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Adding Extra Battery Power to FFE

Posted: Mon Sep 28, 2020 10:04 am
by Motorscm1
Hi All,

I am new to this Forum but I have been working in PHEV and EV's for years. I just got a 2013 FFE. So far I have added a class 2 trailer hitch for my bike rake and a small trailer I take to hardware stores . I also had Linear Logic send me the prototype Scan Gauge board which was $25 plus shipping. Next I plan on adding extra battery power using the same method that SEFS used for the Chamdeo charger. I figure I can fit about 30kw in the trunk of Dow Kokum cells that I acquired from Oakland University in Rochester, MI. If successful, I will share the results. Shooting for 200 mile range!!!

Re: Adding Extra Battery Power to FFE

Posted: Mon Oct 05, 2020 6:15 am
by Motorscm1
So I worked on my 2013 FFE this weekend and added 7kw as a proof of concept and the car took the extra power with no issues. I tied into the main positive behind the seat and ran a main negative "Back to the Future 3 style" from the main Negative on the TCM out of the hood and through the back window because I live in Florida and it's been raining for days and my garage is a one car with nowhere to work. I ran 2 - 150 amp DC circuit breakers to spilt the aux. pack to "safer" voltages and run a third circuit breaker separating the main pack, before the tie in relay. I used a set of Tyco 12 HV relays to control the power feed. When I turned on the system, my FFE prototype scan gauge showed 80 amp going in at 1st and leveled off to 50. The surplus gauge on the left side of the dash started adding miles shortly after I turned on the relay and I added 5 miles as if I was at a charger while one leaves the vehicle running. I was curious if the car would throw a DTC code while moving and had my tow dolly ready if it did, but no problems. I have the 150 amp dc circuit breaker before the relays as a fail safe, so if the car is under heavy torque, it will automatically disconnect the aux. battery. So the FFE will accept additional power using the charge dump method pioneered by Cal Cars for the Prius. Now I just need to run a more permanent negative cable from the front of the car and add more batteries. If you are going to try this, "I highly recommend that you have a qualified electrician help you" as high voltage will kill you!! Be sure to add the proper circuit breakers as well. Your charger needs to galvanically isolated as the car will throw a hard code if is sees a path from the HV side to ground which cheap chargers will let happen (plus it's dangerous for you). The good news is that up to the GVWR of the weight car, you can add that weight in batteries. I plan on adding 30kw which is around 450# or the weight of 2 robust grown ups. So big success!!!!! I figure I will end up somewhere between 175-200 miles based on my driving style. At least I can get to the MCO airport (without stopping to charge) and back which was the original goal.

Re: Adding Extra Battery Power to FFE

Posted: Mon Oct 05, 2020 10:54 pm
by Dobrinia
Good afternoon!
Can I have a photo?
I am planning an extra battery too!
What elements are you going to use to assemble an additional 30kW battery?

Re: Adding Extra Battery Power to FFE

Posted: Tue Oct 06, 2020 4:47 am
by skyguy_6153
My interest is certainly peaked :shock: All you'll need now is a Chademo or CCS charging system!

Re: Adding Extra Battery Power to FFE

Posted: Tue Oct 06, 2020 6:05 am
by triangles
I had thought about a similar project but I was leery of the rear springs being able to hold up the extra weight. I'm interested to see how this works out.

Re: Adding Extra Battery Power to FFE

Posted: Tue Oct 06, 2020 10:32 am
by Motorscm1
https://imgur.com/a/fJ1T2um

I posted 4 pics on IMGUR(see link above). One of the car after the weight was added. I will add some extra coil springs or Air shocks long term (Similar to Plug-In Prius projects.) Pic of the temporary battery setup. The negative HV lead coming out of the hood and going in the rear door. And one of the tie in with a new aluminum plate on the TCM. Hopefully the links works - it did when I posted this.

On the element question: I will be using 74 Dow Kokum cells (batched 16 per block - 67# each) that are 11inch X 11inch X12inch and I will use (2X)28 - A123 cells after I detach the factory BMS and add my own. It should add around 450#s to get an extra 30kw or so. More than enough for me. Frankly, I have not needed more than the OEM battery so far. More curious if it could be done.

As far as Chademo, that has been done already on another thread (as I am sure you are aware) and the parts are for sale. In my area, there are only 2 Chademo chargers and they are broken 120% of the time.lol. If I want CCS, I would just buy a 17 or 18 FFE as they are around the $10k mark these days

Hope that helps

Re: Adding Extra Battery Power to FFE

Posted: Wed Oct 14, 2020 3:44 pm
by Anti_Climax
This bodes well for the genset trailer idea I was throwing around.

Thinking of repackaging the SOBDMs Sefs used for the 30kW charger into a portable configuration that could be fed from a 20kW generator head and tapped into the DC bus. It would allow "hybrid" operation on the highway or could just be a portable 30kW charger to use on mains rather than running the generator.