12 v battery charging

[Jack Schmidling]

I have had a 2014 Cmax for about two week and yesterday the battery was dead and had it jumped and then got into this battery mess.

 

  We typically use the car only to go shopping once a week with an occasional run in between.  Was buying this car a bad idea?

 

My real question is based on the words of the guy who came out to jump it.  Something like, let it run for 45 minutes before driving or turning it off.  Sounded reasonable.

 

After about 15 minutes I went out to find nothing running but blowers for the heater it seems obvious that this is no way to charge a battery.

 

Which one of us is wrong?

 

He also said  not to connect a 12 v charger to terminals under the hood but to go directly to the battery in the trunk.  This seems grossly inconvenient and his reason didn't make much sense because he didn't do a very good job of explaining why.

 

It also occurred to me that I might charge it through the 12 v lighter jack in the cab.but I measured 0 volts when I went out to check it with a DVM.

 

Nuff for now.  Any help?

 

js

 

 

[obob]

Welcome Jack.

 

Talk about a loaded question.

 

You may need a new battery. ( people with 2013s have started to replace them)

 

You may need a software update.  ( Go to www.etis.ford.com , click on vehicle, enter VIN and see if you need an upate   This is unlikely because most cars were done a year or two ago to fix a battery discharge problem. )

 

The gas engine only runs when it needs to.  If you want to run the engine one way to do it is turn the heater on with a high temperature setting and fan on high with windows open and foot and middle flow set.  The engine will need to run to keep it hot to work the heater.

 

This car uses the 12V battery to power the electronics.  The car is started with the High Voltage Battery (HVB) and an electric motor in the transmission.

 

I keep something like this in the car to avoid having to get a jump from the jumper guy.  https://www.amazon.com/Beatit-18000mAh-Portable-Starter-Charging/dp/B01MY9FZM4/ref=sr_1_6?ie=UTF8&qid=1515257584&sr=8-6&keywords=battery+jumper

It does not need to be attached to the battery directly - can use the terminals under the hood.  It is small.

 

I am not sure about what happens if a car sets for a week but if I wanted to find out I would buy one of these and check the voltage each day or so:  https://www.ebay.com/itm/Digital-LED-Auto-Car-Cigarette-Lighter-Volt-Voltage-Gauge-Meter-Monitor-12V-24V/182161792450?hash=item2a69b05dc2:g:8KIAAOSwvg9XVg24&vxp=mtr 

I find it hard to believe it is normal for a ggod battery to be down after a week.

 

I am interested in what you find out.

Edited January 6, 2018 by obob

[Bill-N]

What obob says is spot on.

 

Get a 12v "cigar lighter" voltmeter to monitor the battery.  Note, the two 12v outlets in front power off a few minutes after the car is turned off, and come back on when the door is opened.   Use the under-hood connections to jump the car (as designed).

 

IMHO, buying the car was not a bad idea. :)

 

 

Cheers.

[raadsel]

The guy who jumped your car has no clue what he is talking about. First, use the leads under the hood to jump the car -- there is no reason to do it directly from the battery. Second, the 12V battery is not directly charged by the engine (as I understand the system), it is instead charged by the Hybrid battery. As such, there is no reason to keep the engine running for 45 minutes. Instead, the 12V battery can charge quickly and, if the HVB needs to be recharged then the engine will turn on until it is charged enough.

 

The C-Max is a great little car, it was not a mistake to purchase it. However, it does help to learn the basics of how the hybrid system works and how to drive it. For example, another difference is that when "starting" the car the 12V battery only starts the electronics and makes the car "ready to drive" (green light by the speedometer that says the car is on). If the car needs to start the engine, it is started by the Hybrid battery.

 

I'd get your 12V battery tested to see if it needs to be replaced -- the battery is getting old in a 2013 car; then again, it could just be the cold weather that caused the battery to have issues this week. I'd also, as suggested, ensure that any Field Service Actions for your car have been performed.

[Jack Schmidling]

Are you confirming the fact that it is OK to connect a typical 12 v 6a auto battery charger to the terminals

under  the hood that are used for jumping?

 

If so, it hardly seems worth investing in the jumping gizzmo.

 

js

[Jack Schmidling]

Lots of good stuff here.  I just purchased the jumping gizzmo suggested but prefer to shop on Ebay and it was the same price including

shipping.

 

So now I feel comfortable during my learning experience.

 

The user manual raises more questions than it answers which is why I joined this list.

 

I suspected that there could be some way the HVB was involved in the starting but nothing like this is obvious from the manual.

 

I am a child of the 50's and really got into the Mobile Economy Runs and have good a feel for the issues of MPG and enjoy working

with the instrumentation provided.  On my second run, I got 57 mpg on a 15 mile trip while my wife got only 32 getting there.  I now realize

that there are considerations at the beginning because of cold weather and getting the car warm so it was not a fair comparison.

 

After the dead battery problem, I am wondering if the price for good mileage is a dead 12v battery.

 

Another obvious question.... . what is the voltage of the HV Battery and why is this not in the manual?

 

What and when actually charges the 12V battery?

 

js

[cr08]

Reason the HVB voltage is not in the manual is there is really no reason to need to know it. It'll vary depending on state of charge and will discharge further than a normal 12V battery will. And under 99.9999% of conditions it will never go dead. Lots of safeguards against this. To the point that there are currently no known dead HVB issues that I am aware of published or documented going waaaaay back to 2008-2010 with the second gen Escape hybrids and early Fusion hybrids. But FYI, the nominal voltage of the HVB is around 300-310v.

 

The only thing the 12V battery does is get the computers up and running in the car. While the entire car is off, the HVB is completely disconnected and will have no drains on it. Starting up, it reconnects the HVB and gets everything going and the DC-DC converter begins supplying 12V power to the car just like an alternator, regardless if the ICE is running. When the ICE needs to start, the HVB does the cranking using the internal starter-generator motor in the transmission.

Edited January 7, 2018 by cr08

[Jack Schmidling]

If the HVB never goes dead and there is a DC-DC converter that presumably charges the 12v and the 12 volt

is only used for electronics, why would there not be enough power in the 12v to get things going? i.e., what battery

is dead when the car wouldn't start? Why can't everything run off the 300V battery and down converter as needed?

 

 

And how much current does it take to jump start the car? Sounds like a few amps only and kingdom that was lost for

the loss of a horse shoe nail.

 

js

[cr08]

The 12v battery and systems is like any other car. There can be drains while the car is off that can drain it low enough where it wont be able to power the various computers reliably. Age and cold weather can also effect that and rate of 'offline' discharge just like any other car. Reason why the HVB doesn't run more stuff is it would cost a LOT more to develop the various electronics to run off it. 12V systems are so ubiquitous it is much cheaper and less hassle to build it this way. Every hybrid/plugin/EV runs this way even Teslas.

 

Honestly don't know what the starting amperage is but it is definitely less than a tradiitonal ICE vehicle without the engine cranking load to worry about.

 

It is a little bit of a pain and in a way I do wish there was some sort of built in jump starter utilizing the HVB. I have one of the Energi models with a larger battery and it is basically the same. Even with a full HVB charge if the 12V battery is dead, the car isn't going anywhere. Once the car is jump started that whole HVB becomes available.

Edited January 7, 2018 by cr08

[raadsel]

If the HVB never goes dead and there is a DC-DC converter that presumably charges the 12v and the 12 volt

is only used for electronics, why would there not be enough power in the 12v to get things going? i.e., what battery

is dead when the car wouldn't start? Why can't everything run off the 300V battery and down converter as needed?

 

 

And how much current does it take to jump start the car? Sounds like a few amps only and kingdom that was lost for

the loss of a horse shoe nail.

 

js

 

When the car is turned off, the Hybrid Vehicle Battery (HVB) is electronically disconnected. The primary reason for disconnecting the HVB is safety, particularly to help protect those working on the car (including first responders in case of an accident). Also, you would not want the HVB fully discharging as it then would be very difficult to recharge -- since there is no easy way to connect it to another power source and it cannot start the engine, which is the normal method to charge it.

 

When you "start" the C-Max, the 12V battery starts the "computers" (processor chips) in the C-Max (I believe there are about 3?) and the HVB gets reconnected. Once started, the 12V battery powers most electronics in the car (radio, dashboard displays, climate control fans, etc). The one exception would be the Air Conditioning, which (at least from what I recall) is powered by the HVB. The HVB, other than the A/C, powers the electric motors (and is charged by them) and charges the 12V battery. The computers determine when to have the HVB/electric motor start the engine; this is based on a number of factors including the engine and fluid temperatures, the charge state of the HVB, and the climate control heater.

[obob]

Are you confirming the fact that it is OK to connect a typical 12 v 6a auto battery charger to the terminals

under  the hood that are used for jumping?

 

If so, it hardly seems worth investing in the jumping gizzmo.

 

js

 

As I understand it, once the computers power on and the car is ready to go, the High Voltage Battery is charging the 12V battery.  The gas engine doesn't have to be running but it will run when the HVB gets low.  So there is not a lot of experience of people charging the 12V battery with a battery charger.  I find it hard to believe that the car will be hurt by doing it under the hood with a decent charger.  The purpose of the jumping gizmo is to power things up enough to get the computers running.  I feel good about keeping it in the car.  I have even used mine on another car.  Having accessed the battery out of curiousity, it is really not designed to be accessible for a charge or jump.

 

There are cheaper jumpers that will work on the C-Max.

 

I agree with your accessment of not a lot of 12V battery amps needed to get the car started.

Edited January 7, 2018 by obob

[SnowStorm]

Using a charger at the front terminals works fine.  I had a couple of dead 12V battery incidents years back on my 2013 and used my charger to bring the battery from only a few volts back up to 12V.  I wouldn't ever try to jump or charge back at the battery.  Other comments are (many repetitive):

1. Make sure your car has had all the updates done.  There was a major one related to the dead 12V battery problems and possibly one related to the charging algorithm that helped keep it charged if you only do short trips.
2. If you get a new 12V battery, make sure the battery age parameter gets reset when its installed.  If its not reset, it may affect the charging algorithm in a detrimental way.  I don't know if this can only be done by dealers - you might want to go to a dealer you trust.  Just make sure they do it.
3. Reasons for having a jump starter over a charger is that its quick, you don't need AC power, and you can use it to help someone else if they ask.  With so much electronics in cars today I hope to never use jumper cables again.
4. The actual current needed to "jump start" the car is quite unknown.  The jump pack must push enough current through the 12V battery to bring its voltage up momentarily to the point that the electronics starts working.  Then you "start" the car and the HVB takes over using the DC-DC converter.  I would think, though, that most any of those new jump packs will work fine.
5. The 12V power outlet in the back luggage area is on all the time.  You might try an extension cable and voltmeter back there.
6. Gas mileage on short trips can vary wildly for several reasons.  The numbers are fun to watch but don't mean much.
7. If you want to see lots of technical info about the car, get the Forscan software and a wireless OBDII interface (there's lots of posts about it on here).

At 146k miles and 49 lifetime mpg our C-Max remains the "best" car we've ever had and is expected to go to 250k or 300k miles (or until someone throws a 250+ mile EV our way!).

[jestevens]

I just went through this - a friend drove me around in their car so my 2013 C-MAX just sat there over the weekend, short 12 mile trips to and from work followed by the two coldest days in the last 10 years.  3 times now went I went out to clean off the snow and when I went to unlock the door with smart key the car was "dead" and I had to use the emergency key in the FOB to get it open.  As soon as I started the engine everything was fine.  I had just changed the FOB battery about 4 months ago and neither FOB worked so I suspect the car was going into a deep sleep mode to protect the battery.

 

As someone else said, you really shouldn't have to run the engine on the C-MAX to charge the battery since there is a 12V inverter that is powered from the high voltage battery.  You just need enough juice from the 12V battery to have the computers boot and close the relay contacts on the high voltage battery - then the car will use power from the HVB to spin the crankshaft and start the car and the power goes from the HVB to the 12V inverter which charges the battery.

 

Just for good measure I went out on the cold mornings and started the car, I also hit the red MAX DEFROST button which will override all of the temperature controls, blast heat out the vents and ensure that the engine keeps running.  I guess I sort of ignored my own advice about not needing the engine but I figured one thing the battery does need is heat, and it was 4F outside for a few hours.

 

I actually made a few trips yesterday and there were no issues this morning so I have to assume that it was indeed that the battery was low, probably old and not keeping a good charge due to the cold.  I think these batteries also have less cold cranking amps because really they don't need it, they aren't trying to turn over an engine, that's the job of the HVB.

 

I think just to be safe I'm going to arrange with Ford service to have the 12V battery replaced as I still have the original which by the VIN that car was produced May 2012??  I have all of the software updates which you should visit the service shop and get if you don't have them already.

 

I think they are doing a special for $99 motorcraft battery.  The 12V battery on its own ranges from $87-$150 depending on where you buy it from.  Plus it looks like you'll need some Torx and metric sockets to get to it, pull up some panel covers, disconnect some vent ductwork.  I did it with my Prius, they don't make them easy to get to because it's an item that seldom needs replaced.  All things considered by the time I buy the battery and the tools and take the time it's probably just worth letting Ford Service take care of it as long as that special is still going on.

 

I know some folks who don't drive very often or have classic cars use battery tenders but I think it would be pain to hook one up in this car unless you do it at the jump points under the hood?  I remember panicking a little when the guys in the garage across the street said "oh we work on hybrids!" then opened the hood on my Prius and were trying to figure out where to put jumper cables when they didn't see the battery.  These cars have multiple expensive computer modules that don't like being shorted out.

Edited January 8, 2018 by jestevens

[cr08]

One thing SnowStorm posted above is very apt especially with battery replacements and that is getting the battery age reset in the car. Ours and most newer vehicles will actively monitor a battery SOC and age and modify various parameters such as charging and how long various modules stay running after the car is shut off. If this counter is not reset when the battery is replaced, it could skew certain things including charging rates. It is also a good idea to use the same type of battery and do not attempt any kind of 'upgrades' for this same reason. It is expecting a given type and size of battery.

 

Good thing is if you DIY the battery replacement, the counter is easily reset through ForScan.

[Jack Schmidling]

Thanks for all the help again. Think I have a fair understanding of how it works.

 

A few more things came up that I can't find in the manual.

 

1. I ordered a cigar lighter DVM but in the meantime, I can not get a reading with my usual DVM in the lighter socket. Is there something that needs to be enabled?

 

2. When I get near home, the EV box starts to show EV+ and googling that produces some gibberish that makes no sense. What does this mean.

 

 

3. On seemingly random occasions, a gremlin starts sending Morse code and I haven't a clue what it means. Usually dit dit dit dah as in V sometimes some other character included. What is this?

 

4. If I drive very cleverly, by the time I get home the HVB is nearly depleted. This seems counter productive to starting again in cold weather.

 

Thanks,

 

js

[cr08]

1) Obvious question but is the car running/in 'Ready' mode? The two front ports will shut off when the car is off. The one in the hatch is on at all times. Otherwise nothing out of the ordinary on these. Check the normal stuff like using another device to see if it gets power, check fuses, verify you are touching your leads in the right spot (positive lead should be dead center in the bottom of the socket, negative to the outer metal casing).

 

2) EV+ Is a smart function where the car recognizes often visited locations such as home and work. What it does then is within 1/8 mi or so to those locations it ensures there is a healthy amount of charge remaining to make it the remainder of the way on EV only and will hold EV mode as long as possible. Allows it to shut down the engine and keep it off to your destination.

 

3) Not sure on this. Where is this coming from specifically? When does it happen? Etc..

4) With hybrids I don't see this being as big of a concern especially in cold weather. The engine is going to need to come on at some point not too far out anyways. Especially if the car rests, the battery is going to cool down and depending on how cold, the engine's going to need to supplement it anyways until things warm up.

[stolenmoment]

2+4) EV+ indicates that the computer will let you run the battery down further instead of running the ICE.  If you have the threshold displayed in the left screen, it goes much higher when EV+ is displayed.

[plus 3 golfer]

Jack, I don't have the "jumping gizmo" but use my battery charger at home if the car won't "start".  The advantage of the jumping gizmo is that if you are away from AC power and the 12 V battery fails to "start" the car, the jumping gizmo will likely save you time to get going again.  As a hedge against needing a jumping gizmo, I carry my jumper cables in the compartment under the driver's seat.  

 

When my 12 V battery was failing (wouldn't always start next morning), I used my battery charger to charge the battery from the front post on several occassions until I was able to go to the dealer for a battery replacement. 

 

In that same under driver seat compartment where I store my jumper cables is room for a tire "tread" patch kit in case I might get a screw / nail in the tread and can't make it to a tire shop or home before the tire might go flat.  I will not carry a spare as we travel a lot and it would take up too much room in the hatch area.  

[jestevens]

EV+. there's a GPS module in the car and if you visit the same location, like 11 times - the car figures out that you like to come here a lot.  It will allow you to run on electric only with extended range within vicinity of one of these spots and draw down the charge on the HVB.  I guess the idea is that let's say from home you might restart the next day from a cold engine and it's going to have to run to warm up the engine, catalytic converter and possibly the cabin anyway at which time the battery would be charging up.  Remember that even if the high voltage battery gauge shows empty on the dash, the battery management software typically keeps the battery within 20-80% state of charge to preserve the longevity of the battery, so despite what the gauge says it's never physically completely empty or full unless the car sits for a very long time or I guess goes up or down a very steep, long hill.

 

Someone else here explained it a while back..

Edited January 18, 2018 by jestevens

[chrisl]

3. On seemingly random occasions, a gremlin starts sending Morse code and I haven't a clue what it means. Usually dit dit dit dah as in V sometimes some other character included. What is this?

 

Is it through the radio?  Do you have an old-ish cell phone?  It happens to me with polycom tabletop teleconferencing units - if there are cellphones nearby, when they do their handshake with the tower (and maybe when they're getting data) they can cause interference with the telecon unit and it sounds like morse code.

 

I checked out this thread to check on jump devices and whether the ones that plug into the lighter socket would work.  My 12V was dead this morning, I think due to either a software glitch or switch being flaky because I think the radio didn't turn off automatically after I shut the car down and opened the door yesterday.  The car is also a 2013 with the original 12 V, so it could be time for a new one.  I started it today with a cheap 12V 2A/6A charger that I got years ago from Harbor Freight.  I used the posts in front and only waited about 30 s after hooking it up to turn on the electronics. They don't draw that much current and I already knew the HV is used to start the engine, and the 12V is really just to boot things up.

 

Time to head off and get a jumper pack and then get the 12V replaced when I get around to getting the door latch recall done.

 

btw - I routinely leave my car for weeks without starting it and have had the battery go dead twice. Once when I left the headlights on at work, and this time when I think the radio didn't turn off.

Edited February 4, 2018 by chrisl

[jestevens]

Next time you go to the dealer ask them to make sure your car has all the 12V battery updates.  There was a customer satisfaction letter that was sent out about it but I forget the number.  I have a 2013 SEL and Ford kept telling me that my 12V battery was good but I started to have issues with the smart key not unlocking the door.  In my opinion it was worth the $200 (parts + labor) to let them do it.  The battery alone costs at least $120 on sale from Motorcraft - it was going to cost $150 on Amazon + $30 shipping so why not just let them do it considering it's hidden under the floor in the back.  I did replace the 12V battery in my Prius and the procedure is about the same, not very much fun outside in 4F weather.  So between replacing the 12V and the coin cells in the FOBs no more issue.  I had already replaced FOB battery a few months prior to having the unlock problem so I knew it wasn't that.

 

Hopefully you already know about the emergency key that is hidden in the FOB?  Useful if the battery dies and you can't get the car unlocked.

Edited February 5, 2018 by jestevens

[kyledamron1]

Woke up on Tuesday to a dead battery in the car. Still on the original for my 2013 with 71,600 miles. I put my booster pack on it and worked just fine since. I had problems with Sync the day before where it would not play audio or anything, so I think that drained the battery. Otherwise it seems to be working okay.

[cmax-nynj]

I have had a number of dead 12V battery moments and I'm comfortable using a booster pack under the hood to start the car.  However, I want to invent a way so that I can plug the booster pack from inside the car when battery is dead (a solution for the worried wife).  I'm thinking of running a Wire (w/Fuse) from the Positive terminal of the 12V battery (under the trunk); add a ground wire and find a male adapter that would fit my booster pack.  I wonder what the fuse amperage should be for safety; and the minimum thickness (gauge) of wire I need to use.

Edited February 11, 2018 by cmax-nynj

[plus 3 golfer]

I have had a number of dead 12V battery moments and I'm comfortable using a booster pack under the hood to start the car.  However, I want to invent a way so that I can plug the booster pack from inside the car when battery is dead (a solution for the worried wife).  I'm thinking of running a Wire (w/Fuse) from the Positive terminal of the 12V battery (under the trunk); add a ground wire and find a male adapter that would fit my booster pack.  I wonder what the fuse amperage should be for safety; and the minimum thickness (gauge) of wire I need to use.

I'd use a fuse tap and plug it into a spare fuse slot or a used slot in the front or rear junction box which are hot all the time.  Now just wire up the fuse tap to a compatible plug for your jump start.   

 

You could make it easy for your wife by also wiring in a momentary pushbutton on the driver's side and leave the jump start connected all the time. So for a no start, one holds the pushbutton in while starting the car.

[jestevens]

No issues since I had my battery replaced - considering it was the original battery and mine was built in May 2012 maybe some of them are genuinely reaching end of useful life?  Ford said battery was good but car was starting to act funky.