Install a Battery Voltage Meter - Must have

[SPL Tech]

Which fuse did you replace?

[Keith Higgins]

In addition to the voltmeter you need to carry a jump starter for you CMax. Several times I've had to jump start my 2013 because the 12V battery died while the car was sitting in the garage and I had driven the car the previous day. The dealership told me in town only driving will not sufficiently keep the battery charged and I need to get it out on the highway now and then. That's a big unknown because how do you know if the alternator is charging the battery and at what speed. Yes, they need an altimeter and a voltmeter on the dashboard to let you know if your 12V battery is charging, is being charged or is charged!!!

[homestead]

My daughter's c-max had a dead battery because she accidentally turned on the lights with her knee when she got out of the car.

She had a portable jump pak and was able to start the car and drive it a couple days and then had to jump it again.

Also the radio stopped working.

I put my charger on the 12v battery and fully charged it.  No more issues and the radio is woking again.

Her short trips just weren't charging the battery enough.

 

On a side note when I got out of my Mach-E a couple days ago my knee kit the light switch and turned the lights on.

The car started dinging and alerted me to the lights being on.

So I can see how that can happen.

[cr08]

22 hours ago, Keith Higgins said:

In addition to the voltmeter you need to carry a jump starter for you CMax. Several times I've had to jump start my 2013 because the 12V battery died while the car was sitting in the garage and I had driven the car the previous day. The dealership told me in town only driving will not sufficiently keep the battery charged and I need to get it out on the highway now and then. That's a big unknown because how do you know if the alternator is charging the battery and at what speed. Yes, they need an altimeter and a voltmeter on the dashboard to let you know if your 12V battery is charging, is being charged or is charged!!!

 

Just some clarifications: No alternator on these vehicles. They have a DC-DC converter that takes its place and converts power from the HVB/traction battery at it's nominal ~300V or so and converts it down to the 12+V for the 12V components in the vehicle and to charge the 12V battery. It's programmed to mimic an alternator as far as voltage levels and charge/discharge behavior. One thing to note, and was kinda covered way back in the day here in this thread: Upon 'waking' the car like unlocking, opening a door, etc. the DC-DC converter will go into a kind of baseline operating mode that it puts out a low 12-13V level of charge. Once the vehicle is fully started, it jumps to the normal 14+V and goes into full operation.

 

The DC-DC converter also runs full time when the car is fully started and the ICE or road speed has zero impact on that. It continues to run while the ICE is off as well. This is for the hybrid of Energi model. No difference.

 

For a 2013 if you're still having issues I'd certainly check with a dealer to make sure any outstanding software updates and TSBs are sorted regarding power draw or charging issues. There were quite a number for the early model years that were put out way back in the day. Getting the ACM updated as well is also a good idea as that's another common culprit concerning the radio not being operational or getting stuck on at key off which can also cause a battery drain. That's also been fixed with a simple software update the dealer can do.

 

That all said, a jump starter is definitely not a bad idea to have around just as insurance. The small lithium based packs are fantastic for their size as well as being able to use most of them as a USB battery bank. And our cars don't need much out of them. It can also come in handy for jumping other vehicles as needed as it's not recommended to do so directly from our vehicles (The DC-DC converter is not a cheap replacement if it fails which the bursty jump starting load can potentially cause. Other manufacturers including Toyota already call this out for their hybrid vehicles and recommend against it).

 

As an anecdote, I do have a 2013 Energi SEL myself and it had the factory 12V battery when it finally died and got replaced Dec 2021. It's been perfect so far.

 

In my educated opinion on it, I think a lot of it comes down to software updates not getting done especially this late in the vehicle's lifetime. Unfortunately the important ones require specifically going to your dealer, having them do the diagnostic work, and hope their techs know what they're doing and trace it back to TSBs that call for the updates. It's all a chain of hoping every step goes the way you want it to go and sometimes it doesn't even get started because people are either wary of going to dealers or mechanics in general or are stuck in old, analog mindsets and don't realize these things are chock full of various computer modules which can and do get fixes and improvements over time. The ACM issue is a VERY good example of this. Most live with it and do the classic fuse pull which is just a bandaid but Ford has had a permanent fix out there in software for a while.

Edited May 9 by cr08

[Bill-N]

For those who may be unaware, the rear hatch cannot be opened if the 12v battery is dead, so do NOT keep jumper cables in the rear cubby.

[cr08]

18 minutes ago, Bill-N said:

For those who may be unaware, the rear hatch cannot be opened if the 12v battery is dead, so do NOT keep jumper cables in the rear cubby.

Absolutely! I keep mine in the storage cubby in the back seat on the passenger side just for this reason. The small pack I have even with the jumper leads and the 120V charging cord fit just fine in there.