The attached image shows measured IV curves for this power supply compared to a 2.0A power supply (Kootek). I generated these with a RPi-based IV curve tracer that I built for solar panels (search for "IV Swinger" on YouTube and/or GitHub if you're interested in knowing more about it). It's not intended for such small voltages, but it worked pretty well.
The IV curves show the current (I) and voltage (V) for different resistances (R). This tells the story about how the supply delivers power for different loads (power = I * V).
You can see that both supplies have an open-circuit voltage of 5.3V. That is the lower rightmost point. R = ∞Ω, I = 0A, P = 0W.
The upper left points of each curve are the closest to R = 0 (short circuit) that we can measure (R = 0.94Ω due to wiring resistance). You can see that the Kootek delivers just about 3A of current and the Canakit delivers about 3.8A. But at this point both are way below 5V (below 3V, in fact.).
An interesting point is where the curves cross their rated current values. The Kootek 2.0A supply crosses 2.0A at about 4.6V (2.0*4.6 = 9.2W). The Canakit 2.5A supply crosses 2.5A at about 4.5V (2.5*4.5 = 11.25W). Both of these are well below 5V. Probably high enough that the RPi won't crash, but cutting it close.
Another interesting point is where the curves cross 5.0V. The Kootek 2.0A supply crosses 5.0V at about 0.8A (0.8*5.0 = 4.0W). The Canakit 2.5A supply crosses 5.0V at about 1.0A (1.0*5.0 = 5.0W).
People who are claiming that this supply doesn't deliver 2.5A are correct - if they are expecting it to deliver 2.5A at 5.0V. But what is important is whether the supply is sufficient for the RPi 3. All I can say for sure is that it does deliver proportionally more power than a 2.0A-rated power supply that has worked fine for me with the Gen 1 RPi B+. For that reason, I'm giving it four stars.
For anyone with specific voltage requirements at the rated (or other) current, you can read the values off the IV curve in my attachment.
This really saved me in the nick-of-time - not all Raspberry Pi boards come with any kind of power supply, so when I realized I had ordered just a Pi without this crucial cable, it was really convenient to find a cheap one boxed up and ready to go. Great product works very much so as expected. I would recommend that if you are purchasing a new raspberry pi as well, that you simply get the CanaKit package that includes the Pi and the power supply and 2 small heat sinks - it will save you some packaging and potentially a couple extra purchases.
There is nothing more irritating then chasing down system hangs or minor peripheral performance issues (wifi, camera) only to find out you have inconsistent power. So I'm very picky about my Raspberry Pi power supplies. When my preferred brand disappeared from Amazon (at least it's current and projected availability) I needed an alternative. After considering a few options, I settled on the CanaKit. I purchased my first of these a couple months ago and have just purchased two more. I find these well built and well performing. I'm interested in seeing how they hold up over time, but have no reason to believe they won't.
I haven’t tried the official Raspberry Pi psu, but of all the ones I have tried (including a 3a charger I bought from WD specifically to run a hard drive and a Pi) this is the only one that has offered clean power with no brown outs and no low voltage notifications.
I was having freezes and crashes before, thought it might be the sd card or pi board itself, but this psu corrected all of that. Running very stable now.
If you’re having similar issues, defibitely give this psu a try.
This review is for the CanaKit 5V 2.5A Raspberry Pi 3 Power Supply / Adapter / Charger (UL Listed)
It works well for my RPI3 (I'm running RetroPie on it). Earlier, I was using a stopgap "phone charger + micro USB cable" solution, but I'd see the rgb color square in one corner of the screen (indicating inadequate power). That problem is now gone.
The plug on this thing fits the micro-USB socket on my RPI3 securely. The power cord could be a bit longer, but I can't justify deducting a star for that. I have not measured its output to verify whether it actually outputs 2.5A (or whether at precisely 5V), but the RPI3 seems to be happy, so I'm happy.
Feature Product
- Tested with all versions of the Raspberry Pi including the Pi 2 and Pi 3
- UL Listed
- 5 Feet cord length
- Micro USB plug
- Output 5V DC 2.5A Regulated Input 100V to 240V AC
Description
2.5A is now a requirement for the Raspberry Pi 3. The CanaKit 2.5A Raspberry Pi power supply / adapter has been specially designed and tested for the new Raspberry Pi 3 and incorporates an inline noise filter for highest stability and reliable operation.
This power supply differs from typical standard 5V USB power supplies in the market in that it can deliver a full 2.5A and still output a voltage well within the USB minimum voltage specifications. Standard 5V USB power supplies in the market have a high voltage drop when the full current is drawn from them which may cause the Raspberry Pi to reboot unexpectedly.
With this power supply, you can power the Raspberry Pi 3 at full load as well as up to 1.2A across the four USB ports. The power supply still has about 0.5A of output power to spare, so even at the maximum current supported by the Raspberry Pi 3, the power supply is not at its absolute maximum.
It is also ideal for use by anyone over-clocking the Raspberry Pi which causes higher power requirements that a lower power adapter may not be able to supply.
What can I say? It does it's job. The micro usb clamps tightly in the raspberry pi 3. The ferrite core was a good idea. It can definitely heat up the SOC and all four usb drives and easily handles extreme overclocking. My LG G4 doesn't get along with it, but my Dell Venue Pro loves it. If you know anything about the Venue line of tablets, you know what I mean. They are very picky about their power sources, and right now it's the only power source it seems to get along with. For some reason the G4 says it's charging and gathering info about the battery, which is something I have never seen, but it just stays at the same percentage no matter how long I leave it plugged in, which isn't long. However as a power source for the Pi 3 it's perfect.
No more little lightning bolt on your screen! This power supply PROPERLY powers the RPi 3 and fits snugly and securely into the micro usb port. I will be buying this supply for all of my Pi projects and I recommend you do the same. DO NOT SKIMP ON THE POWER SUPPLY! For the price, this one is just right.
Get's the gob done. I previoiusly used a 2.1A charger with a plug in usb cable and the voltage drop in the cable was too high causing the low power lightning bolt to appear on the screen. This power supply has no problems and I haven't seen the lightning bolt since installing this one.
I haven't done a complete rundown of these to make certain that they meet their advertised potential. They do work though and work well. I looked around and similar products were twice as expensive. Though they looked to be made of a lot higher quality materials to make up for it.
This isn't the best of the best that can be bought as far as materials go. Though from what I have read some of the choices were better then I can understand. As I am not a professional in any way when it comes to electrical components. It does work though, and I rather have that over fancy looking expensive non-functional any day.
I have a raspberry pi 2b and 3b and the two these adapters I bought are powering them just fine. There have been no issues that are commonly associated with poor power and the Raspberry. Considering that the electrical lines in this house are rather old and not up to snuff that means a lot to me.
Works great. If you are worried about the horrible reviews you read on this product it might be worth noting that even the best computer equipment have their share of factory rejects that somehow made it past the vetting process. This product actually seems to have fewer of them then normal if the reviews are any indication.
I purchased this because I continued to get a low voltage sign in retropie. I am using a Raspberry Pi 3 Model B, not B+. The power supply is great and fixed my issue. Can't recommend enough if you too are getting the low voltage icon and need that extra boost. Also on a side note, I do not have it plugged into the wall. It is plugged into a power strip and still gives me plenty of power to the pi.
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