Can a semi truck support a desktop computer?

[Carrotslayer]

That time when you find out every question your friend asks he then goes and asks a forum to test you

[Carrotslayer]

17 hours ago, Genwyn said:

Lot of truck drivers on this forum

im a cretard who sunk hundreds of dollars into customizing a company owned truck

 

tldr is that there's this never ending list of problems with running a desktop on a truck, the biggest of course being powering it but other ones such as vibration and airflow come into play

depending where you put it in the cab the desktop may just function as an expensive air heater, you'd be surprised how quickly heat will build up in a small cab, it has to be somewhere out and open, not in a cabinet 

 

vibration and general road impact will destroy most desktop hard drives if they're not soft mounted, I speak from experience, even some laptop drives have a bad time if left on while the truck is moving, more than once the drive protection on my latitude e6410 would kick in and lock the drive 

A vertical pc orientation is not recommended as any heavy gpu could quickly snap a pcie slot, also speaking from experience. Horizontal HTPC cases are the best for this kind of thing as they also have a lot of mounting points.

 

High wattage components in general aren't recommended unless you're running a decent apu. In the same sense that a large inverter can power a microwave, it doesn't mean you should power a microwave on an inverter alone. The trucks batteries just aren't meant for that.

And as others have mentioned, pure sine is a must.

 

I suggest a laptop

 

On the point of breaking the PCI slot. Do you think a support on the underside as well as on the side would help this matter? That has been my concern from the start. UPHERE  makes some supports for video cards that i will try to edit this post with links.

https://www.amazon.com/upHere-Graphics-Anodized-Aerospace-Aluminum/dp/B076GYL25H/ref=sr_1_1_sspa?crid=33YKJNE8KP0W6&keywords=video+card+support+brace&qid=1565186209&s=gateway&sprefix=video+card+suppoort%2Caps%2C140&sr=8-1-spons&psc=1

 

https://www.amazon.com/upHere-Graphics-Anodized-Aerospace-Aluminum/dp/B079HSVSLR/ref=sr_1_2_sspa?crid=33YKJNE8KP0W6&keywords=video+card+support+brace&qid=1565186268&s=gateway&sprefix=video+card+suppoort%2Caps%2C140&sr=8-2-spons&psc=1

Edited August 7, 2019 by Carrotslayer
Added Links to products mentioned

[Votivee]

13 minutes ago, Carrotslayer said:

On the point of breaking the PCI slot. Do you think a support on the underside as well as on the side would help this matter? That has been my concern from the start. UPHERE  makes some supports for video cards that i will try to edit this post with links.

https://www.amazon.com/upHere-Graphics-Anodized-Aerospace-Aluminum/dp/B076GYL25H/ref=sr_1_1_sspa?crid=33YKJNE8KP0W6&keywords=video+card+support+brace&qid=1565186209&s=gateway&sprefix=video+card+suppoort%2Caps%2C140&sr=8-1-spons&psc=1

 

https://www.amazon.com/upHere-Graphics-Anodized-Aerospace-Aluminum/dp/B079HSVSLR/ref=sr_1_2_sspa?crid=33YKJNE8KP0W6&keywords=video+card+support+brace&qid=1565186268&s=gateway&sprefix=video+card+suppoort%2Caps%2C140&sr=8-2-spons&psc=1

I would either get a case that you can lay on it's side or buy a case with a vertical GPU mount and a PCI-riser cable. If you use a riser there should be zero strain on the board.

[dizmo]

It honestly sounds like you're going to have to do way too much to get the desktop to work; likely more than an even more powerful laptop would cost.

Just get a laptop. A desktop in the truck simply doesn't make sense.

[Emanbaird]

18 hours ago, Zusafek said:

As a truck driver I can say that you will drain your batteries pretty quick on the truck. My laptop can be on gaming and working on battery from the truck for about 7 hours before it goes into low power mode to protect the truck batteries. And that's a laptop pulling 170 watts only. 

+1 to this, laptops probably gonna be the best you can get. I was looking into this kind of stuff for an RV and it basically comes down to unless you can get auxiliary power from like a truck stop or like an actually outlet you are pretty SOL for a desktop

[greenhorn]

Ok, so in essence you would take a DC voltage from the vehicle's battery, convert that to AC (preferably pure sine wave) using the inverter and feed that to the computer's PSU that converts it back into DC (and steps it up/down to the different DC voltages needed).

I would try using an external 12V or 24V battery in connection with a computer PSU that accepts DC input. With a little bit of tinkering, you should be able to make it work (don't forget appropriate safety measures) without the risk of draining the vehicle's battery too much.
That special PSU with DC input might be hard to find and be a bit more expensive though, depending on where you live.

If you still want to go with a regular PSU and an inverter, I would still recommend trying it with an external battery and a pure sine-wave inverter first before you start tinkering with the vehicle.

[Carrotslayer]

So we are looking into the APC 1500ms. It is PureSine and 900W. 

https://www.apc.com/shop/us/en/products/Back-UPS-PRO-BR-1500VA-SineWave-10-Outlets-2-USB-Charging-Ports-AVR-LCD-interface/P-BR1500MS

 

Would using this remedy the power issue and make this feasible?

[mariushm]

The easiest solution would be to buy an on-line UPS - it's an UPS that always powers the devices attached to it from the internal battery and only uses the incoming "dirty" power to top up the internal batteries.

 

If the truck doesn't have a generator, you should be careful about discharging the truck batteries and about the fuel amount you're gonna consume by idling the truck. Keep in mind some companies monitor the amount of time trucks idle and the driver may get fined if the truck idles too long - some trucks are even "programmed" to shut down engine after something like 20-30 minutes of idle time.

 

The truck batteries are "optimized" for cranking, for starting up the engine, they can give bursts of high current (like 50-100A, maybe more) for a few seconds in order to start the engine, but they're not so good at constant long term discharge... ex let's say the truck has 2 x 12v in series for 24v and your PC consumes 500w ... you're looking at a constant discharge of 500w / 24v = 20A ... the batteries would probably be discharged within 20 minutes if the alternator and engine aren't working to top them up.

 

Your best options are probably to get some high capacity VRLA (ups style) batteries (which are optimized for continuous discharge) and a small charger and have the batteries charge as you drive your truck down the road - the alternator will top up the batteries and will probably have excess energy it could pump into those UPS style batteries.

Then, you could power the inverter or whatever from those VRLA batteries.

Still, continuous 500-600w consumed by your PC is a lot of wattage.

 

Just want to make sure you're not confusing capability of a power supply with actual power consumption of a PC... you could have a 1000w power supply but if your PC's components only need 100w, then the power supply will most likely only take around 110-120w from the AC input (10-20% are lost due to conversion inside the power supply).

Keep in mind that inverters are also around 85-90% efficient, so to give 500w to a PC, your inverter will probably consume 520-550w from a battery or some source...

 

[Pixel5]

i really dont know why people here are talking so much about a UPS and pure sine wave bullshit.

this only really matters if you have electronics that directly use AC power or you run AC motors as they rely on the sine wave.

 

The PC powersupply will as one of the first steps right after a step down via a transformer convert the whole AC power to DC via a full bridge rectifier and these dont care if its a modified since wave or not.

 

after that its all DCand nobody cares about where the sine came from or if it even was a real one.

[mariushm]

@Pixel5  a modern power supply will have input filtering, a bridge rectifier to convert AC to DC and then an active PFC circuit which boosts the input voltage from whatever to around 400-420v DC. From that point, the power supply sends varying amount of pulses of that 400-420v DC through the psu high frequency transformer to create 12v, 5v and 3.3v.

 

Some power supplies have an Active PFC circuit which "expects" relatively sinusoidal AC input and can have a hard time boosting the shitty AC voltage that's simulated sine wave with periods of zero volts on the input to the high DC voltage - especially at high outputs like 500-600 watts the PFC of a power supply can be "stressed"  by the crappy AC input.

Basically the mosfets or the diodes in the Active PFC circuit can overheat and break down in extreme cases.

 

So, you would most likely have to derate the power supply and most likely you'll also get a lower efficiency power supply if your AC input is not pure sinewave.

It's not a problem if the computer uses 100-200w and you have a 500w+ power supply, but the guy says a PC that consumes up to 500-600w

Also, consider that the primary capacitors only hold enough charge to power the psu for around 8-12ms ... they're supposed to hold enough charge for 1 cycle (1 / 60 Hz = ~16ms) but in reality it's not that. At high output like 5-600w , these primary capacitors may not get a chance to fill up with that much energy if the input AC is crap and the active PFC circuit can't keep up and fill them ,,.. now imagine the scenario where the engine dies or something happens and the truck's battery drops to 10-11v for a few seconds and the inverter has a "hiccup" of a few ms ... your system may reset/shut down.

 

[Dedayog]

If we are talking about a long haul big rig then you're pretty much just going to plug in the SFF desktop in the sleeper section and wall mount the monitor?

 

These things are powered like small studio apartments.

 

Tho this pic shows a laptop, you have the room for a desktop setup if you get creative.

 

https://www.kenworth.com/media/9834/kenworth_w900_brochure.pdf

 

 

 

If you want to be baller...

 

 

[Carrotslayer]

So update,

The UPS backup idea didnt work. It was clicking and switching to and from battery in an attempt to provide clean power but this prevented battery from recharging.

[Carrotslayer]

We see some Mini PCs that have chargers for power. I am wondering if I could build a mini pc that would run off a charger? Does it make sense that the same protection that a laptop has to dirty power this method would also have?

[Kisai]

11 hours ago, Carrotslayer said:

We see some Mini PCs that have chargers for power. I am wondering if I could build a mini pc that would run off a charger? Does it make sense that the same protection that a laptop has to dirty power this method would also have?

You would be better off just buying a laptop to be honest. The mini-PC's aren't "being charged", they just have the DC power supply outside, the protection you get from a laptop battery is that it's a laptop and thus the hardware generally runs off the battery 100% of the time there is insufficient power at the DC input. In a desktop with no battery, this doesn't happen.

 

There's two angles here:

1) You can buy standard DC to DC power supplies without needing an inverter.

https://www.powerstream.com/ADC-p006.htm

 

Keep in mind that you MUST take into account the original power brick. If the original brick is 95 watts, then you can replace it with a 240watt model, but not a 45 watt model. Typical car AC outlets are only good to 90 watts and only when the engine is running.

 

Some desktops have these kinds of bricks too, but, then you also have to add the monitor's power on top.

 

Desktops are very likely to be damaged from how much movement a vehicle has, so I'd probably recommend not dealing with a Desktop at all unless your truck already has mounts for one and a monitor/keyboard.

 

2) Get a laptop. You can just plug any laptop brick up to 90 watts into most vehicle inverters, or separate AC inverters. If however if you intend to actually use the laptop while plugged in, the engine may have to be on. 

 

The UPS strategy is kinda a crapshoot since it would only really work if the input power was at least the input power it's rated for eg 5A (600watts) to begin with. So since that doesn't work, let's assume the vehicle's inverter would not support a desktop in the first place requiring more than 300 watts. Remove the inverter from the equation and the power efficiency goes up.

 

 

Between the two, the laptop still works out ahead since the laptop will be charged from normal driving, where the UPS strategy at most would give you 20 minutes and kill the truck and the UPS battery pretty quick. 

[Kisai]

2 minutes ago, Genwyn said:

@Kisai something to note is that most trucks have DC power outputs at 12v 10 amp and 12v 20 amp, outputting 120 or 240 watts

 

DC to DC laptop power bricks are really common at larger truck stops and with a 240 watt outlet there wouldn't be any issue with most laptops, a decently specced gaming laptop would be ideal to run straight from the prefiltered 240w outlets 

That's perfect then, since 240w is pretty much the maximum power brick any laptop will come with.

[Carrotslayer]

So we are going the laptop route but with the powerful device we are looking at i can pretty much guarantee that its brick will exceed 90W. 

@CircleTech @Kisai @genwyn

 

 

[UnwantedLinks]

basically you need a UPS, and a sturdy desk/place to put your pc/laptop

 

or, well thats what my dad told me since he works in the trucking industry too

[trag1c]

On 8/6/2019 at 1:37 PM, BuckGup said:

Couldn't you just idle the truck to keep the alternating going or put a generating on the back if you really need to. Seems like a lot to play games. I'd just get a switch 

I never worked on a semi my self or looked into the tech manuals but even on 1/2 to 5 ton trucks you typically only have an alternator that outputs about 150-250A of current which at 14.4V is only 3600W. Which when you factor in all of the computer modules and other electrical components it doesn't leave much for an 1800W inverter. Especially considering most inverters are more efficient at heating up than changing voltage. You may push your luck for maintaining the batteries.

 

Then you have to factor in that you have to cold start a 10L+ diesel in the morning which is no small feat.  I would guess starters on them beasts are probably drawing around 600-800A. Which the batteries have to sustain for quite some time. So in other words the the batteries have to be in good shape charge wise to actually start the truck.