was $600. That seems like a lot for something I think I'm going to use once. I used it once on that previous van, too. That was seven years ago.

[ajriding]

you're one cheap n dirty rver to not want to bother with a solenoid which is also cheap. I think solenoid would be easier than an anderson plug.
a ring terminal on the positive off of the battery then you can ground the negative cable on the frame anywhere.
You can find 12+ going into your fuse box under the hood also, but I would be weary of pulling so many amps through the wires that provide power to run the vehicle too.

Adding a lot of connections at the battery is not good for the reason that there can be so much corrosion at the battery due to gasses from the battery. Many modern vehicles will have one connection that goes a few inches away and then everything gets attached there just to avoid some possible corrosion issues down the road.

You can also get your 12+ off of the starter motor under the vehicle. There is a very heavy gauge wire leading to that and it is only used for starting the motor, never during the drive, so is available to power your inverter during the drive. This gets closer, possibly, to where your inverter will be and gets you away from another battery connection at the battery. Electrically there is no difference, but requires more care running wires under the vehicle.
Be careful, the starter power feed wire is hot all the time.
Disconnect battery to do work if you want to be safest. Stray electrical surges, from the sparks you might get touching 12+ to ground, could damage electronics - though rare, "could".

As far as plugging and unplugging an Anderson plug, no issues there, again, electrically it is the same as an "on" solenoid. Turn the inverter on after you plug in, off before you unplug.

[opnspaces]

Yes, you can pull the nut off the battery clamp and put the ring terminal on the bolt. You can try not to twist the cable clamp while working. But in reality it should be fine if you tighten it down. And definitely make sure you add a fuse by the battery.

[theoldwizard1]

Naio wrote:
Do I put the ring terminals on the bolt that goes through the battery clamp cable clamp?

Yes, that would be acceptable.

Naio wrote:
I do have short, heavy gauge cables for the inverter, with ring terminals on one end and Anderson on the other.

You really want a fuse in the short cable.

Depending on the size of the inverter, you can buy a 10 gauge in-line fuse holder cheap on eBay and splice it in.

[Naio]

Do I put the ring terminals on the bolt that goes through the battery clamp cable clamp?

I do have short, heavy gauge cables for the inverter, with ring terminals on one end and Anderson on the other.

[pianotuna]

Naio,

Buy some ring terminals for the battery. Do put a fuse or circuit breaker on the positive near the battery. You may wish to use ring terminals at the inverter, too.

[ScottG]

A shunt is not the device you're looking for.
But the only way I know to do it is the right way, with heavy cables directly to the battery.