Possible 12volt Dead Battery Solution

[ptjones]

Have you taken your CMAX to FORD Dealer yet? :)

 

Paul

[ptjones]

It sure would be nice if someone try out this potential solution to see if would solve the problem. Preferably someone that is having Dead Battery often so we would get results soon. IMHO :) 

 

Paul 

[homestead]

Last year after reading about some of the cmax's with the dreaded dead battery problem I came up with a similiar idea to Paul's

to implement if my cmax ever exhibited that problem.  The idea was to get a smaller 12V battery small enough to fit in the

little storage compartment above the original 12v battery.  Then wire the batteries in parallel except with a series diode in the positive

wire to the secondary battery.  This diode would allow the secondary to charge when the car was running but would prevent the

secondary battery from discharging.  There would also be a switch which could short out the diode so that in the event the main

battery was discharged you could "jump" the main battery and get going again.

Never had to test this out since my car has never had a battery problem in the year and half I have owned it.

Having a external battery jump box would do the same function but with my idea but you would only have to flip the switch

to get going again and it would be out of sight.

[bgarr]

I  just sent our 2014 CMAX to the dealer on a ramp truck.  Our battery died for the third time in the two months since we bought it.  The first time, I jumped it with a big sealed lead-acid jumper battery that we had on hand.  The second time, I used one of those cute little jumper/usb/flashlight things from amazon.  Started right up both times.  Today, the little glove box jumper would get the engine started but the engine would die again as soon as I removed the jumper.  The voltmeter I have in the power point socket showed that the battery was not charging when the engine was running.   I don't have a regular battery charger or I would have taken the battery out to charge it.

 

I thought I had things covered when I put the little jumper pack in the glove box.  Guess not.

 

BTW, I would not fool around with connecting or disconnecting the battery with the car running.  I think that kind of thing could cause destructive electrical transients.  This car is vastly complicated and I'm not sure it is well protected from unusual electrical conditions.

[jdbob]

The voltmeter I have in the power point socket showed that the battery was not charging when the engine was running. 

 

Sounds like the DC/DC converter that is supposed to charge the 12V battery from the High Voltage Battery might be broken. As soon as you got the car into "Ready to Run" mode it should have started charging the 12V battery, regardless of whether the engine was running or not.

[bgarr]

Sounds like the DC/DC converter that is supposed to charge the 12V battery from the High Voltage Battery might be broken. As soon as you got the car into "Ready to Run" mode it should have started charging the 12V battery, regardless of whether the engine was running or not.

I think the voltage showing was just the jumper voltage.  The battery was dead as a doornail. 

 

Car: CMAX SE, only option is winter package.

1600 miles

purchased in September 2014, Built in April 2014.

 

Conditions that might pertain:

Driven on wet roads before being parked in the garage.

Remote locked twice so the horn beeped.

Gas tank 3/4 full.

Synced to an iPhone for the first time.

[ptjones]

I was away for a week with MADMAX in the garage and when I opened the door voltage meter was reading 11.7volts. HVB SOC was approx. 3/4 and everything worked fine. :)

 

Paul