Battery; 2016 C-Max Hybrid

[plus 3 golfer]

For clarity; there are 2 batteries in the C-max; one small one that is used exclusively to Start the car the other larger is the HVB that runs the AC, Power Steering, EV, etc....all Electrical components.  This is just a Hypothetical, If by chance, the Hybryd battery were to go completely dead, would the "Starter" battery start the car and the C-Max would run on the Gas engine.....?

 

Clarity; the battery display....very bottom its showing 32% charge, very top 65% charge?

If you look at the chart I posted derived from actual data, 1) when the battery symbol is full to the top, the HVB is at least at 65% SOC but the actual SOC could be higher as it is on the chart and 2) when the battery symbol shows empty, the HVB is no more than 27% SOC (extended dotted line on the graph) but perhaps it could go lower but no one has reported seeing actual SOC any lower than 27%.

[Telerisk]

Thanks; am I correct, should the HVB die.....the 12v battery would start the C-Max...and the vehicle will run on the Gas engine.....one Poster wrote, if the HVB Battery dies, Vehicle will not run......reason for asking.  It wouldn't seem logical that with a Dead HVB battery that the Gas engine would not operate the C-Max.

 

I may sit down with the dealership Service Mgr and have a talk....at one point he mentioned bringing in the vehicle and leaving it with him for a "Few" days.  I just don't feel it should take a 'few" days to determine if there is an issue with the HVB Battery.  I don't feel its the charging because if that were so...I would think the increase in Charge as displayed by the Symbol would be slow to take place, its not so, it is just the discharge running on EV where the symbol drops more quickly then it did in the past.  

[Bill-N]

The internal combustion engine (ICE) is started by one of the High Voltage electric motors.

[plus 3 golfer]

Thanks; am I correct, should the HVB die.....the 12v battery would start the C-Max...and the vehicle will run on the Gas engine.....one Poster wrote, if the HVB Battery dies, Vehicle will not run......reason for asking.  It wouldn't seem logical that with a Dead HVB battery that the Gas engine would not operate the C-Max.

 

I may sit down with the dealership Service Mgr and have a talk....at one point he mentioned bringing in the vehicle and leaving it with him for a "Few" days.  I just don't feel it should take a 'few" days to determine if there is an issue with the HVB Battery.  I don't feel its the charging because if that were so...I would think the increase in Charge as displayed by the Symbol would be slow to take place, its not so, it is just the discharge running on EV where the symbol drops more quickly then it did in the past. 

ptjones and  Bill-N have already answered your question above in red but let me expand the short answer of "no".

 

When you attempt to start the car and prior to "ready to drive", the 12V battery must be "good" to enable power up of the control modules.  After power up, the status / functionality of all critical control systems / devices is checked by the module software.  If a critucal fault is found (like dead HVB), the startup process stops.  If no faults, the starup process continues and the ready to drive message is displayed.  If you want to start ICE after the message, push and hold the accelerator pedal to the floor and ICE will be spun by the electric motor referred to as the generator or MG1 with power from the HVB.

[jestevens]

Aren't there some SOC parameters they can look at in IDS?  If you guys can get all of this data via phone app then maybe it's just a question of the shop being too busy to actually spend time with the car.

[Telerisk]

I must be honest; when I took the C-max in with the complaint, I really did get the feeling it was a drive it, see it....I just didn't get the feeling the issue was thoroughly checked out....the display showed a charge, no matter it was low, it passed as OK.

[Telerisk]

Update...Now that Winter is here in Tampa, Fl, Temps in the 70's...."pause for effect for those of you living in the North...." and I am not using the AC; my HVB symbol averages at midpoint or higher....the different, have not had to use AC.  I realize AC is totally driven by Battery Power....so now it makes me wonder why in my 3rd summer of ownership why this past summer the HVB averaged midpoint to bottom, vs the pror 2 summers when it averaged Midpoint and higher....could the AC Electric Motor be drawing more battery Power then previous summers?  AC Compressor with age requiring more Elec Power to run?    I will write, the AC in my C-Max is by Far the Best AC I have ever had in any vehicle, it blows Cold very fast and the volume of Air is terrific cooling my hot vehicle quickly.  So I Point out the questions above as a could it be....with the follow that the AC Runs great.

 

It is just that the only difference between now and this summer...is now I am not running the AC......

[plus 3 golfer]

I must be honest; when I took the C-max in with the complaint, I really did get the feeling it was a drive it, see it....I just didn't get the feeling the issue was thoroughly checked out....the display showed a charge, no matter it was low, it passed as OK.

 

Update...Now that Winter is here in Tampa, Fl, Temps in the 70's...."pause for effect for those of you living in the North...." and I am not using the AC; my HVB symbol averages at midpoint or higher....the different, have not had to use AC.  I realize AC is totally driven by Battery Power....so now it makes me wonder why in my 3rd summer of ownership why this past summer the HVB averaged midpoint to bottom, vs the pror 2 summers when it averaged Midpoint and higher....could the AC Electric Motor be drawing more battery Power then previous summers?  AC Compressor with age requiring more Elec Power to run?    I will write, the AC in my C-Max is by Far the Best AC I have ever had in any vehicle, it blows Cold very fast and the volume of Air is terrific cooling my hot vehicle quickly.  So I Point out the questions above as a could it be....with the follow that the AC Runs great.

 

It is just that the only difference between now and this summer...is now I am not running the AC......

If you really want to know what is happening, forget the dealer and get ForScan. See this thread.

 

You can also monitor AC compressor load, rpm and so forth. along with power to the 12 V system to see what draw is on the HVB.  The AC compressor is very efficient and the algorithm uses pulse width modulation of the high voltage to control average voltage the compressor sees. Thus, it will operate at very low power levels once the cabin is cool.

 

You can also pull up the Accessory Power display in MY VIew on the left hand display and watch what happens with the Climate load and other load (12 V load).  In the 3 Phoenix summers (100F+ and full sun), I will see 4-5 kW of climate load for perhaps several minutes before the load drops down to 3, 2, 1 kWs and settles in the 250 W to 400 W range depending on conditions.  So, if your climate load doesn't drop once the cabin is cool, something is amiss.  Next hotter day with cabin hot, turn on AC and see what happens. ;)

[Telerisk]

Well, I'm Back....  Here in Florida we went thru 3 weeks of what we consider Cold....highs low 60's so AC was not needed.  During the 3 weeks HVB was always upper half....never falling below half.  The past week it has gotten back to low 80's and AC is being used; HVB back down staying in lower half...so AC is having an Impact on HVB Charge level.  I went to MY VIEW; turned on AC and it barely shows any of the Blue bar....should I have seen while at Idle in driveway, running AC...the Blue Bar in My View at any time showing a rise?  I will write; AC in this Car is the coldest and best running AC of any car I have ever owned.   

 

From monitoring the HVB Charge level the past 4 weeks; 3 wks cold/no ac running...high Charge levels (at times almost to the Top Tip) to this last week with AC running, Low Charge levels always midland or Lower....seems it points to right or wrong, something not working right or not...the AC running vs not...makes a Big difference in the HVB Charge level of my C-Max.....

[Redshift]

Thanks; am I correct, should the HVB die.....the 12v battery would start the C-Max...and the vehicle will run on the Gas engine.....one Poster wrote, if the HVB Battery dies, Vehicle will not run......reason for asking.  It wouldn't seem logical that with a Dead HVB battery that the Gas engine would not operate the C-Max.

 

The 12v battery cannot start the C-Max because the C-Max doesn't have a starter. Totally on the HVB to start it.

[jestevens]

It sounds like normal operation to me - the AC compressor is variable speed, powered directly off the HVB similar to a Prius so in extremely hot weather it is going to draw down the battery quite a lot. Your engine should start more frequently to charge up the battery to compensate.

 

Right now I am experiencing the reverse in PA, as it is 30 degrees or below the engine runs more to generate cabin heat, the battery gets all of the energy it can handle.  The Energi has a bigger battery so they are able to use that for cabin heat but I have only the standard hybrid.  Still, the stock MPG in winter is around 31 which better than I could ever do with my HHR even on a good day.

 

The 12V battery must have enough charge to run the computers, which close the relay on the HVB battery pack and command energy to be used from the HVB to spin the generator, which spins the crankshaft, which starts the engine.  Sort of like a Model T, but a lot more complicated.  This is the best way to go if you are constantly starting and stopping the engine vs. using a traditional starter or coil pack I'd guess.

Edited January 10, 2019 by jestevens