Bitcoin Forum

Just for the fun of it I imagined putting this mining rig in the trunk of my car:

1) Extra car battery
2) Raspberry Pi
3) An amp-meter that turns on the power when sufficient watts are available
4) A bitcoin mining rig that isn't worth powering at current power costs

= When enough excess power is available the rig is powered on and you mine for free.... In your car!

But then the obvious point hit me: Only terribly inefficient car generators would generate enough extra power to actually get any mining done :(

No matter how you turn it around, this would lead to extra gas costs right?

Obviously

- you could also drive more economical and just use the saved money to pay for your electric.

Also your alternator has the potential to put out about 100+ amps at 14.4 volts

Just plug it into the socket of your wall... If it generates any extra, then you should sell your car anyway, Highly inefficient.

Bad idea  ???

It's a freaking awesome idea!  :D

...as long as awesomeness is your only goal.  8)

Hrm...  so what would be the $/kWh on that?   I mean, if I'm going to drive to work every day anyway...

$4/gallon.  36MPG.  Average speed across entire commute of 46MPH.  35 mile comnmute.  12V through a 10A fuse...

4.000   dollar   per gallon
36.000   miles   per gallon
0.111   dollars   per mile
35.000   miles   per commute
3.889   dollars   per commute
      
46.000   miles   per hour
35.000   miles   per commute
0.761   hours   per commute
      
0.120   kWatts   per hour
0.091   kWh   per commute
      
42.59   dollars   kWh

edited for bad math.  Also, Q.Q

FOr the hell of it I did this with a RPI a USB miner and internet through my cellphone a while back.

LAWS OF THERMODYNAMICS = there is no free power!

You will be burning more gas/petrol to power it.

Unless that power is already being generated by your alternator and wasted.  Then mining with the excess makes you more efficient.  <.<  

I like the idea of an automotive-based hotspot network utilized by mining hardware.

This is a fallacy. A car with it's air conditioning on consumes more fuel than one with it off.

except any real excess power you generate isn't going to be able to power a mining rig + by mining on the rig in the first place you increase the load on the alternator which increases its resistance, which makes the engine have to work harder, which makes you burn more gas.

It isn't going to be free, but when it comes down to it, if its some USB miners and an RPI you probably aren't going to notice the little bit of extra gas they'll run you.

What were you planning on doing for network? Just wifi + hotspot on your phone?

I thought that was because engaging the air conditioning compressor adds a load to the belt system that was not there with the compressor off.  Likewise, I thought the alternator was always engaged, to provide system power and keep the battery charged.  Perhaps I'm mistaken.  

The more power you demand from the alternator the harder the engine works to turn it.
It's like a dynamo on a push bike, the harder you pedal, the more power you generate, and the brighter your lights get.

Oh, I didn't have a plan.  I've written this all off once my math said $43/kWh.  I was just enjoying the scifi aspect of an army of 4G enabled cars with a little mesh network for mining.  I also hadn't considered the resistance increase on the alternator.

How else should one pay off his Pagani?

Cool idea, never thought of that before.  :)

An alternator produces UP TO ~100A.. meaning it doesn't continuously put out 100 amps when the alternator is spinning.  If it did, assuming it's 75% efficient, you'd be drawing 100A/0.75 * 14.4V = 1920W @ 746W/HP = 2.57 horsepower your engine is putting out that isn't going to motion of the car.

Cars are about 35% efficient - 30% in heat removed by internal cooling and the rest out the tail pipe (why turbos are wonderful)
1 gallon of gas contains 131,760,000 Joules - @ 35% efficiency, you get 46,116,000 Joules of energy out of.
46MJ ~ 12.81 kWh.

@ $4/gallon, 1 kWh costs $0.31/kWh

Also don't forget to apply alternator efficiency on top of that too. => $0.31/0.75 = $0.41/kWh

YMMV

edit - was mistaken, disregard.  find posted SPOBI quoted further down in thread.

::walkofshame::

"In-car mining rig - bad idea right? "

Right.

My $.02.

;)

I'm just trying to figure out why it would be  necessary

how do you get internet into cart  http://static3.wikia.nocookie.net/__cb20130627202335/athfwiki/images/9/94/Danger_cart.jpg

ALSO.  why not just plug a block erupter into work computer.  can't possibly use THAT much power??

Necessary?  Entirely unnecessary.  Amusing though.

The irritating part would be lugging the mining rig back and forth between your car and your work/home each day.  After all, there's no good reason to leave mining equipment idle when you're not commuting.

Another angle on this...  even if we assume that the alternator usage doesn't increase fuel usage, we should probably take into account effort vs return.  At $0.15 per kWh, commuting an hour each way to work, assuming 120W power provided for free by the car, that's still only $12 a month in power savings.

So, yeah... mostly a for fun thing.  Unles you're a truck driver and you don't want to leave your mining equipment running at home while you're on the road.

I think it's all been covered :) Thanks guys!

Pros:
Coolness factor

Cons:
There is no such thing as free power - something or someone always pays :-) Cruising RPM would simply be higher :)

And since someone asked: yeah - 3G/4G internet from my phone or a USB-4g-router.

I still might do it though :-)

Dunno - I hear about mining rigs setting on fire quite frequently, can you imagine the memes if a car exploded whilst mining dogecoin

I think a cool way to do it, is to put the rig in your work place. Hide it some where, then it will be free power. If your work find it, just don't admit it is yours.  :P

I know 3 GPUs of mine already caught on fire. Lucky it is under warranty. 

Is that blinking light an anti-theft device or a USB miner? Green...must be a miner.

And was that in your workplace?  ;D

Nope. That's not at all how alternators work. There's no "extra" power -- the voltage regulator found in every single alternator-equipped car is varying the excitation current in the brushes of the alternator in order to get a relatively constant charge at the battery terminals. The more load you draw, the harder the alternator will have to work to replace that load, all under control of the voltage regulator.

For instance, drag racers -- who are trying to eke out fractions of a second over their competitors -- use techniques such as electric water pumps and electric cooling fans that they can turn off for the duration of a run (less than 10 seconds, generally) and then turn back on again to cool down the engine once the run is complete. They don't do that for shits and giggles, they do it because it reduces the load on the engine, which allows them to deliver more power to the wheels.

(And in serious drag racing -- well above the hobby racer level -- I wouldn't be surprised if they did away with the alternator altogether and just used a battery).

semi drivers who are never home and want to play around with bitcoin mining hardware in their cabs ? While sitting at truck stops.

when do you have to be home to watch a bitcoin miner? I went on a work trip for over a month and didnt give my rig a 2nd thought ..

that aside wouldnt it just be cheaper to buy a generator and use fuel ?

You are COMPLETELY wrong. Look it up.

Whoops, wrong assumptions made by me.

Researched, error noted.  edited original post and stupidity quoted above for posterity.

I doubt a generator could provide power cheaper than the electric company.  I know this one company I worked at had to use a big deisel generator for a while and the cost was something like 5k a month rent and close to 20K a month in fuel.  Something like 700 gallons a week to provide 150KW/208V service 24/7.  That'd be enough to run ~120 KnC Jupiters at ~600 GH each or 72TH.  ~16.5BTC/day at current difficulty, but at a cost of ~1BTC per day.