# Ford C-Max/Fusion Energi battery pack



## Matej (Dec 4, 2015)

Most people on here opt for reusing Leaf and Volt modules, but I am quite interested in the battery pack found in the Ford C-Max Energi and Fusion Energi plug-in hybrids.

It is 310.8V, 26 Ah, and weighs 123.4kg. I assume that is with the OEM electronics attached, so it could possibly weigh quite a bit less. Obviously, it is not as powerful as the Leaf or Volt packs. The appealing part is that the entire pack comes housed in a compact enclosure, which can be easily mounted in the trunk, in place of the back seat, or under the hood. Or all three, depending on how many you can fit in your car.

The even more appealing aspect is that I have seen them sell for under 1000$ on Ebay. That seems like an amazing deal for a 155V 52 Ah (assuming I split it in half) OEM quality prismatic cell lithium pack.

What is keeping me away is that I am scared of the charging. Especially since I have not seen anyone else tinker with these batteries yet. Is there a reason why? What would be necessary to safely charge one of these packs in a 42S2P configuration, or possibly more of them paralleled together?

I would love to hear any input on using these batteries for a conversion.


Documentation on the battery pack:
https://avt.inl.gov/sites/default/files/pdf/phev/batteryCMax0852.pdf

Article explaining differences between the HEV and PHEV (Energi) pack:
http://articles.sae.org/11705/


The car electronics (blue) could be deleted and a custom charger could be mounted in their place. Unless someone can hack the OEM charger and BMS.










Cooling bits attached. The pack is air cooled, so it would be easy to fab up a custom fan setup.










Big picture showcasing the enclosure and the convenient terminal covers. The black ones are quick disconnects to split the voltage.










Here is an article with pictures of disassembling the regular C-Max/Fusion hybrid battery pack. The PHEV pack is two stories tall and uses larger cells, but the structure is very similar.
http://lablog.engin.umich.edu/2013/06/sensing-and-software-for-advanced.html


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## bigmouse (Sep 28, 2008)

I've been eyeing these batteries for a while too. They would be perfect for a high performance plug-in hybrid (low capacity, high voltage).

Do you know if the standard Ford hybrid packs are the same voltage? Is the only difference the capacity?


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## Matej (Dec 4, 2015)

bigmouse said:


> Do you know if the standard Ford hybrid packs are the same voltage? Is the only difference the capacity?


The standard hybrid packs are 281.2V and only 5.0 Ah:
https://avt.inl.gov/sites/default/files/pdf/hev/batteryCMax2158.pdf

Not great for an EV, though at only 34.5kg, I suppose one could parallel enough of them to still get decent range at not too terrible of a weight penalty. But in the end it is easier and cheaper to just opt for the Energi pack.

Of course, as you said, they could work great for a custom hybrid, or the cells could possibly be reused for a motorcycle conversion or something.


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## bigmouse (Sep 28, 2008)

My next project (if I do one, I should have my Tesla Model 3 before I have a chance to start another conversion) would be a high performance hybrid, probably using a Toyota/Lexus hybrid drivetrain again, but with the engine still installed and in a light package (MR2?). The batteries would have to be high voltage (650V for added "torque fill" performance) and low capacity (light weight) as the intention would be to build a track-able weekend racer.


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## coleasterling (Feb 29, 2012)

Hey! Keep these secret! I don't need prices going up for my next project!


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## Matej (Dec 4, 2015)

coleasterling said:


> Hey! Keep these secret! I don't need prices going up for my next project!


Sorry. Felt the same way for months, actually. 

But I finally broke down and made this thread because I would have to ask for help with charging them sooner or later.


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## piotrsko (Dec 9, 2007)

My understanding is they are nicad with power density just above fla chemistry. For cheap they would work, but it seems no one wants nicad when there is lipo.

With some searching you can get them for$250-500 usd out of wrecker yards.


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## Matej (Dec 4, 2015)

piotrsko said:


> My understanding is they are nicad with power density just above fla chemistry. For cheap they would work, but it seems no one wants nicad when there is lipo.
> 
> With some searching you can get them for$250-500 usd out of wrecker yards.


Those are are from the pre-2013 hybrids, and the battery packs look very different. There was also no plug-in version with a higher density battery for the older generation.

The 2013 and newer HEV and PHEV batteries pictured above are all lithium-ion.


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## kennybobby (Aug 10, 2012)

Looks like a bunch of wasted volume and weight for all those screw terminals--half the pack weight is due to fasteners...lol


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## eric1565 (Feb 28, 2015)

TERRIBLE energy density. Need too many for any amt of miles.

Waist of money


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## Yabert (Feb 7, 2010)

eric1565 said:


> TERRIBLE energy density... Waist of money


Considering the entire battery pack, yes... but it should be interesting to know the weight of a single cells. 
Is there somebody who know the weight of a single cell?

Considering the cheap price, the highly configurable cells and the OEM quality, I think those cells should be consider for a small car, motorcycle or a E-bike.


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## coleasterling (Feb 29, 2012)

Yabert said:


> Considering the entire battery pack, yes... but it should be interesting to know the weight of a single cells.
> Is there somebody who know the weight of a single cell?
> 
> Considering the cheap price, the highly configurable cells and the OEM quality, I think those cells should be consider for a small car, motorcycle or a E-bike.


I agree with this assessment. How in the world can you think that threaded posts are a negative for a DIY builder? The pack will do around 125kW and would be very easy to build around. The cells need quite a bit of compression, but that's doable. I've been considering them for a mid-power racing application where absolute minimum weight really isn't that important. I'll likely pick one up within the next couple months and will definitely post some pictures and data when I do!


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## Matej (Dec 4, 2015)

eric1565 said:


> TERRIBLE energy density. Need too many for any amt of miles.
> 
> Waist of money


155V and 52Ah at ~100kg is still lighter than lead acid, and much more compact. Not to mention potentially cheaper.

As stated above, the threaded posts are one of the main points of appeal to me.
The charging is the only scary part.


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## miscrms (Sep 25, 2013)

The price sounds pretty good, but not sure about the weight. My Leaf half pack weighed in at 229lbs, or 104kg, for 12kWh nominal.


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## coleasterling (Feb 29, 2012)

Keep in mind the stated weight doesn't appear to just be the cells, but the whole pack. I'll get accurate cell weights here in a couple-few months.


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## Karter2 (Nov 17, 2011)

i think these are the same Panasonic 25 Ahr cells as being discussed over on ES..
https://endless-sphere.com/forums/viewtopic.php?f=14&t=79639
If so, they are 714 gms per cell .


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## hmincr (Jan 20, 2012)

Anyone possibly know what all the electronics are in the Ford HEV battery case ??


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## Matej (Dec 4, 2015)

hmincr said:


> Anyone possibly know what all the electronics are in the Ford HEV battery case ??


PHEV:








(1) Battery temperature sensor.
(2) Junction box.
(3) Battery energy controller.
(4) DC-DC converter controller.
(5) Secondary on-board diagnostic module.




HEV:








(1) Sensor.
(2) Junction box.
(3) DC-DC converter controller.
(4) Battery energy controller.


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## hmincr (Jan 20, 2012)

Thank you, Matej. Just wondering whether to junk those parts or hope someone hacks them for use.


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## dain254 (Oct 8, 2015)

Old topic I know - just snagged an ENERGI pack for $650, going to pick it up next week! Goal is to replace a 2kwh Volt Lithium module with a pack that is less weight and a few more volts... maybe 15S of these cells at 26AH makes for about 1KWH... should weigh 20-25lbs?


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## EVmattyP (May 12, 2019)

I actually own both the hybrid and PHEV versions of the Cmax. In the Energi model I can average around 220W/mile around town (speeds under 45mph) and about 245W/mile at 55mph. 

It's not uncommon for me to get 24-27miles on a full charge, in a 3700lb vehicle. I do credit the CVT for the increase in efficiency though. Losing it might be fairly harmful to the range...but maybe the weight savings would reclaim that? 

For what it's worth, i just bought (6) LG Chem A7 modules online for less than $1900 shipped. This is about 225lbs of batteries and a rated capacity of approx. 16.8kwh....or about 300% what the cmax pack is.


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## brian_ (Feb 7, 2017)

EVmattyP said:


> I actually own both the hybrid and PHEV versions of the Cmax...
> I do credit the CVT for the increase in efficiency though. Losing it might be fairly harmful to the range...but maybe the weight savings would reclaim that?


The C-Max uses the same type of transmission as Toyota hybrids; the Ford version, used in the C-Max Hybrid and Energi, and the Fusion/MKZ Hybrid, is the HF35. Like the Toyotas, this is often described as a "CVT", but it's not - it's a power-split transmission. It is mechanically simple and allows continuously variable control engine speed, but in electric-only operation it's just a fixed-ratio gearbox (using just MG2, the output-side motor-generator). In other words, in electric mode the motor is not connected to the wheels though any kind of CVT. That is relatively efficient, although MG1 (the input-side motor-generator) must be spinning at very high speed.

The Chevrolet Volt has had two different transaxle designs (for the two generations of Volt), but both are similar power-split designs. Although the Volt configuration is more complex, and the power flow is somewhat different, electric-only mode still means a motor connected to the differential by only fixed-ratio gearing, so the operation (including efficiency) is similar.

The Mitsubishi Outlander PHEV and most recent Honda Accord systems are simpler: they are series hybrids with a clutch to connect the engine mechanically to the output as a single-ratio simple mechanical transmission, creating a parallel hybrid mode. Again, the electric motor is (or motors are) connected to the final output by a fixed-ratio gear train. So even with a substantially different approach to power transmission for the engine, electric-only mode is like essentially every other plug-in hybrid, including Ford's.

Bizarre story: a C-Max Energi owner unintentionally drove one with no fluid in the transmission for a thousand miles, and it survived.


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## EVmattyP (May 12, 2019)

brian_ said:


> The C-Max uses the same type of transmission as Toyota hybrids; the Ford version, used in the C-Max Hybrid and Energi, and the Fusion/MKZ Hybrid, is the HF35. Like the Toyotas, this is often described as a "CVT", but it's not - it's a power-split transmission. It is mechanically simple and allows continuously variable control engine speed, but in electric-only operation it's just a fixed-ratio gearbox (using just MG2, the output-side motor-generator). In other words, in electric mode the motor is not connected to the wheels though any kind of CVT. That is relatively efficient, although MG1 (the input-side motor-generator) must be spinning at very high speed.


That's really good information. I had no idea. I just assumed it was using the mechanical advantage of the cvt to further improve efficiency. 

Since I've paid mine off and I'm in the process of buying a used i3 as our new daily driver I've toyed with the idea of tearing into the Energi to see how difficult it would be to operate as a straight EV. Pull the gas engine and tank and just run an extra battery pack. I don't know nearly anything about engineering or what all would be involved but I just like the idea of yanking the ICE and adding some extra batteries and keep on running it.


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## brian_ (Feb 7, 2017)

EVmattyP said:


> Since I've paid mine off and I'm in the process of buying a used i3 as our new daily driver I've toyed with the idea of tearing into the Energi to see how difficult it would be to operate as a straight EV. Pull the gas engine and tank and just run an extra battery pack. I don't know nearly anything about engineering or what all would be involved but I just like the idea of yanking the ICE and adding some extra batteries and keep on running it.


Mechanically, that would work: just remove the engine, put a dust cover over the opening in the transaxle, and drive. This has been done by some DIY builders with Toyota and Chevrolet Volt hybrid transaxles. In the case of the Ford, since MG1 (the motor-generator connected to the engine through a power-split planetary gearset) would now have no function, it could be removed as well, but that's an internally-mounted component so there would likely be complications. On the control system side, the computers would need to be convinced to operate without the engine responding, and locked in electric-only mode. The biggest challenge might be managing the two battery packs together, especially if they were not identical.

On the other hand, if I had two vehicles and one was a small battery-only EV, I would appreciate the other one being a hybrid for more range (and fast and available refilling) when needed. Individual needs and preferences vary, of course. Also, the C-Max Energi depends on both using battery power to run MG2 (the output-side motor) and running the engine at the same time for maximum performance. Removing the engine means being permanently limited to EV mode performance, with only the MG2 power.


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## coleasterling (Feb 29, 2012)

EVmattyP said:


> For what it's worth, i just bought (6) LG Chem A7 modules online for less than $1900 shipped. This is about 225lbs of batteries and a rated capacity of approx. 16.8kwh....or about 300% what the cmax pack is.


Where'd you get the LG Chem modules that cheap? Have you tested any?


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## EVmattyP (May 12, 2019)

coleasterling said:


> Where'd you get the LG Chem modules that cheap? Have you tested any?


https://www.techdirectclub.com/battery-and-back-up-storage/

Yes, 4 of the 6 are at 62v and 2 are at 56v currently. I'm still trying to sort out the appropriate charger for bottom and top balancing the modules before I use them.


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## coleasterling (Feb 29, 2012)

Not bad, thank you! I wonder if they have the same source as EVWest. My only concern is that they market the cells as solar or backup cells. Would be awesome to see some IR data.


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## riogrande (Jul 13, 2020)

Sorry to jump on such an old thread, but this was all I could find regarding ford energi packs on the forum. I picked up a c-max energi in nov '19 and would like to sqeeze a bit more range in (I wish removing weight was easier). I found this article The best EV prismatic battery cells are Chinese - PushEVs and the vda-phev2 style battery seem to match the ones in these packs exactly. Once my warranty expires, I would like to see if I could find these new ~50ah cells of the same form factor and do a direct swap keeping all other components the same. 

My question would be what are the chances the car would accept these new batteries as a drop in, as nominal voltage is rated the same I would think charging circuitry would not know the difference and just charge until full. Number of cells and output voltage would also remain constant, so the only question really would be whether hard limits for range have been coded in vs. dynamic calculations based on pack voltage seen by computers?

Would have a few projects for the cells pulled out, bike, backup/solar storage etc. Any input is appreciated!


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## menardsy (May 6, 2021)

I was thinking something similares such as the thing is like on battery pack in parallel with the original one. However I think maybe that's the way the car is knowing the battery level is by calculating coulomb. If that is the case then there will be no way it will take into account the secondary battery...


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## Paul Santos (May 15, 2021)

Similar thoughts... Can I find a CALCARS (remember them?) type outfit that will replace the cells/battery pack on my 2013 CMAX Energi? One reason I originally bought the Energi was that I assumed it would be real easy to replace the big battery once the energy density/cost per KWh could justified an upgrade vs. buying a new EV. It would be really helpful if said outfit were near the Boston area.

I did help a friend hack a pre-PIP Prius with extra batteries, but that was 10 years ago, and I need professional help now!


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## Pistol Pete (10 mo ago)

Matej said:


> Most people on here opt for reusing Leaf and Volt modules, but I am quite interested in the battery pack found in the Ford C-Max Energi and Fusion Energi plug-in hybrids.
> 
> It is 310.8V, 26 Ah, and weighs 123.4kg. I assume that is with the OEM electronics attached, so it could possibly weigh quite a bit less. Obviously, it is not as powerful as the Leaf or Volt packs. The appealing part is that the entire pack comes housed in a compact enclosure, which can be easily mounted in the trunk, in place of the back seat, or under the hood. Or all three, depending on how many you can fit in your car.
> 
> ...


Nice ring on marker finger, while working around high voltage ......


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## UglyCarFan (8 mo ago)

brian_ said:


> The C-Max uses the same type of transmission as Toyota hybrids; the Ford version, used in the C-Max Hybrid and Energi, and the Fusion/MKZ Hybrid, is the HF35. Like the Toyotas, this is often described as a "CVT", but it's not - it's a power-split transmission. It is mechanically simple and allows continuously variable control engine speed, but in electric-only operation it's just a fixed-ratio gearbox (using just MG2, the output-side motor-generator). In other words, in electric mode the motor is not connected to the wheels though any kind of CVT. That is relatively efficient, although MG1 (the input-side motor-generator) must be spinning at very high speed.
> 
> The Chevrolet Volt has had two different transaxle designs (for the two generations of Volt), but both are similar power-split designs. Although the Volt configuration is more complex, and the power flow is somewhat different, electric-only mode still means a motor connected to the differential by only fixed-ratio gearing, so the operation (including efficiency) is similar.
> 
> ...



Brian; I'm interested in this old post of yours. Would any of these Ford gearboxes be suitable for use in applications similar to how the Lexus Gs450h is being utilized?


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## brian_ (Feb 7, 2017)

UglyCarFan said:


> Brian; I'm interested in this old post of yours. Would any of these Ford gearboxes be suitable for use in applications similar to how the Lexus Gs450h is being utilized?


Those Ford hybrid transmissions are transverse transaxles, just like the Prius (and hybrid versions of the Camry, Highlander, RAV4, etc); they have two axle-speed outputs. The appeal of the units from the various rear-wheel drive Lexus models (including the GS 450h) is that they are designed to mount longitudinally, with a single output at typical transmission output speed.

The other longitudinal power-split hybrid transmissions which have appeared in production light vehicles are from GM: the Two-Mode from the hybrid full-size pickup trucks and SUVs, and the one in the Cadillac CT6 PHEV. Neither one has the hobbyist technical support for use as an EV drive unit that the unit from the Lexus GS 450h has.


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