How do you jump start a car WITH your CMAX?

[WannaCMAX]

I read there are terminals in the engine bay.  Is it pos to pos, neg to neg,... or neg to chassis x 2.

 

Any chance of damaging?  

[plus 3 golfer]

Just like a normal car.  (+ to +) and ( - to - ) or ( - to chassis ground).  Use the positive post (red cap on it)  and negative post (no cap) located under the hood OR in the lift back area under the right cover on the floor, use the exposed positive terminal of the battery and the chassis ground stud to the left of the battery with black wires to it. The negative terminal of the battery is not exposed.

Edited March 26, 2020 by Plus 3 Golfer

[harmanrk]

I'd throw out there, don't.  Booster packs are cheap these days, and designed for the task, and if something goes wrong, you're only out 20-50 bucks, compares to the potential damage to the on board computer on your car.

[joe]

I have used one of those lithium battery packs on my C-Max several times.  Your manual will show you where to attach the cables in the engine compartment.  Remember, the 12 volt battery doesn't start the engine, it closes the electric relays and starts up the computers.  So it doesn't take that much power to start things.  And it is so much easier hooking up in the engine compartment rather than trying to connect directly to the battery in the back.

[raadsel]

As Plus Three Golfer stated, under the hood using the terminals, and possibly the frame for the negative. The other thing is you need to make sure the engine is running, so you'll likely need to push the gas pedal all the way down to keep get (and keep) the engine running.

[plus 3 golfer]

I misread the first post as I thought you wanted to jump the C-Max.  You want to jump start another car with the C-Max.  See my post below.  The C-Max battery IIRC is rated at 390 CC Amps. The DCDC converter puts out a max of 145 Amps.  I wouldn’t want to crank another car with a dead battery for very long with the C-Max unless it were an emergency.  I think the risk is blowing the a fuse.

 

 

Edited April 1, 2020 by Plus 3 Golfer

[notquitesane]

I only boosted one person so far.  It was a British guy in a campground with a late 70's Ford Econoline based motorhome.  He was surprised to see a C-MAX in Canada and was confused why it wasn't making noise when I pulled up.  He waited for almost an hour for the campground to send someone boost him.  It was almost checkout time and he saw me and asked for some help.  My booster pack was dead at the time and I always carry booster cables in the back of my car, so I gave it a go.  Used the terminals under the hood.  Got him going pretty quick.  The gan engine kicked in when we hooked up the cables.  I know everything is pretty electronic in the cars now but I turned everything off except the HVAC blower fan.  So yes it can be done with the terminals under the hood.  It's not something I do often, but this guy was in need.

[METROVAN3]

If you must, Only jump start with the car off. If you Give someone a boost with the car running, You will end up damaging your computer. Like it was already posted, Invest in a Power pack. 

If you need to disconnect the battery, Use a Memory Data Saver ( https://www.amazon.com/gp/product/B07DNC4B11/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1). This tool with save you from having to reset the electronics in your car.

[fbov]

2 hours ago, METROVAN3 said:

If you must, Only jump start with the car off. If you Give someone a boost with the car running, You will end up damaging your computer. ...

Hmm, owner's manual disagrees.....

"Jump Starting

1. Start the engine of the booster vehicle and run the engine at a moderately increased speed.
2. Start the engine of the disabled vehicle.
3. Once the disabled vehicle has been started, run both engines for an additional three minutes before disconnecting the jumper cables."

 

OTOH, I've never done the 30-minute thing. 

 

Stay well,

Frank

[plus 3 golfer]

The C-Max 12 V battery is charged by the HVB via the DCDC converter.  So, if one is going to jump start another vehicle with the C-Max, the C-Max simply has to be in the ready to drive mode (engine doesn't need to be running) .  If the HVB is depleted to the “ICE on” threshold, ICE will start and run appropriately to charge HVB.  As I've said prior, I really don't see an issue with damaging any C-Max modules whether the ICE is running or not but I won't do it (especially in very cold weather) as I see a chance of blowing the DCDC converter 12 V fuse.  Also,  the negative post under hood is chassis ground.  The jumped battery will look like a load since the current supplied by the converter to the other vehicle does not flow through the ground wire of the C-Max battery. Thus,  the converter will hold set point voltage (as determined by the PCM) based on the BMS of the C-Max .  Charging the C-max  battery for 3 or 30 minutes after jumping another vehicle will add little charge to the C-Max battery.

 

Also, modules have transient protection built into them (assume Ford follows standards) including reverse polarity, jump start, load dump, cranking, and so forth based on ISO and other standards. Of course, one could perhaps exceed the protection capability.  For example, a quick search shows that a standard over voltage protection is 42 V (assume transient like load dump) and 24 V for 4.3 seconds.  For example, what would happen if I were to use one of my 12 V golf cart batteries to jump my C-Max and mistakenly jumped it across 2, 3, or 4 of the golf cart batteries in series. ??  

Edited April 12, 2020 by Plus 3 Golfer