New MIMA Thread

[jsnable]

Mike,

Funny you mention the Aptera specifically. I have a deposit down on the electric version - we'll see if that happens first, or a boost pack for my Insight w/MIMA...

Glad to see MIMA back at this forum.

Jay

[Mike Dabrowski 2000]

A lot of user feedback about operation can be read here:
http://www.99mpg.com/mima/people/

Many other questions are answered here:
http://www.99mpg.com/mima/faq/

Jay,

I hope we have an easy plug in booster pack option soon, that is the missing piece the MIMA concept.
Spring is coming, and with the better weather, who knows what may happen?
An electric Aptera is a fitting replacement for an Insight in my book.

[IamIan]

one of my long list of projects is a new display for my MIMA.

There is nothing wrong with the current display ... but I am a tinkerer .... and I have been thinking it would be neat to have amp numbers going in on regen and coming out on assist on a digital display.... Since MIMA already ties into all of the needed information and displays a version of it on the LED bar graph .... I was thinking the easiest way to do this would be to just tap into the LED outputs for the MIMA display and run it into a small circuit for the digital display.

Anyone else already done this?
Anyone have any suggestions to add?

[Fenrir]

I'd love a digital display as well. Feeding the LED lines into a separate circuit which calculates the current is an interesting approach which I hadn't thought of.

I envision a digital display replacing the current display. Some of the LED lines could be retasked to some sort of serial protocol to send data to a more intelligent display.

Actually this could probably be accomplished without replacing the current display, by using the currently unused light sensor lines for the serial connection.

Serial communication would allow delivery of more info than just amps in/out. Pack voltage would be great to have, but I don't recall whether MIMA is aware of the pack's voltage or would be able to calculate it without a hardware mod.

Implementing a serial protocol in assembly would be tons of fun, I'm sure.

[Mike Dabrowski 2000]

I am meeting with my cousin that did the MIMA board layouts this weekend, and since the waiting list has grown past the 10 required units, I need to get going with another batch of boards. I am swamped with lots of other projects, so I don't see the time to source a display and develop the hardware for an LCD.

The serial com is not a big deal, and I have several serial routines in my library of old projects.
The battery current is already determined in the MIMA system, so outputting a digital amp value is no big deal. The display would not need any computing ability, so just the serial or parallel LCD, and a way to mount it would be required.

As Chris indicated, we should be able to just use the opto detector lines for the serial com, and still retain the led bargraph.
If the display has graphics capability, and is large enough, we may be able to totally replace the led display, in which case the other control lines would be available for a touch screen interface or for a parallel LCD control.

A bit higher level of this display would be to get an LCD with a touch screen, so we could change parameters and display function. There is no reason to retain the led display,but since we could have both the led driver and the LCD driver in the code, and simply switch drivers depending on the display.

If one of you MIMA guys wants to source a serial LCD, write a detailed operational spec on what to display, and how it would want to be controlled(user input), I can write the driver code for it, and if the hardware can be finalized before mid May, I should be able to add a PC board interface for it (if necessary)to the MIMA boards order. The final code can be developed while we wait for the hardware.
We have over 50 users, if you guys can work out the details of what display is best, at a reasonable price, with good availability, with enough resolution to display what we need, I can make it work. The first MIMA open source design team effort. Go for it.

[Mike Dabrowski 2000]

I just got a call from these people.
http://www.boundlesscorporation.com/Products.html
They are interested in designing a booster pack for our Insights.
I sent them a preliminary spec, and asked for a ball park price.
The spec I chose:

Battery pack spec:
Basic requirement
Voltage: ~180VDC
Capacity: 25 to 50AH should be sufficient
Controls: Adjustable constant current output from 0 to 50A, voltage range of stock pack under current limit 120VDC to 180VDC
Analog or serial digital control
Charger: 120VAC full recharge in 8 hrs or less.
SOC feedback : either analog or serial digital

Advanced spec:
The booster pack can be recharged from stock battery regen system with adjustable charge rate of 0-50A
Solar charge ability (dc/dc charge capability)

Pack needs to shutdown if any safety issues with pack develop, as well as having a dedicated fault output line.
It should be interesting to see what they can offer.

[Willie Williford]

What about a "drop in replacement" pack?
All of the replacement packs are still useing the old (battery) technology.
I see that they are in the Boulder, Colorado area. Is there someone in that area that would like to go by and "check them out".

Willie

[Mike Dabrowski 2000]

From our short discussion, it sounds like they get the cells somewhere else, and package them with charge control and safety circuits.
The company only has 18 people.
The guy I spoke with Phil Lyman has an Insight.
It did not sound like they would be interested in trying to build a full drop in replacement, but I can ask the question when I speak with them again.
It may be best to give them a day or so to respond to the booster pack question and see where their ball park price falls, before we ask about the drop in replacement pack.

[joecvt]

If they do not want to build a drop in replacement pack, perhaps they would be willing to assemble the 20 packs of 6 cells (for Insight specs). I would imagine if an Insight owner is willing to change a whole pack themselves, they may also be willing to replace the individual 20 packs of 6 cells.

JoeCVT = Just your average CVT owner

[gpsman1]

Funny, by co-incidence, I live close to Boulder, and helped another Company, Hybrids-plus, also in Boulder help develop and test drive a Plug-in Hybrid Escape with a 50 mile (city) EV range battery. That 4,000 pound 4x4 SUV would get 150+ MPG in the city duty for the first 50 miles. 90+ MPG highway @ 55MPH for 25 miles.

The Escape battery costs $36,000 for a 50 mile range (12kWh).

I just asked Thursday about making an Insight Pack @ 5kWh.
Cost would be about $18,000 and they would like a commitment for 50 packs before starting.

I'm out of town, but can be in Boulder April 4th.
-John

P.S. The 18k would incl. the 120vAC charger (w/220-240v as an option) and SOC Bar Graph type meter for dash. This would, in all likelyhood be a drop in one-piece replacement. I told them "I gotta guy" who already sells insight battery controllers, but did not mention Mike or MIMA by name. They know me as a Ford expert and were a bit surprised to hear me talking Honda speak all of a sudden.