Enginer PHEV Technical Information

I'm forming a little theory on why the early CalCars and similar
efforts had so much trouble. First of all, 12 amps is an entirely
reasonable to "mismatch" from what the HSD motors are doing --
consider the case of running the A/C hard and recharging a very
low 12V battery at the same time. High A/C will pull a couple
of kilowatts of compressor power to try and cool our sweaty butts
down, accounting for as much as 10 amps from the hybrid battery.
When I was recharging deep-cycles after a night of running small
inverters to light an event this spring, using my Anderson connector
in the back, I was seeing drains of 7 amps at the start which
settled down to about 4 for the bulk of the recharge and finally
tapered off -- discounting the one or two the car itself draws,
let's say that's another 5 amps steady-state.
.
So there you have 15 amps of draw that has nothing to do with making
the car go, and since the HV controller has no sensing into those
current paths for the A/C driver or the 12V DC/DC converter, it just
has to put up with it. I guess this implies that if 15 amps of
discharge is okay, then 15 amps of charge is also okay. All well
under the usual CCL/CDL as reported by the battery ECU.
.
To make things more interesting, the Hymotion people tell me that
their connection is at the stock Prius pack relay connections, implying
that they're on the correct side of the current donut -- i.e. the one
that lets the car see what's going on. And they claim that they can
push 40 amps into the system with no problem at all.
.
So if Hymo is correct, here's my embryonic theory: The calcars people
were trying to use their stupid, blundering contactor-based approach
on the "outside" of the donut at first, and guess what happened? Click,
and immediate HUGE, uncontrolled current spikes between the two packs
that the car could see and go "holy sh*t!" and fire off immediate
error codes. So they worked around it by landing on the other side of
the donut, and then since the car couldn't see what was going on and
thus couldn't coulomb-count the additional "magic current from the sky"
coming in, they had to play all kinds of overly complex games on
the CAN bus.
.
Since the Hymo kit is also a current-regulated type, it is probably much
nicer to the car's electrical system and probably ramps up the feed in
a way that it can tolerate and doesn't exceed any outer limits such as
100A that the stock pack is supposed to be good for in either direction.
Since they play well on the bus, they probably pay attention to CCL and
SOC and don't push things too hard. All this completely confirms my very
early thinking that all such efforts should have taken a current-regulated
approach, and that the whole contactor thing was doomed to failure from
the very outset. I'm really surprised that a bunch of old EV guys who
should know better actually ever thought that this would work reliably.
Well, maybe you can do it across PbA packs and get away with it for a
while, but NOT HERE and especially not with MIXED CHEMISTRIES.
.
So hats off to Enginer for trying to do it the right way; now all they
gotta do is get that QC up to snuff. That shipping damage is just ...
unbelievably lame.
.
_H*

 

Not a bad theory Hobbit. It makes a good deal of sense, but I'm not sure it fits all the facts. The two discrepancies I can think of are:

1. Rudman's PiPrius, he used a nice PFC dc:dc converter and I believe had the same issues with DTCs and had to go inside the donut.

2. I didn't think the DTCs in the contactor based systems usually happened right away, they seemed to occur after driving EV for a while.

Both are mentioned in this link, but pretty short on details:
Prius PHEV Schematics - EAA-PHEV

On the other hand all this happened a few years before I started following it closely, its always possible that by then certain things had become accepted truths that were not necessarily so. It will be very interesting to what will happen when folks try 2 or 3 of these converters.

Hobbit, you might be able to answer a question I had. If the pack is left on all the time, and if the voltage is high enough to pull the OEM battery SOC to an unsafe level, can the Prius dump charge while stationary or in park?

Your comment about Hymotion is very intriguing....

Rob

 

Hobbit you may be right about Hymotion. From this pic:
http://i399.photobucket.com/albums/pp73/HymoPrius/033L5HVwiringattached.jpg
from this thread:
http://priuschat.com/forums/prius-p...ons/53794-yet-another-hymotion-install-3.html
it certainly looks to me like Hymotion is entirely on the outside terminals.

Compared to this pic:
Image:100 1442.JPG - EAA-PHEV
of a 2006 vintage Cal-Cars where you can clearly see the cable coming inside the Hall Effect sensor.

Of course we do have to bear in mind that Hymotion also has a very sophisticated two port CAN controller that sits between the battery controller and the HV controller. This allows it to modify and/or spoof CAN messages between the two, which could certainly allow it to avoid the situations that cause the DTCs. Still very interesting.

Rob

 

What you say is certainly true and I'll freely admit I don't know these batteries that well, but bear in mind a pack is only as good as its weakest cell in terms of capacity. Also my understanding is that as a pack ages it is generally not feasible to swap out individual cells. The discharge curves of cells change as they age (another inaccuracy in trying to use voltage to determine SOC), and are dependent on what they've all been through in terms of their charge/discharge and operating temperature history. A pack can usually be kept pretty well balanced over time because all the batteries have been through exactly the same things. If you try to put a brand new cell in an aged pack, its often pretty much impossible to keep the pack in balance.

 

Just opened Enginer 2010 PHEV Technical Information for Gen III specifics...

Jack

 

Dan,
There is a schematic for the dc/dc converter on the web at
Enginer - EAA-PHEV

 

WOW, 3! That is very cool! Are you staying at 8kwh of batteries or making the jump to 10 or 12 with the third converter?

 

Guess I don't quite get it. 3 converters and four 2kW strings. I can see how you could hook one 2kW string to each converter, but that still leaves you with an extra 2kW pack.

Is your plan to run basically two 2kW kits and on 4kW kit. When all three are running you get ~25-30A, then you finish off your commute on what's left of the 4kW pack?

 

OHhhhh!!!!

So they are paralleled at the 52V side!.

11011011

 

Here are pictures of the latest 4KWH System.




Improvements:
* Ventilation fan for charging and discharging
* Charger exhaust to outside directly
* Extra holes for smart key antenna block
* Quick Disconnect from mounting brackets
* Better cooling in DC/DC converter
* Less frequent beeps from the balancers
* Better component layout for installation and service
* Compact Mottcell batteries

 

WOW! Pretty! Looks very professional.

 

Now that... is a work of engineering.. Very professional and asthetically pleasing

 

Wow that does look impressive.

But does it have two balancers still? Why are their four black boxes?