Plug-In Hybrid Retrofit Kit Using Alternator as Motor

[ECA Systems]

I would like to thank everyone for your comments.

The first battery that was used in the "Alpha Prototype" consisted of (12) 6S 5000mah LiPoly Turnigy Batteries configured with 4 cells in series and then 3 of these quad cell packs in parrallel resulting in 15Ah at about 100Volts. I later increased that voltage to about 110volts buy adding (3) 2S 35000mah LiPoly packs to get higher top assist speed. This 15Ah pack lasted about 12-13 minutes and was used for the extended test shown on the website. On the demo I have purchased (8) 115ah deep cycle lead acid batteries because I wanted to have a much longer assist time to be able to tweak the system on my daily commutes. Considering these batteries are lead acid I expect about 40-45 minutes from the battery pack or about a 3 fold increase in assist time. I know the weight is a problem but I don't have the $2500 to invest in a pack of 40Ah LifePO4 batteries, BMS, and charger. I am funding this intirely myself so I am trying to keep cost low even though the lithium batteries are the best choice. Consequently I have intentionally not put too much emphasis on the battery system since this is not one of the key elements unique to this conversion method and would be required no matter how the vehicle was converted.

Some one was asking about how the top speed is limited and what limits top speed is the battery voltage. Through my testing unloaded I can get 12K rpm+ but once the motor is under a load at 100vdc I can only get about 6500rpm before the motor can no longer generate enough torque to effectively assist the engine. On the prototype the ratio between the crank pulley and the alternator pulley was about 3 to one. This resulted in a maximum engine rpm of about 2200rpm which is directly related to the maximum speed. Like any other motor the effective assist RPM varies fairly linearly with Voltage. Right now the speed control I am using is limited to 120Vdc absolute max but I keep it under 110vdc.

For the first poster I will definately need some assistance in the future getting this on more varied test vehicles. Join the mailing list and I will definately keep it in mind.

The totally automated system was tested on the Mazda CX-7 this summer and it worked well but I had all of the components spread out on the floorboard because I was really just prooving the concept. I have since removed everything from the vehicle because I was constructing the extended test and demo vehicle.

I know there were also some comments about temperature rise on the alternator. The two videos on the website were actually produced when I was working ReGo Electric's electrical engineer. The extend test was done at highway speeds as well as around town and this was not the only test conducted just the only one fully recorded on video. The alternator stator coil temperature rises to about 200F and stays there. Yes I had to install a 3" fresh air duct to direct air into the area of the alternator because without it the alternator could only be run in cycles with 3 minutes on and 2 minutes off. The second video was recorded a while later because he wanted to see what temperatures the alternator normally sees. So I plugged the cool air duct I had installed and drove the vehicle around to see what temperature the alternator would normally run at. Of course at slower speeds or when sitting in traffic the alternator gets much hotter than driving at 65mph but the only time the assist is active is when the vehicle is moving and air in flowing. I have documentation from alternator stator wire manufacturers and motor manufacturers, toshont.com/ag/mtrldesign/AG05%20(Temperature%20Rise).pdf, that state that 200F is well within normal operating limits for 20,000 hours.

One person asked about gains in mpg. These are documented in full on the "Historical" video sections of the website. On the Alpha prototype with a limited assist range of 40-60mph I saw increases of about 65% at lower speeds 40-45 (~44 unassisted, >70 assisted). The gains decrease as speed increases but this is expected. I also found when I ploted the gains that even though the mpg increases were smaller at higher speeds your traveling faster so you cover more distance in the same amount of time so the actual fuel conservation is pretty close to the same.

I am a mechanical engineer by profession and have done my best to make all of my testing objective and did my due dilegence in research.

Please keep the comments coming. If I have missed any questions let me know. I check the forum posts once a day.

[kyerik]

Is there any regenerative braking? If not, it seems like you could attain this on a vehicle with a manual transmission with a little programming of the ECA control unit.

I can see that instantaneous mpg would be better with your system when the assist was working, but wouldn't mpg at low load decrease? (because extra power is needed to charge the batteries).

I would like to see some blind testing. Many persons can get 10-20% over EPA ratings by driving an unmodified vehicle with economy in mind. How about placing a cover over the ECA display and have a 3rd party turn the device on or off for a whole tank- then the tank mpg could be posted on a website as tank 1, 2, 3... Then the 3rd party reveals which tanks had the ECA on and which tanks had the ECA unplugged.

[Cobb]

I am open to testing it on either of my vehicles.

Before you do too much you would need to see a break down of cost over mpg improvement or over all drivability and how much driving it would take to recoup your investment.

Make sure if you go the lifepo4 route that you have one hell of a bms or procedure to keep the cells in check. 45 minute run time with your current pack would do a leg of my trip, then I hope its small enough to take in the office and plug in under my desk.

As a Enginer PHEV owner Ive read many people talk how the bms ruin vs helped their cells and the benefits or gains was all over the place depending on the nut behind the wheel, setttings used and wait time to get replacement or service.

BTW, those are 48 volt system if you choose to offer this as another option for the IMA guys.

[cRiPpLe_rOoStEr]

I remember some years ago Bosch was working on a single-unit starter-alternator setup, which would be a good option to ease the integration with a regenerative braking setup.

[ECA Systems]

Again, thanks for your continued comments and questions.

The system has no regeration capability and is purely plug-in on the high voltage hybrid assist side. The vehicle may have additional load put on the engine when the vehicle switches back to 12V charge mode to replenish the capacity used by the vehicle's headlights, wipers, a/c, ignition and other electrical loads while the system is in assist mode. Essentially you're just carrying around electrical storage instead of a quanitity of fuel in the gas tank. Once the battery is depleated the system is suspended until the battery is charged.

As far as the fuel economy gains reported on the Website and on the youtube video they are totally correct and genuine. If you view the entirety of the gains video in the "Historical" video section of the website, the first two clips show fulll length videos of exactly how the MPG gains were recorded. The vehicle's cruise control was set and then the average mpg was reset on the OEM display. The average MPG display in the Mazda CX-7 samples for 60 seconds before displaying the average result. In all of the tests, the vehicle's cruise control was controlling the speed at all times and the vehicle was traveling the same direction over the same stretch of road at the same time of day. I felt this was sufficient to yield accurate results.

Also, I have done several studies on the total cost comparison between stock and using the assist system including all components, expected battery life and electricity consumption. These results can vary greatly between drivers due to many factors so I designed a device, several months ago, that can be plugged into a perspective customers OBDii port that will estimate the % gain in fuel economy and the % reduction in fuel cost they can reasonably expect given their normal driving habits. This device will also be able to estimate the battery size they will need since it is based on the same algorithms that the actual system is and can determine when and for how long the assist system would be active and at what speeds. I am really doing everything I can to make sure perspective customers will have an accurate estimation of gains so they can make an informed decision. If you do a lot of stop and go driving and sitting in traffic the retrofit kit may not be very effective, however is you drive longer distances at fairly stable speeds this system can be very effective as reducing fuel consumption.

As for blind testing, I have always intened to conduct field testing with independant drivers. After I get the Demo/Extended test vehicle completed in the next several weeks and get a month or so road time, I will consider recruiting a few trustworthy interested parties form this forum and others to carryout independant testing and report results and document problems. If you may be interested in doing this send me an email through my website or this forum expressing that you would like to take part in field testing. You will need to have the ability to convert your alternator and purchase and assemble the components yourself and the conversion vehicle preferably needs to have an OEM mpg display for credibility (My 2004 Ford Taurus has an average mpg display built in to the instrument cluster and the 2011 CX-7 had both Instant and Average displays). I will supply instructions, a bill of materials with suppliers, software and consulting in exchange for full rights to your test results and signing of confidentiality agreements. Don't worry, all of the current components used in the system are off the shelf with only minor electrical assembly and soldering.

[Cobb]

Over all I think this will perform best with the pulse and glide technique.

Second, upgrading your starter battery to a deep cycle one.

[ps2fixer]

Originally Posted by Cobb

Over all I think this will perform best with the pulse and glide technique.

Second, upgrading your starter battery to a deep cycle one.

I agree, but I don't think the OP is aware of all of our tricks to get "crazy" mileage .

Maybe he would be interested in looking at different "modes" for assist and add regen abilities. Only down side I can even see to this, is the belts might wear out much faster since it is being stressed more.

I wonder how efficient the alt is at producing power vs using the power to make something move. I would suspect if going from mechanical to battery storage back to mechanical again is over 30%, it would work well with P&G since from my understanding, a ICE engine is only 20-25% efficient from fuel to movement.

I personally would think for the ecomodder members would like 2 button manual control/override as an option. First button to enable assist (don't matter what the system sees), and the second to reverse the effect and regen back to the batteries. In the correct hands, it should give amazing results!

[ECA Systems]

Thanks again for all the comments. Infact the last iteration of the alpha prototype was a two button system. One for assist and one for cancel. The driver sets the cruise and then presses the assist button. Within one second, the assist system is applying 65-75 amps at 100 Volts. Anytime the brake is depressed or the driver presses cancel, the system cancels and returns to charge mode. This is alot less complicated and didn't rely on collecting vehicle data. I just didn't think the majority of regular drivers would want that level of interaction. I do agree that this tool in conjunction with hypermiling techniques could yield great results. I will defiinately keep this version part of the line up.

[brucepick]

Originally Posted by ECA Systems

... Anytime the brake is depressed or the driver presses cancel, the system cancels and returns to charge mode...

I've read elsewhere in this thread that the system does not provide regen. True, in that it does not provide the "strong" braking regen of a full fledged hybrid. However keep in mind that various conditions will charge the battery pack. I estimate that in stop and go driving the gains will be pretty good, especially on the hands of a skilled hypermiler.

On the open road on the other hand, I estimate that charging would mostly (only?) be accomplished by having the engine power the converted alternator. I think that for good gains on the highway it would be good to pre-charge the battery off a/c wall current to get the max possible assist time. But then the system has an upper speed limit for assist so high speed operation isn't yet it's forte. Possibly increasing the pack voltage by about 20% would raise that limit to a higher speed.

[night9]

I would like to see before and after fuel logs to substantiate the benefits on mpg for the test vehicle. I think It would certainly help your case for the benefit of your system. People want solid A-B-A testing to prove it works well and also that it can do it over and over again on an everyday basis. Not just on a single trip in certain conditions.

Otherwise the system looks really promising. I love the idea. I think it could really help my car's gas milage.

Thanks,

Areen