Energi Plug In Hybrid and the FFE

[EVA]

I'm driving a Fusion Energi while my FFE is in the shop. A bunch of questions came to mind today while I was driving that car. Mostly around battery life and cycling the battery on the FFE to low levels and fully charging the battery.

This is a guess since I don't know exactly which batteries they put where in the Energi. It looks like Ford used the same or very similar Lithium battery pack to the FFE (or half of the packs). The intrusion in the trunk looks exactly like the one in my FFE. It would also seem logical that Ford would use the same part - why carry multiple battery packs?

From the dashboard, it also seems like there are two batteries in that car, one for the plug in part and the other for the gasoline engine / hybrid part. When the car is in EV mode running off the plug in battery (what I'm calling the Lithium battery here) there is one graph or battery represenation that looks very similar to our FFE battery display. When the Lithium battery is dead, a new display appears that represents a hybrid battery (there is no range estimate on that graph).

Here's where I got to wondering about the FFE battery pack.

On the Energi - that pack in the trunk is going to cycle through fully charged to fully empty a lot. Way more than the FFE. The car only gets 27 miles on a full charge. More than likely people with that car will run that battery down to 0 every day and charge it back up to 100% at night - or twice a day (charge it at work and then at home).

Is there something different about the Energi battery pack? There seems to be concern about cycling the FFE battery pack all the way to 0 miles and 100% charge because that isn't good for Lithium batteries. Aren't the Energi cars going to see much worse effects?

By the way, the plug in battery range estimate is just as bad in the Energi as it is in the FFE. That's a good thing, if Ford comes up with an improvement, they will probably apply it to both cars. Also, when the car got down to 0 miles left in the battery, I was able to drive a couple more miles before the whole Hybrid display took over or the engine started. I've seen people mention the FFE does something similar, goes miles past 0 range.

And then I got to thinking about the hybrid battery - probably the same issue for Prius or any other hybrid. That battery cycles through empty to full and almost constant charging way more than the Lithium battery pack. While I was driving today I noticed the hybrid battery level go from 0 to almost 100% a dozen times. I remember driving a Prius that did the same thing.

What about the life of the battery for the hybrid drive? Isn't that battery being beat to heck, or incredibly mistreated?

Once the plug in pack is dead, the never goes back to that display. In other words the gas engine doesn't appear to charge that battery - doesn't put range in that battery.

 

[jmueller065]

A few observations:
- I doubt that either battery goes completely to 0% and likewise goes all the way to 100%--the readings are probably % of usable capacity--I would bet that those batteries have a bigger reserve than even the FFEs (like leaving 5kW at the bottom and only really charging it to 90%)
- Have you tried the "EV Now" and "EV Later" modes? I think "EV Later" is supposed to charge the battery up
- That is very odd that it would switch from "EV" mode to Hybrid mode--I would have thought that the Energi was just a hybrid with a bigger battery

Back in April, while on vacation, I had rented a C-Max Hybrid. One day when I had some free time I thumbed through the manual which had an interesting item; it said that the Hybrid always tries to keep the battery around 50% of charge so that regen braking can store power, and that there is power available for acceleration.

 

[oilman]

'Back in April, while on vacation, I had rented a C-Max Hybrid. One day when I had some free time I thumbed through the manual which had an interesting item; it said that the Hybrid always tries to keep the battery around 50% of charge so that regen braking can store power, and that there is power available for acceleration.'

I have a 2010 Fusion hybrid and that is the way that vehicle works. The system tries to keep the battery near the mid-point. For example, if I can get enough regen on the surface streets to significantly raise the charge level and then drive on the freeway for 10 miles or so, the charge state will work its way back down to the mid-point, no matter how gently I drive. I have always wished I had a button I could push to store the energy for use later after I get back to the surface streets.

Also, as I understand it, the Energi, being a plug-in hybrid, does have two batteries; one that is used for EV mode only and one that operates only in hybrid mode. I believe that only the EV mode battery is charged when the car is plugged in.

Oilman

 

[jmueller065]

I was really curious about this as it seems like its a little silly to have to install two batteries in the Energi products.

Good old Google found this C-Max FAQ with this entry:

Are there two batteries for the Ford C-Max Energi, for “hybrid” and “plug-in” operation?
No. However, from the user perspective there appears to be two. The software for the drivetrain divides the battery into a 1.1 kWh “hybrid” battery and a 6.5 kWh “plug-in” battery according to an article in Automotive Engineering Online. As far as I can tell, Ford never charges the battery to 100% or discharges it to 0% to prolong battery life. A full charge of the Energi adds about 5.5 kWh of charge to the battery and requires about 8 kWh from the wall (electric meter). When the potential energy is high (at the top of a hill, canyon or mountain) and a long descent is encountered, after the “hybrid” battery is fully charged the “plug-in” battery will start charging. As a test, I drove up American Fork Canyon until the “hybrid” and “plug-in” batteries were completely discharged and the ICE (internal combustion engine) started. I then turned around and descended to the starting point. The hybrid battery was fully charged and the “plug-in” battery had a 30% charge after returning to the start.

and Here is the link to the Automotive Engineering Online article (which also has some details about the FFE!).

 

[oilman]

By golly, it looks like you are correct - there is only one battery in the Energi model. I went to the Ford website and the specifications specifically list one 7.6 kW battery. My previous statement was based on what I thought I heard a Ford rep tell people at the recent National Plug-in Event when describing the Energi he brought. Either my hearing is bad or he didn't know what he was talking about (I'd say 50-50 either way ). Thanks for taking the time to research this further. I learn something new nearly everytime I come here.

Oilman

 

[unplugged]

My previous statement was based on what I thought I heard a Ford rep tell people at the recent National Plug-in Event when describing the Energi he brought. Either my hearing is bad or he didn't know what he was talking about.

Oilman

It is quite possible, no probable, that he didn't know what he was talking about. These guys are not actually Ford employees. Ford contracts them to demo the cars, but their knowledge of the cars themselves is often limited.

 

[EVA]

Thank you so much for the thoughts. It makes sense that, if there is only one battery pack, Ford would work mostly in that 30-25% of capacity area when the car is in hybrid mode.

Funny, the car did try to stay in the middle of the gauge when in hybrid mode.

Guess I have my question about Ford answered - they are managing the batteries very carefully.

And I guess the Prius question is answered also, Toyota tries to keep the charge level on the battery in the middle. They don't whip it from discharged to fully charged.