Completed DIY "laptop" / portable PC (5.4 litres, 17'' screen)

[ruleh]

I just found a big oof with my battery charging.
The boost converter I use does current limiting through a low side sense resistor. However I have all the grounds commoned up, bypassing the sense resistor and defeating the current limiting. This resulted in trying to charge >8 year old empty cells with ~10A and up to 55degC. I didn't notice this before because the half charged battery voltage and internal resistance kept the charge current low enough. Oh well, I guess it's an ultra fast charger for now.

 

[timginter]

PCIe cable should come in a week or two. Tested everything after hole-drilling and started installing software. Trully SFF on the desk

 

[timginter]

Looking at power supplies... I feel I went wrong somewhere. I was looking to power the CPU and charge batteries with 1 PSU, and the GPU with another. @REVOCCASES gave me an idea of using 1, more powerful, power supply for both...

A good, gold-rated, fully modular 550W ATX power supply is around £80, e.g. EVGA SuperNOVA 550 GM 80 Plus. It's smaller (12cm x 10cm x 6cm) and lighter than my current MEAN WELL GST220A24-R7B, and roughly the same price.

I haven't had a PC for a long time, specs say "1 x power 8 pin EPS12V with detachable 4 pin ATX12V section" - do I understand it correctly that I can power my motherboard and GPU from one rail on that PSU? Using 12v input would also open options for modified server PSUs?

I haven't had a PC for a long time, does this even make sense? (HDPLEX requires 16-24V input)

     -- KPPX/KPJX ---------------------- 6pin --- GPU
     |                                   PCIe
     |
ATX --- KPPX/KPJX -- 12-21V ---- UPS --- 6pin --- HDPLEX
PSU                  boost      BOARD    PCIe
                                  |
                                 BMS
                                BOARD
                                  |
                                5S1P
                               BATTERY
                                PACK

GPU will take the most power, so no stepping up/down between it and PSU.
I'll need at least 21V to charge batteries.
HDPLEX will handle any voltage variation from the battery.

Is a 12-21V 200A 200W step-up even sensible with the amount of current?
Can anyone think of problems using ATX PSU externally?
Can anyone think of problems with extending ATX cables - I'm thinking of wiring small cables with, e.g. KPJX to KPPX connectors for easy plug in/out?

 

[ruleh]

Looking at power supplies... I feel I went wrong somewhere. I was looking to power the CPU and charge batteries with 1 PSU, and the GPU with another. @REVOCCASES gave me an idea of using 1, more powerful, power supply for both...

I thought you used different supplies so that they could have different voltages. It also seems a bit more energy efficient but I don't really know.

I haven't had a PC for a long time, specs say "1 x power 8 pin EPS12V with detachable 4 pin ATX12V section" - do I understand it correctly that I can power my motherboard and GPU from one rail on that PSU? Using 12v input would also open options for modified server PSUs?

Apparently all +12V sources are on the same rail, so you should be able to use (almost?) any combination of +12V you want. Though I'm not sure, it's hard to tell without taking the psu apart.

Is a 12-21V 200A step-up even sensible with the amount of current?
Can anyone think of problems using ATX PSU externally?
Can anyone think of problems with extending ATX cables - I'm thinking of wiring small cables with, e.g. KPJX to KPPX connectors for easy plug in/out?

200A might be pushing it a bit.
Most boost converters I saw recently are good for 6-15A but I only looked for adjustable ones with current limiting which shouldn't be needed in this case.
There are still 10-20% losses from converting 12V to 21V and back down to 12V. Depending on the actual power draw, it might not matter.

KPPX connectors should be fine up to 30A for the 4-pin version so it might be possible to connect everything through a single connector (again depending on actual power draw). I don't know if the cables (and contacts) from the supply would handle it though. There might be a decent voltage drop, especially if extended. This should only affect the gpu though. But the psu is modular so it might be possible to connect bigger cables to the supply (without taking it apart).


Would the system boot if a gpu without power is connected to the pcie slot (assuming another gpu is present)?

 

[timginter]

I thought you used different supplies so that they could have different voltages. It also seems a bit more energy efficient but I don't really know.

(...)

Would the system boot if a gpu without power is connected to the pcie slot (assuming another gpu is present)?

I was designing it like a laptop with eGPU, keeping the main weight down and having the dedicated GPU on the desk when extra power is needed, so it would boot with APU's integrated graphics. That's also the reason for 2 power supplies (with a benefit of no boost/buck to charge the battery), but it adds a lot of costs for higher-end GPUs.

To test the setup I looked for the cheapest second-hand CPU the motherboard could support - found a Ryzen 5 3500X. From the benchmarks I actually don't see a big point in upgrading to a Ryzen 5000, unless the difference will be huge or I specifically want an APU (like in the original design). My GPU is around 700 grams (with backplate), so if I don't mind the extra weight I could use one PSU and have the choice of CPUs without integrated graphics.

Modularity and mobility is key here, but I keep forgetting this is no longer a laptop. Even if I bought a 3090 at around 2kg, would I want to use my custom rig without it and plug in the GPU only at my desk, and carry an extra PSU for the full setup? Now I'm more inclined to just have a CPU and GPU with me all the time and use one PSU for both.

200A might be pushing it a bit.
Most boost converters I saw recently are good for 6-15A but I only looked for adjustable ones with current limiting which shouldn't be needed in this case.
There are still 10-20% losses from converting 12V to 21V and back down to 12V. Depending on the actual power draw, it might not matter.

Haha, I meant "200W" I'd need around 160-180W peak for motherboard and CPU. Now I understand the advantage of your diagram with having 12v input straight through to DC-ATX power supply and boost/buck only for the battery - huge advantage.

KPPX connectors should be fine up to 30A for the 4-pin version so it might be possible to connect everything through a single connector (again depending on actual power draw). I don't know if the cables (and contacts) from the supply would handle it though. There might be a decent voltage drop, especially if extended. This should only affect the gpu though. But the psu is modular so it might be possible to connect bigger cables to the supply (without taking it apart).

I'm thinking about 60-90cm from the ATX PSU to HDPLEX, so not a huge extension - just something to have the PSU a bit further away from my lap.


Back to the drawing board Your approach of having 12v straight through is a much better one, I think that leaves me with GxR-ONE DC-ATX PLUGIN 600W PSU from @REVOCCASES and CPU+GPU on one cable - this will really simplify all the cabling.

I'll have to think of a sensible battery solution to keep everything alive at least for a graceful shutdown if not for a sensible amount of work time. Power draw at the plug was ridiculously off, a good "worse-case scenario" - GPU alone displayed 275W under load, but Dell DA-2 is 220W max and my GPU is 175W TDP. Draw at the plug was max 155W when booting, 105W idle, 410W under load.

Thanks for the input everyone, this tinkering project is evolving into something really exciting

 

[timginter]

One day I'll think everything through several times before I start ordering stuff...

Today, though, I think I have the battery sorted. With a 12V input to begin with, the AC-DC and DC-ATX PSUs will not change depending on the battery so I can think them through separately.

Samsung 30Q cells, as before conservative calculations and 90% capacity = 2700mAh. Nominal 3.6V battery = 3.25-4.2V range:

• 4S for 13.09-16.8V range to keep step-down to 12V as small as possible
• recommended discharge: 1C = 2.7A at 2700mAh = 2.7A * 13.09-16.8V = 35.34-45.36W
• maximum discharge: 15A = around 5.5C = 194.37-249.48W
• for 400W peak load:
  • for recommended discharge: 4S10P (or 4S 27000+ mAh pack) - not very practical...
  • for maximum discharge: 4S2P (or 4S 5400+ mAh pack)

I don't expect max load on the battery pack so 4S2P should be enough - just enough juice to unplug and plug in somewhere else, or save gam... work and gracefully shutdown. The problem is stepping it down to 12V at that current.

An alternative could be 7S and something like 800W High Power Step-down Module Constant Voltage/Current to 12V:

• 7S for 22.75-29.4V (the step-down linked above needs input voltage over 20V)
• recommended discharge: 1C = 2.7A at 2700mAh = 2.7A * 22.75-29.4V = 61.42-79.38V
• maximum discharge: 15A = around 5.5C = 337.81-436.59W
• for 400W peak load:
  • for recommended discharge: 7S3P (or 7S 8100+ mAh pack)
  • for maximum discharge: 7S1P (or 7S 2700+ mAh pack)

4S2P is already more cells (and 2x BMS to charge) than 7S1P. Any 1P solution feels neater to not balance each parallel pack separately. 8S1P would also be an option for more reliable high load off of battery.

EDIT:
Looking at any DIY battery packs and balancing, especially with multiple in parallel, I'm tempted more and more to buy a Zippy or Turingy pack, cut it open and rearrange to be flat so it fits in the bottom box - even 7S wouldn't be a problem then

 

[ruleh]

To test the setup I looked for the cheapest second-hand CPU the motherboard could support - found a Ryzen 5 3500X. From the benchmarks I actually don't see a big point in upgrading to a Ryzen 5000, unless the difference will be huge or I specifically want an APU (like in the original design). My GPU is around 700 grams (with backplate), so if I don't mind the extra weight I could use one PSU and have the choice of CPUs without integrated graphics.

An apu is nice to have to do this hybrid gpu thing that some laptops do to save power on idle. Not sure if it's worth giving up a good cpu though.
Also apus seem like the only real way to get a multi gpu setup, given the size and power constraints.

I'm thinking about 60-90cm from the ATX PSU to HDPLEX, so not a huge extension - just something to have the PSU a bit further away from my lap.

With a 6mm2 cable you should get around 0.1V drop and 4W loss at 40A or 0.05V drop and 1W loss at 20A. The hdplex or the boost converter shouldn't care much about the drop. A dc-atx plug shouldn't mind it too much either as long as the psu isn't outputting something very low like 11.5V.
ATX spec for 12V says ±5%, I think. So 11.4V-12.6V? Not sure how things react on either end of this range.

I'll have to think of a sensible battery solution to keep everything alive at least for a graceful shutdown if not for a sensible amount of work time. Power draw at the plug was ridiculously off, a good "worse-case scenario" - GPU alone displayed 275W under load, but Dell DA-2 is 220W max and my GPU is 175W TDP. Draw at the plug was max 155W when booting, 105W idle, 410W under load.

105W at idle seems really wrong. What do you use to measure it?
Maybe it's displaying apparent power and not true power?

Power draw and battery run time for comparison:
Load: 55W -- 40min (stopped load when one cell reached 3.2V)
Idle: 30W -- 100min (system shutdown when bms cut out)
(12W of it is just for the display alone because I don't know how to dim it)
The load was Prime95 running on an a8-9600 APU.
The power draw was measured at the battery using a clamp meter. The battery has old 2200mAh cells in 6S1P configuration.

The gpu (rx480, 150W tdp) draws
110W under load (or 210W, I can't read my handwriting. Either way it seems wrong)
20W idle, output connected
12W idle, output connected, nothing displayed
0-3W idle, output disconnected. [measured with clamp meter only]

I don't expect max load on the battery pack so 4S2P should be enough - just enough juice to unplug and plug in somewhere else, or save gam... work and gracefully shutdown. The problem is stepping it down to 12V at that current.

Something like this claims to support 40A output at 12V.
https://www.ebay.co.uk/itm/DC-DC-Sp...tep-Down-Buck-24V-auf-12V-40A-AH/154279726680
It's hard to tell if it will actually handle it though since none of the components are visible. Though with a 18-35V input range it is not going to work with a 4S setup anyways. It should work for 6S, 7S and 8S.

4S2P is already more cells (and 2x BMS to charge) than 7S1P. Any 1P solution feels neater to not balance each parallel pack separately. 8S1P would also be an option for more reliable high load off of battery.

There is no need for additional balancing in a 2P setup if the cells are wired as series of parallel pairs. Most laptop batteries do it like this.

EDIT:
Looking at any DIY battery packs and balancing, especially with multiple in parallel, I'm tempted more and more to buy a Zippy or Turingy pack, cut it open and rearrange to be flat so it fits in the bottom box - even 7S wouldn't be a problem then

Sounds good. How many cells would fit in total this way? Hopefully the battery pack doesn't have the cells connected with spot welded metal strips.

 

[timginter]

An apu is nice to have to do this hybrid gpu thing that some laptops do to save power on idle. Not sure if it's worth giving up a good cpu though.
Also apus seem like the only real way to get a multi gpu setup, given the size and power constraints.

Zen3 desktop APUs + eGPU should provide really good performance, but if you need mobility + eGPU, a normal laptop would be better. Having a mobile PC workstation will make it bulky by default (I don't mind) - if you're ok with an extra 1kg weight you might as well put the GPU on the rig and use it all the time, ditch the APU for a cheaper/more powerful CPU. Design is flexible, APU+eGPU can be used, but I'm not sure I see the point of an APU any more for this project unless you're going with a mobo larger than ITX. Otherwise everything fits nicely:

Spoiler: hardware layout

With a 6mm2 cable you should get around 0.1V drop and 4W loss at 40A or 0.05V drop and 1W loss at 20A. The hdplex or the boost converter shouldn't care much about the drop. A dc-atx plug shouldn't mind it too much either as long as the psu isn't outputting something very low like 11.5V.
ATX spec for 12V says ±5%, I think. So 11.4V-12.6V? Not sure how things react on either end of this range.

Thanks! You're right, if I decide on extensions I should first check with a wire gauge calculator and then a multimeter before connecting.

105W at idle seems really wrong. What do you use to measure it?

Just a cheap plug power meter - looks like it's totally off, though. Thanks for your numbers - I should probably check with an inline amp meter at the cable, too, if I think I'll be too close to the max.

Something like this claims to support 40A output at 12V.
https://www.ebay.co.uk/itm/DC-DC-Sp...tep-Down-Buck-24V-auf-12V-40A-AH/154279726680
It's hard to tell if it will actually handle it though since none of the components are visible. Though with a 18-35V input range it is not going to work with a 4S setup anyways. It should work for 6S, 7S and 8S.

And thanks again Found a few 50A to match GxR ONE, not sure how reliable those ratings are, though: Szwengao / Daygreen / XWST 12V 50A Step Down DC Converter and Xincol DC 12V 50A converter.
4S sounded simple, but I couldn't find any high current bucks. 7S with a high current buck sounds more and more like a better option.

There is no need for additional balancing in a 2P setup if the cells are wired as series of parallel pairs. Most laptop batteries do it like this.

I'm a lemon I though you'd have to connect each series to a balance board and then connect all balance boards in parallel

Sounds good. How many cells would fit in total this way? Hopefully the battery pack doesn't have the cells connected with spot welded metal strips.

For a 400x260mm board, using battery holder boxes, 18x3 or 4x12 cells (each holder is 76x21mm) if you don't cut the panel to fit the keyboard inside. Quite a lot.
Good point on spot welding - they probably are. Cells seem really good, though - I couldn't find such capacity at a similar price (not including 8000+ mAh from aliexpress). I could always cut a pack and wire the cells up myself.

I contacted Overlander about a custom, flat 7S1P or 7S2P battery, I'll see what they reply.

 

[timginter]

The photo above doesn't have the LCD controller - so close to having a prototype working... When I was screwing the LCD controller in, I damaged an inductor on the board. Didn't notice until I connected everything up and smoke came out from near the screen. One wire on the tape connector literally caught fire At least everything else is still working fine.

Beauty of DIY when you're not careful enough... New controller is due tomorrow, I'll see if just the board is dead or also the screen.

EDIT:
Luckily the screen still works fine. Now just waiting for the new plug-in PSU and prototype's done. Time to get on the battery

 

[timginter]

I tidied up the design and re-did the TinkerCAD drawing.

Mobo + GPU behind the screen made it so top-heavy I'd have to use 7S3P or 7S4P battery to balance it out - not very practical.
For bigger coolers, hardware behind the screen is still an option, with a hinge-stand like Surface Pro have.

With a low profile cooler, hardware in the bottom-box will make it around 5-6cm high, still comfortable when I tested it. I can use the back of the screen to house the batteries

 

[ruleh]

Zen3 desktop APUs + eGPU should provide really good performance, but if you need mobility + eGPU, a normal laptop would be better. Having a mobile PC workstation will make it bulky by default (I don't mind) - if you're ok with an extra 1kg weight you might as well put the GPU on the rig and use it all the time, ditch the APU for a cheaper/more powerful CPU. Design is flexible, APU+eGPU can be used, but I'm not sure I see the point of an APU any more for this project unless you're going with a mobo larger than ITX. Otherwise everything fits nicely:

Yeah it seems like a good cpu + dgpu is the best choice, especially when considering the price and performance difference between a cpu and an apu.
However I need to pass the gpu to a vm and still be able to use the host with 3d acceleration.
Since m.2 gpus aren't really a thing (at least to my knowledge) and sr-iov gpus are insanely expensive, I will have to stick with an apu.
On the bright side I managed to get all the following switchable/hybrid graphics setups working.

And thanks again Found a few 50A to match GxR ONE, not sure how reliable those ratings are, though: Szwengao / Daygreen / XWST 12V 50A Step Down DC Converter and Xincol DC 12V 50A converter.
4S sounded simple, but I couldn't find any high current bucks. 7S with a high current buck sounds more and more like a better option.

Somehow I think the batteries will have more problems with the current than the converters will.
With a 200W load, my battery lasted a full 10 seconds before one of the cells reached 3.1V.

The 180mV ripple on the first converter exceeds 120mV atx spec and the second exceeds max voltage of 12.3V for the GxR-ONE.
Maybe @REVOCCASES knows if it's still ok to use them though.
Ideally the buck output voltage should be less than the ac-dc output voltage but there are load switch modules etc in case it is not. (Maybe a bts5555 would also work here?)
Still, I wonder how much ripple those converters have that don't mention it anywhere.

I'm a lemon I though you'd have to connect each series to a balance board and then connect all balance boards in parallel

That is also an option. I have it kind of like that because the each of the 2 battery holders has an integrated bms. The output is connected to only one of the bms though, so the only benefit it gives is a slightly faster balancing speed. Otherwise it should also increase max charge and discharge current.

For a 400x260mm board, using battery holder boxes, 18x3 or 4x12 cells (each holder is 76x21mm) if you don't cut the panel to fit the keyboard inside. Quite a lot.
Good point on spot welding - they probably are. Cells seem really good, though - I couldn't find such capacity at a similar price (not including 8000+ mAh from aliexpress). I could always cut a pack and wire the cells up myself.

I contacted Overlander about a custom, flat 7S1P or 7S2P battery, I'll see what they reply.

The cells aren't 18650s, are they? The 7S zippy seems to have 21700s or something thereabouts.

The photo above doesn't have the LCD controller - so close to having a prototype working... When I was screwing the LCD controller in, I damaged an inductor on the board. Didn't notice until I connected everything up and smoke came out from near the screen. One wire on the tape connector literally caught fire At least everything else is still working fine.

Beauty of DIY when you're not careful enough... New controller is due tomorrow, I'll see if just the board is dead or also the screen.

EDIT:
Luckily the screen still works fine. Now just waiting for the new plug-in PSU and prototype's done. Time to get on the battery

LCD controllers are cursed. Somehow the lcd controller managed to kill the psu and short out the battery on its hdmi connector.... At least now I know that the bms overcurrent protection works for discharge.

I tidied up the design and re-did the TinkerCAD drawing.

Mobo + GPU behind the screen made it so top-heavy I'd have to use 7S3P or 7S4P battery to balance it out - not very practical.
For bigger coolers, hardware behind the screen is still an option, with a hinge-stand like Surface Pro have.

With a low profile cooler, hardware in the bottom-box will make it around 5-6cm high, still comfortable when I tested it. I can use the back of the screen to house the batteries

Battery with 7S4P would be something like 10h idle runtime or so. I'd do it if I had the space for it (and that many 18650 cells).
Any specific reason why the motherboard is upside down?
Judging by the vent holes, the gpu also seems to be drawing air from the bottom.

 

[timginter]

Since m.2 gpus aren't really a thing (at least to my knowledge) and sr-iov gpus are insanely expensive, I will have to stick with an apu.

Not officially, but you can run a desktop GPU via M.2 with a ADT-Link R43SG or ADT-Link R43SD-WK. I've been running my eGPU build for over 3 years.

On the bright side I managed to get all the following switchable/hybrid graphics setups working.

Nice!

Somehow I think the batteries will have more problems with the current than the converters will.
With a 200W load, my battery lasted a full 10 seconds before one of the cells reached 3.1V.

That must have been funny to watch True, though, 18650 cells would struggle with capacity unless many in parallel. I was aiming to have the battery only as an emergency for graceful shutdown - I'll have to crunch some numbers to check if it even makes sense. Otherwise hybrid sleep is also an option to move from one place/room to another.

The 180mV ripple on the first converter exceeds 120mV atx spec and the second exceeds max voltage of 12.3V for the GxR-ONE.
Maybe @REVOCCASES knows if it's still ok to use them though.
Ideally the buck output voltage should be less than the ac-dc output voltage but there are load switch modules etc in case it is not. (Maybe a bts5555 would also work here?)
Still, I wonder how much ripple those converters have that don't mention it anywhere.

Thanks for spotting that! Second option is also much smaller. I thought GxR ONE takes input up to 12.6V, but @REVOCCASES would be best to clarify.

The cells aren't 18650s, are they? The 7S zippy seems to have 21700s or something thereabouts.

I'm a lemon again... Very true. 18650 may just not have enough capacity for a high-current project like this.
After re-thinking the design, I'm no longer locked to 20mm height for batteries. A proper pack from Turnigy/Zippy should work.

LCD controllers are cursed. Somehow the lcd controller managed to kill the psu and short out the battery on its hdmi connector.... At least now I know that the bms overcurrent protection works for discharge.

Sounds like really bad luck, wonder if the controller was faulty. Probably not the way you wanted to discover overcurrent protection, but glad the pack is OK

Battery with 7S4P would be something like 10h idle runtime or so. I'd do it if I had the space for it (and that many 18650 cells).

Yeah, the battery proves to be a pain - weight+cost vs runtime. If regulating voltage on a high current wasn't such a problem, a 4S3P or 4S4P would have been great.

Any specific reason why the motherboard is upside down?
Judging by the vent holes, the gpu also seems to be drawing air from the bottom.

I'd be paranoid about spilling something if I drilled vent holes on top Felt safer in case of bumps to top or bottom of the rig, too. I haven't tested temperatures at long heavy loads yet, but in case the aluminium panel warms up it shouldn't be a problem on my lap or blanket, etc.
Air circulation should be good so I'm not that bothered by hot air rising.

 

[REVOCCASES]

thought GxR ONE takes input up to 12.6V, but @REVOCCASES would be best to clarify.

My recommendation is to choose an AC-DC PSU with 11.8VDC~12.3VDC output but you can run it safely with 12.6VDC maximum and 11.4VDC minimum.

The AC-DC 12V Power supply used with GxR-ONE should stay within ATX ripple specs.

 

[Choidebu]

Those turnigy/zippy packs are RC/drone grade batteries; they are built to do high current (high Cs). They are LiPo cells; safety (and density to some extent) are tradeoff to higher specific energy.

In RC usage, you'd have your pack and some more backups charged up by a balance charger. You can parallel or series them in use as long as you keep an eye on their respective voltages; but nobody charge them in series, afaik.

For your use case I'd definitely go for lipo packs. Pouch cells just lend itself better in thin but wide form factor like laptops. There's all kinds of voltages and capacities our there, with C number from 24, 40 all the way to 60C (beware of C rating beyond this).

 

[timginter]

Those turnigy/zippy packs are RC/drone grade batteries; they are built to do high current (high Cs). They are LiPo cells; safety (and density to some extent) are tradeoff to higher specific energy.

In RC usage, you'd have your pack and some more backups charged up by a balance charger. You can parallel or series them in use as long as you keep an eye on their respective voltages; but nobody charge them in series, afaik.

For your use case I'd definitely go for lipo packs. Pouch cells just lend itself better in thin but wide form factor like laptops. There's all kinds of voltages and capacities our there, with C number from 24, 40 all the way to 60C (beware of C rating beyond this).

Yeah, I came to the same conclusion... after all the reading, figuring out, number-crunching and finding ridiculous converters I updated the parts list 4 hours before your post, actually.

I'm waiting for the ZIPPY Compact 8000mAh 3S1P 30C Lipo Pack and the plug-in PSU to come. 3S packs are much cheaper and the voltage range is pretty much spot-on for GxR-ONE with a Schottky diode keeping max battery voltage below its max 12.6V. Staying below 9000mAh (below 100Wh at 11.1V) for airport regulation will mean around 12 minutes at 500W - not exactly AAA gaming on battery That's not what it's there for, though - will leave plenty of time to save work, shut down or plug in somewhere else.

If I didn't want to stay within airport regs, there are also 20000mAh packs. Or a few in parallel.

 

[ruleh]

Not officially, but you can run a desktop GPU via M.2 with a ADT-Link R43SG or ADT-Link R43SD-WK. I've been running my eGPU build for over 3 years.

That's a nice egpu build.
Running a gpu over m.2 + a decent cpu does seem to be the the better option compared to an apu.
I think running a rx480 on the pcie slot and something low power like an r7 240 on m.2 would be good enough.
That is if I can make it all fit inside the case.

That must have been funny to watch True, though, 18650 cells would struggle with capacity unless many in parallel. I was aiming to have the battery only as an emergency for graceful shutdown - I'll have to crunch some numbers to check if it even makes sense. Otherwise hybrid sleep is also an option to move from one place/room to another.

Turns out those cells are only rated for 5A and I was pulling up to 10A.
I wanted to test a 6S2P config but one of the cells doesn't want to take a charge above 3.8V and instead just gets really hot.

Sounds like really bad luck, wonder if the controller was faulty. Probably not the way you wanted to discover overcurrent protection, but glad the pack is OK

The controller seems ok. At least I hope it is. It is still in use after all.

Yeah, the battery proves to be a pain - weight+cost vs runtime. If regulating voltage on a high current wasn't such a problem, a 4S3P or 4S4P would have been great.

If high current stuff was easier, a 1S12P configuration would seem like an interesting idea. No need for balancing but >100A current

I'd be paranoid about spilling something if I drilled vent holes on top Felt safer in case of bumps to top or bottom of the rig, too. I haven't tested temperatures at long heavy loads yet, but in case the aluminium panel warms up it shouldn't be a problem on my lap or blanket, etc.
Air circulation should be good so I'm not that bothered by hot air rising.

Yeah, as long as the sides stay open, heat shouldn't be too much of a problem. I didn't think too much about it and now I have 60˚C hot air trapped inside the case.

Yeah, I came to the same conclusion... after all the reading, figuring out, number-crunching and finding ridiculous converters I updated the parts list 4 hours before your post, actually.

I'm waiting for the ZIPPY Compact 8000mAh 3S1P 30C Lipo Pack and the plug-in PSU to come. 3S packs are much cheaper and the voltage range is pretty much spot-on for GxR-ONE with a Schottky diode keeping max battery voltage below its max 12.6V. Staying below 9000mAh (below 100Wh at 11.1V) for airport regulation will mean around 12 minutes at 500W - not exactly AAA gaming on battery That's not what it's there for, though - will leave plenty of time to save work, shut down or plug in somewhere else.

If I didn't want to stay within airport regs, there are also 20000mAh packs. Or a few in parallel.

The voltage range of 9.6V-12.6V for the pack is wider than the 11.4V-12.6V range for the GxR-ONE. Or am I missing something?

 

[timginter]

That's a nice egpu build.
Running a gpu over m.2 + a decent cpu does seem to be the the better option compared to an apu.
I think running a rx480 on the pcie slot and something low power like an r7 240 on m.2 would be good enough.
That is if I can make it all fit inside the case.

Thanks, hope it helps. M.2 worked great for me, as long as the M.2 port has 4 direct lanes, max performance loss will be 5% (compared to much more and more expensive on Thunderbolt)
The only "problem" was using the eGPU on laptop's screen - nVidia uses compression with Optane drivers so bandwidth wasn't an issue, but AMD didn't works as well. No issues with either when connecting a monitor directly to the graphics card, though.

If high current stuff was easier, a 1S12P configuration would seem like an interesting idea. No need for balancing but >100A current

That just sounds scary

Yeah, as long as the sides stay open, heat shouldn't be too much of a problem. I didn't think too much about it and now I have 60˚C hot air trapped inside the case.

Yeah, I was quite surprised after seeing how much cooler my eGPU runs just sitting on the desk

The voltage range of 9.6V-12.6V for the pack is wider than the 11.4V-12.6V range for the GxR-ONE. Or am I missing something?

Officially, yes and I don't advise going outside of this range.

From what I've read, higher voltage may damage. Lower voltage will cause more current draw to compensate, but as long as within spec the device should be ok. Too low voltage and a device should just turn off and not work.

For 3S 11.1V LiPo, it's advised to stop discharge at 10.5V. I've spoken to someone with more electrical knowledge than mine (not a tall order there ) and some 12V appliances should be ok with 10V. Another, also experienced person, said they should be ok with as low as 9.5V. No names because I do not advise using an appliance outside of its official spec and I don't want anyone blaming someone else if things go wrong.
It's something I still have to test and I will be praying hard that I don't fry anything, but as before - I'm doing it at my own risk.

If everything is ok, though, it will give me a neat and cheap battery power using an official RC power pack and with no high-current conversion. There will be a BMS between the battery and the ATX-PSU so I'll check if there's a voltage drop from the BMS - if not, I'll add a MOSFET or a Schottky diode between BMS and ATX-PSU to lower the battery's maximum 12.6V a bit, just in case

 

[Nichronos]

Hello, this project has a great idea but has no future.
Everyone can just use an Skyreach S4 Mini, CustomMod SLM1 or inexpensive K39 case with the Nexdock screen/keyboard combo in portable and compact 13 inch DSLR or laptop bag (depending on the chassis of choice). I carry the same thing 24/7 every single day for over 2 years now and its still the only variable solution up to date...

 

[timginter]

Hello, this project has a great idea but has no future.

Hi and thanks. Commercial future - probably not (unless heavily refined), but it's not intended to be produced and sold. Not entirely sure what future you mean, though - it's a DIY hobby project, I wrote the reasons for it and my goals in the first post.

Everyone can just use an Skyreach S4 Mini, CustomMod SLM1 or inexpensive K39 case with the Nexdock screen/keyboard combo in portable and compact 13 inch DSLR or laptop bag (depending on the chassis of choice). I carry the same thing 24/7 every single day for over 2 years now and its still the only variable solution up to date...

Definitely - if compact, max 213mm GPU and 13'' is what someone wants that sounds like a better route.

My goal was not a 13'' half-ready solution, though. I also have a 14'' laptop for carrying around and work on.

I've had some great discussions about hardware and electrics/electronics thanks to this thread. For me, the "future" of this project already surpassed my expectations - I've read and learned much more than I expected, had a creative hands-on hobby for COVID lockdown and electrocuted myself only once

 

[CC Ricers]

Following this closely because it meets some of the same goals I'm looking to do in terms of portability and power management. Mine is going somewhat smaller, though- like a 7 to 8 inch netbook size I'd like to see how your power solution ends up working, esp. since it will consume far more power than my project and there are S4 Mini builds that also used a battery pack.