Discussion in 'PHEV or Plug-in Hybrid Electric Vehicle' started by krousdb, Jul 22, 2009.
Just ordered a 4kw conversion from engineer.us. More to come......
I am anxious to see what you think of it. I was VERY intrigued by the price. Enough that I am considering keeping the 05 to convert. With your background, I'm sure you will be able to shed light on the kit and am anxious to hear your thoughts and findings.
What is the lead time for delivery for the enginer.us kit?
Lead time is 15-20 days. On my long drive back from GDE 2009 I had time to consider the possibilities of this kit. I made a list of Pro's and Con's and found that this is kit fits my needs much better than the competition. I especially like the scaleability. The BMS is very informative and provides useful information. It can easily pinpoint a bad cell and that bad cell can be replaced in about 30 minutes at a cost of $70.
May want to correct the title of this thread so people will find it in search.
The company is called "Enginer"... not "Engineer". Only 1 "e" after the "n".
Can you provide a few more details? I could not find it in a Google search. I'm one of those crazy hypermilers that are not steeped in Prius knowledge - I am considering a MIMA like conversion for my SVT - I'm only getting 60-61 mpg and I really would like to do better than that ...
Thanks, Eric. I've updated the thread title.
Dan, do you intend to enhance the range with more batteries later?
This is interesting (thanks to both of you for the link info). I shot them a quick note. I wonder if they are willing to think outside of their box ...
Short answer is YES! I ordered the 4kw kit and an additionall converter to experiment with. Once I determine the best way to use the added EV/ ICE assist on my commute, I will then be able to "tune" the installation with additional batteries and converters. As long as you are willing to give up trunk space, you can add capacity in 2kw increments. The upgrades are as cost effective as well.
BTW, this should work with IMA also.
For those of you that don't currently have a hybrid, check this out.
I am hoping that they will consider the Focus for one of the kits. Unfortunately, they have no plans to offer the components to people who want to do their own integration.
I am considering a 5th wheel for my Contour SVT. Nothing serious yet, just doing a little preliminary research. If I can figure out how to make the costs affordable, it will become serious very quickly ...
Great news Dan, I can't wait to hear about your results.
Just a word of caution wrt Li technology (although I am sure you already know this). Be very careful about the manufacturer's limitations on SOC - never violate them and try to keep yourself out of the limits. I have many colleagues working in the battery world and there is one universal rule for Li battery chemistry - if you push the limitations of range, you will trash the long term health of the battery.
I just sent them a note asking for pricing info on what it would take to get to ~40 mile AER in my Prius. Be afraid Craig!
Actually, that would apply to any battery chemistry. The BMS handles charge balancing, the charger shuts down automatically when fully charged and and the system shuts down automatically at 10% SOC.
That sounds like a pretty big DoD... are they A123 cells?
No, they are LiFePO4 prismatic cells. 10% is what I remember, but I may be wrong. The point is that it shuts down automatically at a preset SOC or when the BMS senses a problem.
The IMA system suffers from frequent and often excessive use of the battery pack and even though the ICE is very efficient much of the FE losses incurred stems from the penalty of forced regens.
A more modest system like this one would help deepen the OEM pack and this alone would reduce the chances of a forced regen thus keeping the overall FE as high as possible.
They need to provide an example of an IMA retrofit before some folks make the jump.
I talked to those guys in some depth at HF. Little red flags
about offshore build quality went up in my mind. Think
"enginer.cn" as a more appropriate domain for them... note well
that Thundersky has had some pretty serious QC issues over time,
and hopefully they're getting past that. I believe the BMS is
an off-the-shelf unit and they *claim* it tries to do some active
cell balancing, and their DC/DC converter is built in-house for
the purpose but is likely a mod of a relatively stock battery
charger. On the bright side they *are* regulating output current
the right way instead of just banging two packs together through
contactors and hoping for the best.
They do not read the car's notion of SOC over the data bus, but
rather rely on a fixed 240V cutoff point. That's a bit over 2.4
volts per cell, which is a bit high for NiMH and may start
getting into mild overcharge territory. With the way the stock
NiMH pack voltage thrashes all over the place under driving and
regen, they're going to be in and out of supplying energy fairly
frequently. I believe their system pushes about 10 amps into the
car, i.e. about 2-and-change kW. They're implying 10 miles from
2 KWh, which is likely *very* optimistic even for a Prius.
Oh, and that little cylinder mounted above the battery block is
a *fire extinguisher*.
One important thing they've learned which I've been curious about
for some time is just how much current you can inject into the
car's stock system such that it knows about it, i.e. not sneaking
around behind the current-sensor donut to hide the fact that you're
pushing charge into the stock NiMH. They're managing to supply a
steady 10 - 15 amps and not have the car complain about battery
vs. motor current-detection mismatches. I think this is a really
useful bit of info, and supports the questionability of the
Calcars/Pluginsupply approach in my mind. I've often thought
that with a magic supply of 10A coming from "someplace else",
I could basically extend engine-off glides practically forever.
Here is the response I received:
If I'm doing the math right, this would cost $5990 and could be done on a Saturday. Al, feel like a trip to Elkhart?
I just took a look at their site. The good news is that their lifetime cycle degradation information seems pretty realistic. It also seems that their controller is programmable wrt lots of parameters.
Personally, I would set the cutoff at higher than 10% SOC (they spec 2000 cycles at 80% SOC and 3000 cycles at 70% SOC). I would ask them what the charger is taking it to at the top end (i.e. do they consider a fully charged battery at 100% SOC). I bring up these questions because some controllers indicate 100% SOC at a true SOC between 90% and 95%. In order to optimize your DoD for lifetime, you need to know how it is calculated. Ultimately, this will determine your battery cost per mile. According to my back of the napkin calculations, that varies greatly depending on automatic DOD (anywhere between $.02 - $.05 per mile). At the lower DODs, the system will pay itself back. If you run a high DOD (90%) and account for the electricity cost, the system will never pay itself back ...
Separate names with a comma.