How to prolong life and charging capacity of HVB in Ford Fusion Energi

[jj2me]

For those who may be interested in doing some finer-grained monitoring of battery temperatures via the OBDII port (using, e.g., ScanGauge, Torque Pro, Hybrid Assistant, or FORScan), here are a couple of posts here and here from a North Carolina C-Max owner who stopped his battery degradation after he began trying to limit battery temps to below 105ºF or even 102ºF. 

 

From the 1st linked post:

 

"Currently the HVB is down to about 4kWh. I have 63k total miles with 46k EV miles. Most of the lost HVB capacity is very closely correlated to the hot summer of 2015. The HVB overheated a number of times and the thermal cutoff was too high to protect the pack. It did not help that overnight low temperatures were so high the HVB never had much chance to cool off.

 

"The reason there was little of no lost HVB capacity since then is that I now directly monitor the HVB temperature with a ScanGauge. I also actively prevent high battery temperatures by how I use and charge the HVB. As a result I have had not HVB overheating in the last two years lost very little capacity since 2015. "

 

From the 2nd linked post:

 

"The system cuts off EV mode if the HVB reaches 113ºf. At this temp it only allows EV later mode.

 

"I now attempt to control the maximum HVB temp to keep it below 105ºf. I actually prefer a lower 102ºf when possible. ... After the summers of 2016 and 2017 I have no had any additional lost HVB capacity."

 

[EDIT: anecdote on charging temperature rise: About five minutes after completion of charging to 100%, outside temperature was 39ºF and battery temp was 57ºF.]

Edited January 19, 2018 at 08:26 PM by jj2me

[expresspotato]

This does make sense if the pack gets hotter than charging through regenerative breaking than it does just sitting in a warm garage...

[jsamp]

Regenerative braking can put a lot of energy into the battery in a short amount of time.  Much faster than the plug can, even on 240V L2.  Fortunately you can only do regen braking for a short time (until you get to 0mph) so it doesn't really do any damage to the battery.  Regen on downhills can be a little more dangerous.

 

Biggest regen mileage gain I've seen was going down the grapevine in SoCal.  Added 3 miles in under 10 minutes.  Not advisable to do this on a regular basis.

[Fezbearer]

Heh, I used to drive that thing twice a year. I was wondering what kind of recharge one would get driving over it. Not that I really want to because of all the potholes.

[jj2me]

Green Car Reports has an article that says "... the second-generation 2018 Nissan Leaf has a page in the owner's manual that discusses issues that affect the temperature and life of the battery."

 

Here's a capture of that page from the picture in the article (sorry, I tried two ways to OCR it with no luck).  If it comes out unreadable, you can look at the picture in the link above.

 

Edited March 19, 2018 at 06:01 PM by jj2me

[eminaise]

Hello all. I'm a new owner of a new 2016 energi.  It sat on the lot for 2 years until I bought new in Jan 2018.  I've put 2,900 miles on it since Jan.  It always says 15-17 EV miles when full (level 2 charger at home).   Full charge to deplete = 5.4kWh.  Shouldn't it be 7.2kWh?  If it sat on the Ford dealership lot for 2+ years is that bad for the battery?

Edited April 24, 2018 at 03:19 PM by eminaise

[murphy]

1.5 kWh is dedicated to hybrid mode and is not available for EV mode.   It's 7.6 - 1.5 = 6.1.  Then there is the reserved portion so the battery can never be discharged to 0 which would destroy it.  I think that is 0.5 kWh so that drops it to 5.6 kWh which is in the ball park with your 5.4.  How cold is it?  You won't get the maximum number until it is 72° F outside.

[bdginmo]

5.4 kwh is a good ballpark figure for a full charge to the moment of the hybrid switch over. I think murphy is right that 5.6 kwh is probably the ideal figure, but I still consider 5.4 kwh as like-new. 

 

I think mine was maxing out at 5.5 kwh when I drove it off the lot.

 

If you're getting 5.4 kwh then you're okay.

[KenP]

I have a 2017 FFE in Florida with 24,000 miles on it.  I'm getting 23 miles of electric range.  Any advice for improving cooling of battery when charging in a garage in warm climates?  Does anybody open their trunk, or leave a window down? (will this help?)   After two hours of L2 charging in my garage, the trunk temperature was 100 F while the garage air temp was 83 F.  I used to have a Volt so didn't have to worry about battery temperature as much.   I've though about just doing L1 charging from midnight to 7am during the summer?   Thanks.

[murphy]

The battery is cooled by air drawn from the cabin.  There is an intake vent on the shelf behind the rear seats.  Make sure there is nothing blocking that vent.  During charging the battery cooling fan exhausts underneath the car.  120 volt charging is less efficient than 240 volt charging.  The incoming AC has to be rectified to DC and multiplied up to over 350 volts DC to charge the battery.

[jsamp]

I have a 2017 FFE in Florida with 24,000 miles on it.  I'm getting 23 miles of electric range.  Any advice for improving cooling of battery when charging in a garage in warm climates?  Does anybody open their trunk, or leave a window down? (will this help?)   After two hours of L2 charging in my garage, the trunk temperature was 100 F while the garage air temp was 83 F.  I used to have a Volt so didn't have to worry about battery temperature as much.   I've though about just doing L1 charging from midnight to 7am during the summer?   Thanks.

 

Any time you can charge when the ambient temps are cooler is going to be better.  If you can do night time charging I'd go for it.  I don't know if L2 vs L1 has a large effect on battery temp, but logic says slower charging would result in a cooler battery.

Edited May 8, 2018 at 06:28 PM by jsamp

[Blastphemy]

I have a 2017 FFE in Florida with 24,000 miles on it. I'm getting 23 miles of electric range. Any advice for improving cooling of battery when charging in a garage in warm climates? Does anybody open their trunk, or leave a window down? (will this help?) After two hours of L2 charging in my garage, the trunk temperature was 100 F while the garage air temp was 83 F. I used to have a Volt so didn't have to worry about battery temperature as much. I've though about just doing L1 charging from midnight to 7am during the summer?   Thanks.

 

Ford already thought about all of that. If you had to open the trunk or windows when charging in hot weather, Ford would have told you. I charge in California when it's 110 degrees outside with no problem (and the battery gets much more EV mileage on a full charge in the heat than it does in the cold). So no need to worry, no need to waste time with L1 charging, and no need to play games to (supposedly) protect your battery. That having been said, charging overnight is always the best choice for your car, your wallet, and the power grid. But if you have to charge in the middle of a 100-degree day, don't worry about - do the charge. It's much nicer to drive with the battery than on gas, after all, and if your power comes from renewable sources, then it's more environmentally-friendly too.

 

Some fanatics on this forum do silly things like not charging fully, or setting EV Later mode before the battery is depleted. They're not accomplishing anything (but if it makes them feel good, I'm happy for them - just don't get caught up in this battery hysteria). Your battery may lose a little range over time, or it may not. There are so many factors affecting that eventual outcome that stressing over it and playing battery roulette won't make a difference. Charge the car when you can, drive the car as you like, enjoy the ride, and never think about the battery again.

 

Anyone who stresses out about such a small battery should have bought a BEV (fully electric car), a Chevy Volt, or a Honda Clarity.

Edited May 14, 2018 at 04:51 AM by Blastphemy

[KenP]

Thanks for all the wisdom on charging the battery.   

[16vjohn]

Not using the battery to prolong the life of the battery is the first EV fallacy... Just drive the car in auto and let the ECU decide when it's time to supplement a hot battery with the engine. There's a lot of credible evidence to suggest time/age is just as hard on the battery as anything. If you look at the lithium battery studies in academia, it's common to see capacity sharply drop in the first 3-5 years... even if you don't use it and keep the state of charge at ~75%, it's still going to degrade. You may find that the battery still degrades at an alarming rate, even if you think you're treating it right. Drive more, worry less.

 

If it's really going to give you heartburn, consider looking for a PHEV or BEV with active water cooling, like a Volt or Bolt.

[Davidoo]

I just checked how much my battery capacity has dropped on my 2017 Energi.  I ran it today until the EV mode ran out and it switched to hybrid mode.  Unfortunately, I believe the heat in Phoenix has contributed to a big degradation in just a little less than 2 years.  My battery only was able to put out 4.4 kwh today.  I didn't pay any attention when I first got the car, and probably did everything I shouldn't have....I charged it multiple times a day, even in temperatures over 110 degrees.  I drove it on the freeway without concern.  The manual and the dealer told me to just drive it normally and it didn't matter when I charged and how much, just treat it like you would an extra gas tank and use the darn car.  So, with only 17,000 miles I've lost about 20% capacity.  

 

Now, I'm also not sure the other posters who drive like me are not also correct.  I should just enjoy the car (I'm currently getting over 100mpg) and not worry about protecting the battery.  And who knows, just sitting in this heat where my garage is 125 degrees in the summer, might have degraded the battery that much even if I hand't used it or abused it?  I drive the car very gently and when just going to and from work, a 15 mile round trip, I can go all week without the engine starting and still get over 20 miles per charge....so I guess not that bad.  But, if I've lost 20% in 17,000 miles, what will it be like at 50,000?

[jasper7821]

My 2015 has 62k miles and I am in AZ too and I have a 70 miles round trip commute to work and work in the middle of the desert with zero shade and I charge on 110 there during the day and when I get in my car at the end of the day it's 140-150 degrees in the car.

And at night it's about 105 in the garage and I charge on 220.

My car uses 4.5kw now until the battery is out. But when I get to work (about 1/3 city and the rest freeway and rural road) it usually says 20-24 miles EV. When I exit the freeway, I have about a 4 miles road until I get to work. I use the Empower screen and can usually stay in EV mode until just about up to the guard gate unless there's cars behind me and I have to speed up and use gas.

 Several months ago I think I was close to 5kw, so it's gone down almost .5kw in the last several months. For the first two years I was in California and now I'm in the miserable heat, so I think being in the heat has degraded the battery more than being in nice weather.

[bdginmo]

One thing we don't know is if the degradation is linear. In other words, just because you lost 20% in 17,000 miles doesn't mean you'll lose another 20% in the next 17,000 miles even if all other things are equal.

[My14Energi]

2014...74k miles...getting 4.5kwh from full charge/discharge now. About 18 solid miles depending on speed and a/c use

[Davidoo]

2014...74k miles...getting 4.5kwh from full charge/discharge now. About 18 solid miles depending on speed and a/c use

 

That is good for you.  My car has 57k less miles and 3 years newer and now I get about 4.4kwh.  

[jsamp]

When I checked last year at 50k miles I was at 5.4kWh, but I'm known to baby my battery.  Haven't checked lately.  I was going to check in a couple months at 60k miles to compare.

[shaggy314]

Who the hell buys a car, fairly expensive car, and then doesn't use the a/c? Dumbest thing i have heard. All this car is is an enhanced hybrid. Forgot all this charging and battery crap, whats your mpg? Thats all that matters.....mpg. My lifetime avg is 43.2 mpg right now. That's blasting a/c every single day, every second i am in the car....43.2. Thats the number thats important.

 

Hehe, amateur; my lifetime average was 96.5 MPGe... (and 219.8 watt/mile) before I sold with a range around 14. This was over 65,000 miles and 4.5 years. I'm sure there are hyper-milers who would laugh at my numbers too.

 

If you want to ruin your battery, absolutely ignore charging and battery crap; better for you to get the Hybrid. If you want the most out of the battery (a consumable), charge to 100% as close to departure as possible. Don't sweat it if you cannot. Things that degrade your battery are heat, high charge, and low charge states. Be realistic you cannot win only try to extend the life of your most expensive part if you can. Certainly use your AC, but also you can be smart. Run the AC while you are plugging in. Precondition the car as Ford allows. I had a sunroof that I only closed with the AC on...

[shaggy314]

One thing we don't know is if the degradation is linear. In other words, just because you lost 20% in 17,000 miles doesn't mean you'll lose another 20% in the next 17,000 miles even if all other things are equal.

 

I believe Teslas show your first year is the worst and then it levels off. I think Leafs could offer a similar usage, but I'm guessing it is people learning their cars. My Fusion was gradually getting worse and I never showed big drops, just slow decline.

[bdginmo]

I have 65k on my vehicle. I got 5.3 kwh on a full discharge today. The charge time was right at 2.0 hours. I have a little bit of degradation, but not bad at all. I don't charge during the summer. I will go months at a time without ever charging the vehicle during the warm season.

[My14Energi]

Trivial change in 70k miles. Just drive and enjoy your car folks. Put your pen and paper down and stop analyzing.

 

Oh, and by the way. My current mileage is with the swap of summer Z rated tires instead of the factory low resistance tires. So even less of a difference in reality.

Edited April 23, 2019 at 05:02 PM by My14Energi

[jsamp]

For one, 22% degradation in 70k miles is not trivial.

 

But the reality is that those screen grabs do not tell how good your battery is.  Yes, you got 5.3kWh at 20k miles, but that included part of the hybrid portion of the battery.  The only way to compare apples to apples is to do the test where you drive from 100% charge to the point where it switches to hybrid mode and record the kWh used.  The kWh for that test compared to 5.6kWh for a new battery tells the degradation.

Edited April 24, 2019 at 05:19 AM by jsamp