[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.