jordan barton wrote:So for the past few weeks I have been pouring through thread after thread on https://ecomodder.com/forum/fuel-economy-mpg-modifications.php
The complete forum can be found here https://ecomodder.com/forum/
Anyways one of the threads which stuck out to me was the alternator delete. This is not so much a "Removal" as it is making the alternator optional. The way I did it on my 1997 Toyota Corolla was by interrupting the IG wire/Field wire. This meant the alternator still had a belt, still was hooked up close to normal. It now meant you can turn your alternator on when you need to. I have a switch mounted in my dash which is convenient to use.
The Idea behind it is to replace your starting battery in your car with one which is a deep cycle battery. These batteries typically can be discharged deeper than starting batteries and they act similarly to a battery found in a off grid system. Now that you have the deep cycle battery installed. You can now start using your car without the alternator being on. You will need to interrupt your field wire. This might also not work for every vehicle and situation.
For me since I drive at most 50 kilometres round trip, I can easily use the car without having the alternator drag on. The hope here is that car MPG will increase. It seems some are seeing as high as 10% gain in MPG. Quite the upgrade.
Now its easy to make it more complicated, its easy to try and introduce a regen braking setup. So the sky is somewhat the limit. I chose to go the simple route and just use a switch. When I see the battery voltage at around 11.8VDC I will turn the alternator on. This is likely to happen when the lights are on and the heater is on.
So when I get home from wherever I was, I now plug my car into a battery charger and charge it up to full.
I could definitely see people living in the city/or those who drive short distances regularly switching to a system like this. It is also easy to go on long trips because all that is needed is to turn the alternator on.
In my instance my old battery was at least 8-10 years old. I will find another use for it. So it made sense to upgrade to the deep cycle battery.
Related threads https://ecomodder.com/forum/showthread.php/test-alternator-vs-no-alternator-10-mpg-gain-98.html
Steve Farmer wrote:do you have difficulty starting the car with a deep cycle batt after running the voltage down to 11.8? or have you always had an opportunity to plug in and recharge?
consider the scenario of an unscheduled engine off eg a police stop just before you get home. it depends on how beefy your batt is but i'd be tempted to keep it above 12.4V both for confidence in starting and longevity of batt.
something to consider is flicking the switch to charge whenever slowing down with engine braking or coasting downhill.