What about disabling the alternator?

[Supervstech]

What about 300w solar on the roof of a vehicle with 100Ah LFP and a charge setup to feed the starting battery, while on the road...
Maybe better gas mileage with the alternator disconnected?

I wonder what it would take...

 

[gnubie]

Let's see. 10 amps for the ignition system. 6 amps for the AC clutch coil. 15 amps for the cabin vent blower. 10 amps for the myriad control modules. 5 amps for the stereo. More for stuff I haven't even thought about and not forgetting using lights when its dark, ie pulling from the lfp battery so it has to get back in there somehow...

Unless she's an old mechanical pumped diesel better have good shoes for when you have to get out and push

 

[Supervstech]

Yeah, I know... but will it work ya think? It is a mechanical diesel...

 

[gnubie]

Knock off the ignition system and you still have a fair draw to think about but at least the engine wont stop if you wedge the cut off open. 0.3kWh is very little fuel so gain would be marginal really.

When I said mech pumped diesel before I really meant old school, mech fuel pump to bring up from the tank, mech injection, basically no electrics of any kind bar starter, glow plugs and fuel cut off.

 

[Hedges]

If your PV charger is set to a somewhat higher voltage than the alternator, then the alternator should only deliver the extra power needed.

Some wind-tunnel tests may be in order, however, if you think you're going to save fuel.

But how about a wind generator, instead of solar panels? ;^)

 

[Danny]

I have a diesel Yanmar 3gm30. I put an external voltage regulator on my boat. The voltage regulator is programmable and it tells the alternator how hard to work. I have a switch setting that regulates the alternator output when charging lithium batteries.

. However the voltage regulator keeps up with other loads. If the loads are small, the output from the alternator is small. So just turning off loads will save fuel and HP if I need HP powering through seas.

 

[Hedges]

Operating a motor vehicle, the amount of energy lost as heat from the radiator and exhaust is much more than the sunshine on the roof.

A Peltier generator was made for a semi-truck exhaust, about 1 kW I think. Those devices aren't particularly cheap, however, and of course are only being used during the time your engine is running.

My cars will go a few hours during the daytime without a working alternator. Battery is about 40 Ah 12V, so the car consumes about 100W for fuel pump and ignition.

Do you have air conditioning? That would be a couple horsepower so a significant load. How about making an absorption cycle refrigerator?

Gnubie - old school? How about a pony motor and no glow plugs? My old Cats have a magneto, which winds up a spring to snap a good spark when I pull the rope. Spray ether at the intake from a few feet away and it catches. I was disappointed when I realized my K2500 pickup needs electricity for the injectors. And it cooked the "PMD" transistor module, so I relocated it with a heatsink to the only place where it is guaranteed to see airflow any time the engine is running.

 

[gnubie]

Old school considering the amount of electronics wrapped around any new diesel vehicle you can buy these days ...

 

[Supervstech]

I have a turbo diesel suburban.
It currently... has an electronic injection pump and electric injectors... if I power the block heater for an hour it will start So, I can solar power a 400 watt inverter off the shop battery bank...without glow. I can replace the pmd/ds4 with a mechanical pump... I can do without AC several months of the year... but I think using it for a 30minute ride wouldn’t deplete a 100Ah cell... and accumulating energy during the week it sits unused would replenish it...
now... the motor is VERY heat intensive... it has a huge duramax radiator fan, but the clutch releases the fan until the radiator is saturated, or I’m running the ac...

It could be done for my light weekend drives I think.

for that matter, I could tie a bank into the 84 MB turbo diesel with manual, and run that for a few weeks without needing any electricity... not even a starter if I park on a hill, or a ramp.

 

[Supervstech]

Old school considering the amount of electronics wrapped around any new diesel vehicle you can buy these days ...

Heh, my only modern diesel is my 03 sprinter...

 

[gnubie]

Now work out how much diesel it takes to produce 0.3kWh Nice as a tinkering exercise, but not much point if not for tinker time. If fuel saving is the game, lift the foot a wee bit, go a wee bit slower and enjoy the scenery more.

 

[Supervstech]

Now work out how much diesel it takes to produce 0.3kWh Nice as a tinkering exercise, but not much point if not for tinker time. If fuel saving is the game, lift the foot a wee bit, go a wee bit slower and enjoy the scenery more.

Oh, this would ABSOLUTELY be as a tinkering exercise ... thinking of ways to hyper mile a suburban... you know... a 3 ton square block of steel...
I have mine up around 24MPG... keeping the speed below 65 helps a lot... the thing is akin to driving a barn down the road... and adding solar panels to the roof, likely would offset any mileage gained from the exercise...
Still it would be neat to do it, and I’ve never read anyone having done it.

 

[namesgolden]

I'm not sure how much difference it could make. try turning off its control wires (or hooking it to a different battery)

assuming yours has a serp belt it might not be practical to delete the alternator. any fuel savings being destroyed by money spent on the mods.

my MiL has a 1990 square body suburban 2500 with the 454 gasser that exists solely to tow vintage campers in the desert. its in great shape, but if she got an engine swap it would pay for itself in fuel in a few years.