We've had a 2013 C-max for quite a few years now and I've had this problem multiple times. After extensive monitoring, I've come to the conclusion that if they sit long enough, or you take too many very short trips, the charge level in the 12v battery will drop below the minimum required to "start" the car. When I say start the car, it means enough voltage from the 12v battery to trip the relay that activates the 300v system. I keep one of those voltage meters plugged into the cigarette lighter port on the console. This allows me to see the charge level of the 12v battery whenever I enter the car. If I see that voltage down below 11.7, I hook it up to a charger for a few hours. We also tend to use it for very short trips (< 5 miles total). That makes it very hard to keep the 12v battery charged adequately.
I want to thank you so much for this video! You saved me a call to AAA and our Ford dealer about the 2018 C-Max. I borrowed my neighbor’s battery charger and after using the key and popping the hood, I followed your instructions and abracadabra it worked!!!!!!!! Thank you over and over again!!!!!
Easy to jump start it. There’s a connecting post and red cap under the hood to connect jumper cables to. Then pop the trunk and replace the 12v battery. It’s in the owners manual. My Energi needed a 12v only a few months after purchase since it sat on the lot for 9 months. If it sits for more than a week in the cold it may need a jump even with a good battery. It’s kind of small and doesn’t hold much of a charge. Add in cold weather and sitting… bad mix. Plus these cars draw a lot of current when sitting too. Annoying. But still good cars. 106K miles in just 3 years on mine. Best car we’ve owned. Again, replace the 12v battery. The car doesn’t start the engine with it. It only powers the computers. And with it being at 4v… that’s a bad 12v.
You are spot on. We ended up taking it to Ford so they could check it over as it's under warranty. They said the same thing basically. It was sitting for about 2 weeks not being driven in the cold. Battery didn't have enough amps to even start the computer. Lesson learned. Bought a USB jump starter I keep in there now. Just incase... Thanks for watching!
Sure, it will start, because the 12V only boots the computer, which closes the relays to the HV battery pack, the HV to low voltage DC converter then powers the rest of the accessories. The computer then commands the motor generator in the transmission to spin the crankshaft to start the engine, which it can do since that is powered by the separate HV battery pack.
You just need a new 12 volt battery. Every system in this great SUV goes wacky if your 12 volt battery goes bad. Battery and install less than $100.00 Enjoy the 41 miles per gallon and the best car in their lineup. I sure love mine. Mines a 2013. Gas, Oil, Tires and 2 batteries total in 8 years.
My 12V lasted 7 years but yes, when it goes it goes. About $180 at the dealer shop to replace. The battery is actually in the trunk and I paid it since I didn't want to be wrenching in 20F weather outside for a half hour.
12v volt battery in rear is only used to power computers and close a relay to connect the hybrid battery. The hybrid battery starts the engine not the regular 12v battery. It takes very little power to close the relay. The computer ensures the hybrid battery keeps enough power to start the engine. The 12v battery can pass a test and still be bad and lose power easily I've found. So just replace the 12v battery.
The 12v battery is only used to boot the computer and open relays to the high power battery, so it doesn’t get the high discharge and recharge the same battery would see in a traditional ICE. This eventuality causes sulfate to build up on the lead plates and the battery no longer delivers the proper voltage. You probably need a new battery but buy desulfating battery charger and see if it improves. I hook mine up every month or two and set the desulfation overnight. I wonder if there is a Li-ion equivalent for the 12v, battery group 67r
I plugged up my to the battery in the trunk not the front and my car started up. Mines a 2015. I won’t plug it to that battery. Can’t you mess that up if you charge that one and not the trunk battery. This confused me.
Hi Shane. My suggestion is to contact your local Ford dealer and have them check it out. There is a lot of technology in those and they have a wide range of tests they do.
Got a 2013 Ford C max hybrid. Was running very good one day and died while on the highway. Put a new fuel pump and more gas, now its still not starting. Any help would be appreciated
12 volt bat does not turn the car over, the hybrid bat does.. what kind of bat.. only replace with bat designed for it and jumping should be low amps like 10.. basically with a dead 12 volt bat you need it to close the contacts to start the car. you should just sell me the car lol
Help! 2013 C-Max hybrid. Never had a problem, now in an apartment and sub zero for 10 days here in Kansas City. Anyway. I've gone out to run for groceries and no problem. Wanted to go out Tuesday and dead as a doornail key wouldn't unlock door either. Roadside Service came with a little battery charger and started right up, like yours did. I drove it around to charge, then sat for bit, total 40 minutes. Shut off, quick grocery run then started fi e to go home. That was Tuesday. Today, Thursday, I went out and exactly the same dead as a doornail. You said in the video you were going to contact Ford. And good information? Did you end up replacing the battery you jumped? How would I know if it needs replaced or just a much longer drive? How do I know it's not the massive under floor battery that needs replaced? Bought used in 2020, 96,000 miles now. It sits days and sometimes a week or so without driving. Thanks so much for your video and any advice you can give!!
We've had a 2013 C-max for quite a few years now and I've had this problem multiple times. After extensive monitoring, I've come to the conclusion that if they sit long enough, or you take too many very short trips, the charge level in the 12v battery will drop below the minimum required to "start" the car. When I say start the car, it means enough voltage from the 12v battery to trip the relay that activates the 300v system. I keep one of those voltage meters plugged into the cigarette lighter port on the console. This allows me to see the charge level of the 12v battery whenever I enter the car. If I see that voltage down below 11.7, I hook it up to a charger for a few hours. We also tend to use it for very short trips (< 5 miles total). That makes it very hard to keep the 12v battery charged adequately.
That's a great idea. I may get one of those meters for winter when we don't drive it daily like we do now. Thanks for watching and comment.
I want to thank you so much for this video! You saved me a call to AAA and our Ford dealer about the 2018 C-Max. I borrowed my neighbor’s battery charger and after using the key and popping the hood, I followed your instructions and abracadabra it worked!!!!!!!! Thank you over and over again!!!!!
Fantastic!! Glad it worked!
Easy to jump start it. There’s a connecting post and red cap under the hood to connect jumper cables to. Then pop the trunk and replace the 12v battery. It’s in the owners manual. My Energi needed a 12v only a few months after purchase since it sat on the lot for 9 months.
If it sits for more than a week in the cold it may need a jump even with a good battery. It’s kind of small and doesn’t hold much of a charge. Add in cold weather and sitting… bad mix. Plus these cars draw a lot of current when sitting too. Annoying. But still good cars. 106K miles in just 3 years on mine. Best car we’ve owned.
Again, replace the 12v battery. The car doesn’t start the engine with it. It only powers the computers. And with it being at 4v… that’s a bad 12v.
You are spot on. We ended up taking it to Ford so they could check it over as it's under warranty. They said the same thing basically. It was sitting for about 2 weeks not being driven in the cold. Battery didn't have enough amps to even start the computer. Lesson learned. Bought a USB jump starter I keep in there now. Just incase... Thanks for watching!
Sure, it will start, because the 12V only boots the computer, which closes the relays to the HV battery pack, the HV to low voltage DC converter then powers the rest of the accessories. The computer then commands the motor generator in the transmission to spin the crankshaft to start the engine, which it can do since that is powered by the separate HV battery pack.
You just need a new 12 volt battery. Every system in this great SUV goes wacky if your 12 volt battery goes bad. Battery and install less than $100.00 Enjoy the 41 miles per gallon and the best car in their lineup. I sure love mine. Mines a 2013. Gas, Oil, Tires and 2 batteries total in 8 years.
Thank you for watching and commenting! Great vehicle indeed.
I have a question for you .. I’m having some issues with my 2015 c-max
My 12V lasted 7 years but yes, when it goes it goes. About $180 at the dealer shop to replace. The battery is actually in the trunk and I paid it since I didn't want to be wrenching in 20F weather outside for a half hour.
12v volt battery in rear is only used to power computers and close a relay to connect the hybrid battery. The hybrid battery starts the engine not the regular 12v battery. It takes very little power to close the relay. The computer ensures the hybrid battery keeps enough power to start the engine. The 12v battery can pass a test and still be bad and lose power easily I've found. So just replace the 12v battery.
Excellent advice. Thank you for watching and commenting.
The 12v battery is only used to boot the computer and open relays to the high power battery, so it doesn’t get the high discharge and recharge the same battery would see in a traditional ICE. This eventuality causes sulfate to build up on the lead plates and the battery no longer delivers the proper voltage. You probably need a new battery but buy desulfating battery charger and see if it improves. I hook mine up every month or two and set the desulfation overnight. I wonder if there is a Li-ion equivalent for the 12v, battery group 67r
I plugged up my to the battery in the trunk not the front and my car started up. Mines a 2015. I won’t plug it to that battery. Can’t you mess that up if you charge that one and not the trunk battery. This confused me.
I believe the battery is actually in the trunk but Ford provides a terminal in the front to use to jump or charge the starting battery.
I know you will get it figured out but at least you have the van and truck as backup.
Always good to have a backup vehicle. Thanks for watching!
Hey-still having the problem? I’d love to chat. I have a 2013 with very random battery/power issues.
Hi Shane. My suggestion is to contact your local Ford dealer and have them check it out. There is a lot of technology in those and they have a wide range of tests they do.
Thank you for posting this video
Thank you for watching
Got a 2013 Ford C max hybrid. Was running very good one day and died while on the highway. Put a new fuel pump and more gas, now its still not starting. Any help would be appreciated
Reach out to this guy www.youtube.com/@ElectricalCarRepairLIVE/search?query=%20c-max
Catching up commenting Fred.. If it's not one thing, it's another. Always something...
I'm catching up on comments as well LOL
I HATE SNOW
needed some attention and fixed.
For sure. Calling Ford tomorrow. Computer turning off for some reason. Too many computers in these cars these days.
What was it?
Dead 12vdc lead acid battery is the weak link.
12 volt bat does not turn the car over, the hybrid bat does.. what kind of bat.. only replace with bat designed for it and jumping should be low amps like 10.. basically with a dead 12 volt bat you need it to close the contacts to start the car. you should just sell me the car lol
We didn't let it sit sit for any extended period of time this winter so didn't have that issue. Lesson learned.
Help! 2013 C-Max hybrid. Never had a problem, now in an apartment and sub zero for 10 days here in Kansas City. Anyway. I've gone out to run for groceries and no problem. Wanted to go out Tuesday and dead as a doornail key wouldn't unlock door either. Roadside Service came with a little battery charger and started right up, like yours did. I drove it around to charge, then sat for bit, total 40 minutes. Shut off, quick grocery run then started fi e to go home. That was Tuesday. Today, Thursday, I went out and exactly the same dead as a doornail.
You said in the video you were going to contact Ford. And good information? Did you end up replacing the battery you jumped? How would I know if it needs replaced or just a much longer drive? How do I know it's not the massive under floor battery that needs replaced? Bought used in 2020, 96,000 miles now. It sits days and sometimes a week or so without driving. Thanks so much for your video and any advice you can give!!