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02-25-2007, 02:59 AM
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#1
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Team GasMisers5!
Join Date: Nov 2006
Posts: 440
Country: United States
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Electric Conversion : Project Bluey
I've got a 1.8 petrol turbo Bluebird (as in my signature), and have so far managed to gain 40% above EPA (and rising steadily). I have thought a lot about the pros/cons of fitting electric drive to this, battery choices, etc. My current plans are as follows:
(1) Use a motor capable of between 4-8kw, with *regen/charge* capability
(2) Use either SAFT Ni-Cd batteries, or Large form factor NiMHs
(3) Motor to be attached to the output shaft of the gearbox.
The above would let me use the electric motor as both engine assist,
and as pure EV mode. Also, I could use regen mode to charge the batteries,
both while going downhill, and when cruising along (the idea being to put the engine into the most efficient range, charging up the batteries, then switch the engine off and drive along on the motor only for a while until the batteries begin to get drained, and start all over again).
I know people will say that regen isn't worth the effort, however, the Prius and Insight both use the ICE to charge the batteries, and get much better
mileages than if they didn't have the hybrid component, and this shows that
regen is valuable in getting better MPG (since this is the *only* way they operate).
The first step is to get hold of a spare gearbox to do the modification too - this has already been sourced. It can then be changed when I change my slipping clutch.
I will keep this thread updated with progress (which will probably start in the late summer, to be honest). There are some things I would like to ask, though:
- Which motor in the 4-8kW range would people recommend (with charging capability?). I don't mind spending a bit more on the motor + control system, but charging ability is very important. I am considering the Lynch motor : http://www.lemcoltd.com/lem_200.htm as it can be 91% efficient at 48V, and it can also charge, and it only weights 11kg (and it is a DC motor)
Note : I could consider a non-regen motor - if I could fit a large alternator or three somewhere else and use that to charge the battery..
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Team GasMisers5 - #1 for first three rounds of the original GS Fuel Economy Challenge
Miles displaced by e-bike since 1 Jan 2008: 62.6 ( 0 kWh used)
Hypomiler
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02-25-2007, 01:17 PM
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#2
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Registered Member
Join Date: Mar 2006
Posts: 612
Country: United States
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Do you want to do a pure electric vehicle, or a plug-in hybrid?
Large form NiMH are unavailable for an affordable price. You can thank Chevron Texaco for that. SAFT makes NiCds, but they are virtually hand-built and rather expensive, around $500/kWh. Unless you have $20,000+ to devote to a pure EV conversion, you're going to be stuck with lead acid of some sort for it.
If you're building a pure EV, 4-8 kW just won't be enough. You'll need at least 20 kW if you want dog slow acceleration and capability to reach highway speeds. If you want 4-cylinder ICE-like performance or better, you'll need at least 60 kW.
If you want ICE-like performance, this gives you two choices: a series-wound DC motor with a MOSFET or IGBT-based controller, or an AC motor and inverter.
For the DC setup, Cafe Electric makes the Zilla controller which can more than fit the bill on performance. Their base model can output over 150 kW, if you have the motor and batteries to use it! Netgain makes 8" and 9" series DC motors that will output a peak of about 130 HP and 160 HP respectively if you maximize their potential with enough battery pack and a controller to output the power they need. A 160 HP DC setup for motor and controller is doable for about $3,500 for those two parts alone, if new. You could have a 40-50 kW system if you use an 8" or 9" motor and pick up a used Curtis controller as well, greatly reducing cost. Series DC motors generally can't do regen braking, unless you're willing to out yourself through a huge hassel to install a second motor for that purpose with very limited usefulness.
For the AC setup, Metric Mind sells a 107 HP motor/inverter combo for about $7,000-8,000. Electroauto.com has smaller AC systems in the 40 kW range for about $5,000. AC systems can do regen braking easily.
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02-25-2007, 03:21 PM
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#3
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Team GasMisers5!
Join Date: Nov 2006
Posts: 440
Country: United States
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I want to make it a hybrid (actually I wanted to change the thread title after I posted it, but I was too late).
Do Chevron hold the UK patent for large form-factor NiMHs?. I found a source in the UK, but, at $1400US per KwH (£700), they are a little expensive. They are 1.2v 100Ah cells. I was considering these, but they were too expensive. I like the sound of those SAFT cells - cheaper then I thought . My inital plan, really, is to use lead-acid batteries for test purposes, and consider alternative battery technology when it become cheaper.
It will be a hybrid electric, noting that the Prius + Insight are also hybrids, and the electric side does help them get good mileages.
The setup I am considering is a Lynch LEM-200 DC motor - it has 88-90% efficiency for generating and providing power - and efficiency can be increased slightly by aligning the brushes. I will use this for 4-5kW of power, which will be enough to give a constant 30-40mph, and will also provide the ability to give nicely prolonged glides / D-FASs on long journeys. Initially, I think just two buttons, maybe on the steering wheel, one for 'charge', and one for 'drive' would be all that is needed, removing the need for expensive control circuitry initially, except for the charging circuitry. I could drive along, and whenever possible, could press the 'charge' button and apply more throttle (putting the engine into a more efficient area of the brake-specific fuel consumption graph), and then, when the conditions allow, cut the engine, and put the motor onto full power, and have a nicely-prolonged FAS / D-FAS. With the poor economy of my car, this would make a huge difference. I could also use the car in pure-EV mode for part of my commuting, if I can get a range of at least 12 miles. All I would do is use the block heater, then drive on the ICE to work, then drive back home (cold engine) using the motors only. This would of course need a controller.
I have already emailed the company that makes the Lynch motor (interestingly they also make a more powerful motor, 40-60kw I think, which would be nice for an EV, but I bet it is much more expensive too!).
__________________
Team GasMisers5 - #1 for first three rounds of the original GS Fuel Economy Challenge
Miles displaced by e-bike since 1 Jan 2008: 62.6 ( 0 kWh used)
Hypomiler
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02-25-2007, 04:55 PM
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#4
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Registered Member
Join Date: Dec 2005
Posts: 4,223
Country: United States
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Neat idea, landspeed.
The ETEK is a similar motor to the one you're describing, I think.
Check http://99mpg.com and click "Mike's Insight". It details his 5th wheel installation with an ETEK and 48v worth of lead acid. He claimed 30 mph and 25+ miles EV range with acceptable acceleration (though his car is very light).
As for regen on the hybrids, most serious ecodrivers will tell you that to get the best mileage in a Prius or Insight, one aims to avoid using regen. Avoid using assist as well. The hybrids deliver the best mileage when using the ICE only and maximizing ICE-off conditions.
Then again, there are times when regen would be useful, not wasteful. EG the house I'm staying at is at the bottom of a hill. Even if I crest the top of the hill with the engine off, coasting at a snail's pace, I'm going too fast by the time I reach the bottom and am forced to brake for the turn. Would be much better to be able to regen that energy into storage.
Interesting ideas. Keep us posted.
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02-25-2007, 05:24 PM
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#5
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Registered Member
Join Date: Jan 2006
Posts: 2,444
Country: United States
Location: Tiverton, RI
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I drove a Prius 2005 a few miles and found that the height of the Newport Bridge was exactly the capacity of the battery so once the top is reached I coast and regen down to the toll booth and fully charged the battery without using any mechanical brakes. That is about the only scenerio that is useful except for the level sections of road when the engine can shut down and run on pure electric but typically the battery runs down faster than it charges up and unless you have a few long hills to go down you only get a little charge from braking to help get you started again but not enough to really notice.
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02-26-2007, 01:22 AM
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#6
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Team GasMisers5!
Join Date: Nov 2006
Posts: 440
Country: United States
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The areas where I would use regen are coasting up to blind junctions, where I need to stop, and down steep hills where I can get 80 mph(!). I probably shouldn't call it 'regen' but the other idea I had was to drive along a level at e.g. 53mph, drafting behind a truck, increase the throttle + put the battery on full charge mode (using the engine in a more efficient mode), and then, whenever there is a slight downhill, to cut the ICE, and use the motor to keep driving. The motorways in the UK are pretty good, but there are always nice downgrades where speed drops off slowly, but fast enough to make the car become noticeably slower than everything else. This is when I would use the motor!.
The other use of the motor would be for a plug-in hybrid electric - I could charge it overnight, then do my commute from / to work, depending on battery capacity, and dramatically improve my MPG that way (maybe even make it use no petrol, if I can get 24 miles out of the battery!). I can drive on wide country roads, and 40 is acceptable (I drive at 35-40 anyway on these roads, and never get any hassle from other drivers, because I always pull over and let them overtake, usually without them even having to slow down (the road is very straight + very quiet). I do of course speed up if there are no overtaking opportunities.
Anyway, I will wait for the pricing from the LEM motor company today, and hopefully it isn't too shocking. Then I can think about how to connect the motor to the output shaft (I could just connect it to the long driveshaft where it comes out of the gearbox, but will have to make sure the car doesn't pull more to one side!). Batteries are looking more likely to be lead-acid batteries to be honest, until something better comes along.
Will keep you posted
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Team GasMisers5 - #1 for first three rounds of the original GS Fuel Economy Challenge
Miles displaced by e-bike since 1 Jan 2008: 62.6 ( 0 kWh used)
Hypomiler
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02-26-2007, 06:59 AM
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#7
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Registered Member
Join Date: Feb 2007
Posts: 11
Country: United States
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I had same idea...
Hi,
I've been toying with the same idea. Though I should point out that I drive an Insight and it is true that you want to avoid using regen or hybrid features to get the most MPG. My goal was to boost the MPG of a convertible Lebaron I was driving last summer. (and test out an idea.) In the end I decided it was a lost cause and sold the car. I still like the idea though.
BTW: I know Mike very well (99mpg.com), love his project, helped him setup the website, etc. I also was able to best his MPG at the Tour De Sol last year in a stock unmodified Insight. The course was over 200 miles so his batteries were drained for more than half of the time. (resulting in hundreds of extra pounds of batteries in the trunk with no motive force.) The etek wasn't set up to use regen and really there isn't that much oportunity to charge them that much. (He basically turned his Insight into a plug-in hybrid.) Assuming you get to charge his batteries for free, he's getting 130mpg. (but he DOES need to plug them in at night.)
However, I really think that you could replace the alternator or AC with a small 6-7HP motor. 6HP is about all you can transfer through the belts...but that is enough to drive my Insight at 50 mph. Attach a potentiometer to the throttle cable so it activates the motor. You could then add a switch to ground the coil to force "stop" the engine at lights, and start the motor again to start the engine.
Regen would be nice - but it adds several hundred dollars of expense (in the controller - and restricts motor choices)...and might be a good second step. The cool thing would be driving around town on battery alone.
As for battery type - I figured I would go with good old Lead Acid. The nice thing is that they are cheap, recyclable, durable (for charging), don't have a memory effect, and don't need special charging temperature checking. The down side is that they would be 50% heavier. On the other hand, you only get to use half of the battery capacity in an Insight or Prius due to the battery management system. The Lead Acid could be used much deeper. I think it actually balances out. Besides, my design had 200 lbs of battery, so it's like just an extra passenger.
As for voltage, I wanted to go lower like 24-48 Volts. It is safer, uses less connectors (cost), and the chargers and motors tend to be less expensive.
What do you think? I would happy to give suggestions...I made a purchase list of parts from www.evparts.com, but never bought them.
-John
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John Waiveris - www.invisiblegold.com - www.waiveris.com
2001 Honda Insight 5sp
66 Lifetime MPG
84MPG 1000 miles GA to CT (one tank)
Tour De Sol 2006 - 93.7 mpg day 1 - 80.1 mpg day 2
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02-26-2007, 07:06 AM
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#8
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Registered Member
Join Date: Dec 2005
Posts: 4,223
Country: United States
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FYI, for thost just joining this thread, there's a similar one (not specifically related to landspeed's car) here:
Low cost AC drive motor / homebuilt hybrid retrofit
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