Adding regenerative braking to the Mirage - Page 4 - Fuel Economy, Hypermiling, EcoModding News and Forum

Piotrsko · 09-04-2019, 11:14 AM

Not to be annoying, but that looks low for consumption. Given my stance on cheap chinese electronics, can you do comparisons with semi calibrated equipment?

Daox · 09-04-2019, 02:25 PM

The only other gauge I have is a regular analog 200A ammeter or 10A multimeter ammeter. I'm not sure how I can use either of those to verify accuracy. Ideas are welcome.

Daox · 09-04-2019, 03:12 PM

I agree that the usage seems very low. However, running rough numbers the gauge doesn't sound horribly far off. My average commute is about 25-30 minutes. So lets say:

The engine is on for 2/3 and off for 1/3.
Power usage is 6.5A with the engine on, engine off is 2A.

Engine on power usage is 6.5A * .33 hours = 2.15Ah
Engine off power usage is 2A * .17 hours = .33Ah
Total power usage = 2.48 Ah

Sounds reasonably close to me.

Daox · 09-05-2019, 09:30 AM

Today's commute in was quite idea. Lots of EOC. I did use the fan on low (3.5A draw) for about 2/3rds of the trip for some heat. I got to work with about 4Ah used. So my really rough guess is I regenerated about .5 Ah of that. This is really rough guestimation though.

The trip home has more opportunities to use regen because of the placement of stop lights and signs at bottoms of hills. I sure hope I can get more than .5 Ah out of regen hahaha. But, I will do my best to verify it.

Piotrsko · 09-05-2019, 11:12 AM

If your 10 amp is fused and you have spares, use that. Your load is supposedly lower than 10 amps. Or you can use a known hot resistance from a vehicle lightbulb and measure what the current through that bulb is after going through the shunt.

Daox · 09-06-2019, 06:38 PM

I've been looking around and I found another gauge that I am going to pick up instead of the one I have. It doesn't have as many gauges, but I think it will work a lot better. It specifically says that it measures current in both directions and adds and subtracts from Ah used.

DROK DC 0-300V 200A STN LCD Display Digital Multimeter Voltage Ampere Power Energy Ammeter Voltmeter Battery Volt Amp Meter AH Monitor Panel with Hall Sensor

teoman · 09-07-2019, 12:39 PM

4Ah * 12v = 48 Wh

1 liter of fuel is 40 MJ = 11kwh
If we assume terrible IC and alternator efficiency that is 1kWh of electricity produced.

So you saved 0.048 liters of fuel.

In roughly 20 days (or a work month) you save a liter of fuel.

teoman · 09-07-2019, 06:49 PM

You have any mpg numbers yet?

Daox · 09-08-2019, 11:14 AM

I haven't done any mpg testing on the mod yet. I honestly haven't planned to do it either. A bunch of people have done it over the years. Check the wiki link below.

Car MPG Efficiency Modifications Main

teoman · 09-09-2019, 01:21 PM

Yep. I have already been over those many times. They say more numbers tests required