Alternator delete - a huge fuel saving potential?

[sser2]

I am working on a project to eliminate belt-driven accessories in Geo Metro to further improve fuel efficiency. The car has a 60 A alternator. Alternator voltage output is 14 V. With all accessories on, electricity consumption may be as high as 40-50 A, or close to rated output. Electric power output could be 1.1 hp, and with 60% energy losses typical for a smaller alternator, power taken from engine for electricity generation is almost 3 hp.

With Metro's engine rated power of 56 hp, one might think 3 hp is no big deal. But 56 hp is rated power at 6,000 rpm. In everyday driving, real engine speeds are around 2,500 rpm, with maximum power output at this speed of only 27 hp. This means that alternator may rob 10% of engine power when climbing a hill at full throttle. At sustained economical highway speed of 55 - 60 mph, engine power may be as little as 6-8 hp. Under these conditions, the alternator may consume as much as 1/3 of engine's power output.

Seems like not only a huge fuel savings potential, but some improvement of dynamics of this generally anemic car.

[oil pan 4]

Yeah there are posts on here where members have done alt deletes on metro and other small cars.
Fuel economy increases by up to 10% if I remember correctly.

[sser2]

I have read some of the posts about feasibility of alternator delete, but I am looking for a practical thing rather than a trial.

The idea is to reduce current consumption to 10 A and use a 100 ah Li-ion battery to allow a minimum 10 hour run time.
- 1A fuel pump
- 2A ECU, CDI ignition, relays and solenoids
- 1.5A electric water pump
- 3A LED lights including headlights

200 F super capacitor for engine starter. 80 A charger should charge battery in a bit over 1 hour.

[oil pan 4]

I have a 60ah lithium battery and it starts my V8 diesel engine just fine.
A starting capacity is unneeded.

[sser2]

What is your battery? Mine is made out of 18650 cells from recycled computer batteries, which are not high current type. Current wise, this battery should be capable of supplying 100 A for Metro's starter, but my Li ion battery goes under seats, which will require long thick cable from battery to starter. With supercapacitor under hood in battery tray, car's existing starter harness can be used.

[Gasoline Fumes]

I ran my Civic all last summer without the alternator. I'm only using it now because I need the extra power for the heater blower. Two deep-cycle marine batteries behind the front seats and almost all lights converted to LED. I do notice an increase in very low RPM power without the alternator.

Originally Posted by sser2

But 56 hp is rated power at 6,000 rpm.

55 HP @ 5700 RPM.

[oil pan 4]

My battery is made out of amp20 LiFePO4 cells.

I hear super capacitors don't like engine compartment heat.

[oldtamiyaphile]

Originally Posted by oil pan 4

I hear super capacitors don't like engine compartment heat.

I've got four years on mine and haven't taken any special precautions- they just sit next to the battery in a small plastic container.

[California98Civic]

I have had success with this.

[cRiPpLe_rOoStEr]

I wouldn't feel so comfortable in a vehicle without any sort of genertor, be it an alternator or a motorcycle-type stator (that could also eventually replace both the alternator and the distributor). Nowadays it might be worth to consider a BAS-Hybrid retrofit.