Alternator delete

[Cobb]

Sounds like you got more rolling and or aero resistance to over come the benefit from the alt delete.

Originally Posted by paintme205

Mileage on last tank was 43 MPG. I was driving 75-80 the whole time and there was 40-50 MPH winds and it was cold (45 degrees) but still figured I would get better then that.

[Xist]

Strange. I posted a response, but it seems to have disappeared.

Isn't an alternator delete considered to be a 10% gain? In order to not see improvement, wouldn't you need to increase the mass of the car by twenty percent, presumably with batteries?

That is the only way that I could imagine an alternator delete not showing an improvement, while there are many variables with boat tails. It would be good to have specific results for the alternator delete, but I think there are far more ways that a boat tail could be inefficient.

[oldtamiyaphile]

Originally Posted by paintme205

I bought a pulley from tractor supply and rigged it up so that I can still run a belt without the alternator pulley being used.

If you still need a pulley to make the rest of the car work, I'd rather leave the alt and connect a kill switch to engage the alt under braking. Ideally under DFCO too but that requires more effort.

[Hypermiler1995]

Any way to set up a DIY regenerative brake system to charge the battery instead of the alternator? This would cut out the extra batteries, and use otherwise lost energy.

[California98Civic]

Originally Posted by oldtamiyaphile

If you still need a pulley to make the rest of the car work, I'd rather leave the alt and connect a kill switch to engage the alt under braking. Ideally under DFCO too but that requires more effort.

This is what I do with my alternator kill switch. On a good long downhill or breaking situation, I bump start, put it in gear, watch the O2 sensor reading, and flip on the alternator. No fuel burned, power generated, and I have a kind of crude regenerative breaking. Inferior to the real deal regenerative systems, but wicked cheap!

[oldtamiyaphile]

Originally Posted by Hypermiler1995

Any way to set up a DIY regenerative brake system to charge the battery instead of the alternator? This would cut out the extra batteries, and use otherwise lost energy.

The alt should run at high output if it sees low voltage, so this is a reasonable kind of regen braking (most new cars do this). You could shoe horn in a really big alt for greater effect, possibly with a supercap bank to capture as much energy as possible.

[Cobb]

Depending on the room under your hood you could mount multiple alts and switch them with the brake petal as long as you engine brake. Then you just need a battery to take the sudden inflow of lighting.

[brucepick]

Nice project.

I did a similar project on my Civic (RIP) and then transferred the batteries and switches over to my Accord. My commute is just over an hour each way, with a lunch or errand run often added. So I need about three hours' capacity for daily use.

I use two dual purpose marine batteries, in parallel. Those total about 160 AH. And a 40AH lithium pack. The lead-acids are wired to power the headlights and all fans. Everything else runs on the lithiuum pack. Oh yes - a regular starting battery runs only the starter. It easily goes several days between chargings; starting alone is not very taxing.

Running the car without headlights or other major draw seems to be about 10-15A. Headlights, about 15A. Small corner lights alone, about 5A. Various fans, about 5-15A each.

Here's something I did that I like a lot. It boosts the lead acid circuit's voltage by 1.2V. Under heavy load it still boosts it by 1V.

I wired 8 NiMH D cells in parallel. They are 1.2V and 10,000 mAH each, or 10AH. So the pack paralleled is 80AH, 1.2V. They have solder tabs and I used pretty heavy wiring to support heavy current draw. That pack is put in series with the lead acid cells. The headlights and fans run much better on the resulting 13-13.6V than on just the lead acids at about 12-12.5V. For charging purposes, a quick connect harness wires the eight cells in series so a fairly common NiMH charger can do that job well.