GeeekPi DC PDU Lite 7-CH 0.5U Rack-Mount Power Distribution Unit for DeskPi Rackmate T1/T0/T2 and 10 Inch Server Cabinet, 7 Outlets, with 3PCS 25cm DC5521 Cables and 3PCS 50cm DC5521 Cables

14 outlets in 7 banks where each bank has a switch, fuse, and indicator light. There are also 2 inputs that are diode isolated. That’s 14 outputs and 2 inputs all using the same plug usually rated at about 5 amps up to 40 volts or so.The user guide is little more than a specifications sheet. It’d be nice if it included a circuit diagram. The PDU is limited in that both the input and output use coaxial plugs. That is one reason for the 8 amp input limit. The isolation diodes on each input may also be a factor in that limit. The 24v maximum is likely needed to avoid harming the indicator lights as they look to be just an LED with a current limiting resistor.Power delivery is the product of voltage and current. The current (amperes, amps) depends upon the size of the conductors. The voltage depends upon the insulation between conductors. The weakest of these sets the capability. The guidelines of 3 amps per channel at up to 24 volts reflect the PDU design requirements. In looking at my collection of external power supplies (walwarts) with these coaxial plugs, I see most are rated at 3 amps or less. The voltage on these things range from 3 volts for the low power things to 20 volts for laptops with 12 volts being most common. That means these power supplies range from about 10 watts to 60 watts nominal average power to 36 watts being most common. My Zimaboard NAS with two old 3.5 drives runs at less than 35 watts. My Raspberry Pi 3 with a 7 inch screen hits 8 watts at idle. My switch runs at 3 watts.The Amazon page is reasonably accurate although there is a voltage drop and the pictures don’t really make the features of the PDU very clear. See the pictures and comments RaceNJason provides in his review: “this is a brilliant idea and could've been sooo much more”. My NAS and services are lower power devices and I am using a 12v 10 A chassis power supply that allows trimming the feed voltage to compensate for the diode drop and some of the line loss. The diodes on each input port provide isolation which could be useful if you want to have a UPS type backup.The switches and indicators are very handy, especially when configuring and testing equipment. The power handling is sufficient for modems, routers, switches, and maybe a 2 drive NAS or home automation server. The fusing is also good to have.

Nice build quality, works as described and the size is on the smaller side of things.

Did not work with Pi 5 devices

I wanted to power 8 Raspberry Pi 5s in my rack. Not just 8 Pi 5s, but with HAILO 8 NPU HATs which means they will lean to the higher side of that limit. This PDU is a nice idea, however, math happens. It only has 6 output channels that handle 3A each total across both ports per channel, not 8 channels, nor 5A per channel. The Pi5 requires a 27W power supply. 8 of those is 216W total when this can only handle 192W MAX (given its max is 24V @ 8A). This does not have enough ports nor the power needed to do what I considered it for. I found a 10-port 300W charging station that fits on a 2U shelf that works perfect for how I need to distribute power in my rackmate rack.

I had a difficult time making a decision on the final rating...let me explain and in so doing will help you understand more than the details being provided by the manufacturer.First this is a brilliant idea and could've been sooo much more. The quality is really nice. The idea of each channel being accessible from both the front and the back is great. You can use this feature just to give your rack a clean look or you can use it to run 2 devices off of each channel (assuming you keep the total current draw under the max rating for each channel and the device total). Each channel comes with it's own switch giving you full control of powering a device regardless if it has it's own power switch (think raspberry pi pre 5). Of course it would've been really nice if some of the power cables also ended in a USB C and USB Mini plug for really easy setup, but you can find that sort of thing if you need it.You can see there are really wide tracks being used on the PCB which should help with low resistance and heat dissipation (if it gets to that). My build includes 2x N305 Mini PCs and 1 router. 1 of the N305s is being connected to a hard drive caddy to manage some 16TB bulk storage drives. You can see on the side of the caddy is a custom power supply that has been internally modded to allow a rear AC power cable (making that plugin you see in the front just a holder that no longer connects to anything - made it convenient and clean looking) and only the 12V rail along with the SATA 12V power connectors remain (oh, and of course a power switch and power light that does go to the front). My N305 mini PCs and router all use 12V brick power supplies. It didn't take long to realize I could just tap into the modded power supply's 12V rail to also power my mini PCs and the router removing the need for 3 brick power supplies and also making it so 1 switch turns them all on.So the build needs a rack and I obviously chose the Rackmate. Little on the pricy side...but, I just wanted to get this finished and done (and looking nice). When I came to the conclusion of distributing my 12V rail from my AC power supply and I saw this...I thought OMG this is perfect. I can just run a nice fat 12V line into this and then plug in my N305s and my router and look...this even comes with individual power switches and protection. I think I was too fast on the "I want this" and "it's perfect for what I want it to do". My N305s have power supplies of 60W each and the router is like 15W. And from being experienced with hardware you want to give yourself a 20% margin on power supply specs. So...60W + 60W + 15W = 135W + 20% = ~169W and then I realized it...this is rated for a maximum of 8A which comes out to 96W@12V total. And each port a max of 5A which comes out to 60W@12V. Yikes...I guess I can get away with running the router but no go on the N305s. And of course if I'm only going to run 1 device off of this there isn't a point to it. But of course there is a point and that has to do with more like SBCs, MCUs and such which in that case it is really good (and something I'm planning to add in the future). So if you like a nice clean setup, it is worth the $60 they are currently asking for it (IF you are using it in the right situation).Now for a big negative that I noticed when I took this apart and something that I believe is VERY important to know, yet I don't see this mentioned anywhere in the details. You can see in one of my pictures that the power input ports both go through a single diode (so the front and rear each have their own). The manufacturer made this decision as a 'safety' feature. I'd assume to make sure custom wired plugs or reverse polarity plugs don't accidently cause a problem. For a lot of PCB engineers this is just common practice...BUT, it has a huge problem. To get voltage to flow through any diode it takes a certain voltage level. And that voltage level is basically subtracted from the other side. In this case there is a 0.5V drop to get through the power diode. So if you plan to run 12V through this, your devices will only get fed 11.5V. Or worse if you put 5V into this, you'll get 4.5V out. Do you know what a raspberry pi does when it drops below 4.6V. Yep, complains and then throttles your CPU.I believe the manufacturer should not have used diodes at all. If you decide to make your own custom wired plug you should know what you are doing. And I'm pretty sure 99.9% of all brick power supplies use normal polarity plugs (if not 100%). They had too many problems with those old reverse polarity plugs that they just stopped making them. Even if you do have one it takes a few minutes to cut the wire, reverse (the reverse) and now it's a normal plug. Leaving those diodes out would provide full voltage to your devices which I think it is what everyone is expecting when they use this.So my dilemma is that I probably cannot use this for what I intended since I would need a 14A rated device rather than a 8A (and even then it would limit me to only those 3 devices) but I can't really doc them on this since when you take a step back it is just DIN plugs. Although a single DIN plug can handle 5A...a single DIN plug (i.e. the power in for this device) is not made to be running some 14A through it. I think this was entirely my fault for not really thinking about this before getting it (hopefully though this review will get you to think about it before you buy it). The quality is nice, the features are nice, the fit is good and only takes up 0.5U (or 1 screw space on the Rackmate). The resettable polyfuses on each channel are good (you can see this in the pics). The diode on the power input is not good...but, now that you know you can either unsolder them and run a (nice thick) wire across the pads or just solder the bridge to both sides of the diode effectively bypassing it. You actually could do this with just one side and then put a sticker on that side showing it is unprotected (but full voltage) where the other will be protected (but causes a 0.5V drop for your devices).For 5 stars this should've been built on a PCB that had a copper layer thick enough to handle (7ch x 6A (5A + 20%)) / 2 = 21A (the divide by 2 is the compromise between cost vs. performance and you are hoping all 7 channels aren't being maxed out simultaneously). I say that because if it shows 1 channel can do 5A before the polyfuse blows it makes you think that all the channels could/should do that (simultaneously). Of course in order to do that you would also need to change the power input to a screw terminal (or other type of higher rated connector). I'd leave the input diode out completely or if absolutely necessary maybe a mechanical switch that can allow for protected/unprotected modes.Anyway my final rating is 4 stars (really 3.5, but I rounded up rather than down in this case because it does have it's use for sure even though it didn't end up working for what I intended it to). This is because I feel like it is being sold in a way that makes you think it covers more scenarios then it really does because of it's total power limitation and the safety power diode. It's hard to ding them on the safety diode...yet, it should be something mentioned in the details then, so someone doesn't plug in a 5V rail and then expect all their Raspberry Pi 4Bs to run without every complaining about low voltage.