P3 International P4456 Kill A Watt Flex Electricity Usage Monitor – Advanced Power Meter with Data Memory, CO₂ Tracking & Cost Calculator – Upgrade from P4400 Watt Meter

Tried to see what exactly made my electricity bill go up, and this was the product for it! Plugged it in, and almost instantly got results. After realizing it was a space heater, the product paid for itself when I decided to unplug it and save money on my bill. Great product, excellent accuracy, and great price!

It took google and chat gpt to figure out how to input cost rates, but after that, really good. They need to improve the manual or make videos. This has been pointed out by many, and I concur, its bad. I really wanted to see how efficient an electric 1500 watt portable oil heater was, and after running it for a few days, at a 73 degree setting in a 10x10 office in November in CT, about 35 degrees outside, its about 21 bucks a month, much better i assume than my electric baseboard. The heater is on medium setting (750 watt?) with the dial about 1/3 open. I need my office warm, (or hot if you ask my wife), so the device works for me. This is not a review on my heater, but confirmation on its efficiency thanks to this device. If you wonder how much devices cost, this will help. Oil heat taks time to heat up, so I leave it on, so I guess I would need to factor in baseboard, on and off, but not sure. I give it five stars, as they can easily improve the manual, but it does what I wanted. I wish I could check my baseboard heater, but I cant. At least I can see what I'm using, could be a ballpark, but better than guessing.

This is a great product at a great price! The P3 Kill A Watt makes it easy to track how much power each device uses, showing daily, weekly, and monthly costs. It’s been really helpful in figuring out which appliances are driving up my electric bill. The only downside is that it takes up the whole outlet when plugged in, but honestly, it’s worth it if you’re serious about cutting down your energy use and saving money. Highly recommend for anyone trying to get control of their electricity costs!

Do not buy this model, the EZ model is superior and $20 cheaper. Before purchasing, I couldn't find any information online about the differences between this "Flex P4456" model and the "EZ P4460" one, but I went with this one because the reviews made it sound like it has the same features as the P4460 but with CO2 calculation and improved internal electronics. I could not find the manual until after receiving this product, it only comes with 2 pages of it (tucked between cardboard, almost accidentally threw it out) and a link to get the full manual on their website p3.club/p4466). The box itself even lies, it says "Displays these 8 units of measure:", and lists "Frequency (Hz)" and "Power Factor (PF)". There is actually no frequency measurement, you can see there isn't even "Hz" in the LCD when it first powers on, there is no combination of button presses that displays any number close to 60, meaning it would be impossible for it to display frequency with units, and the online manual itself has no mention of "Frequency", and Power Factor (PF) has to be calculated yourself by dividing the real power reading in Watts by the apparent power reading in Volt-Amps. So much for "Specifications may change without notice". I am at least grateful power factor can be calculated with this instrument (it is better to display Volt-Amps and let the user calculate it themselves than straight-up removing the feature, like they did frequency measurement), be weary Residential users are only billed for real power and apparent power is the "load" it puts on the grid with reactive power. It is fun to use this to measure power factor of various appliances around the house, won't believe how bad of a power factor some of your devices have! Anyways, I was recommended this brand when looking for a household power meter. Indeed, it seems these guys have been around for a while, however I am a bit disappointed by their lack of documentation (as mentioned). First of all, I had no idea what specific features this "Flex" model has that the P4460 "EZ" doesn't, by comparing the descriptions and reviews it seems like the only difference is the CO2 calculation and improved internal, but the CO2 and Energy Price calculation are made pointless by utility Time of Use (ToU) rates, and you will need to look up your utility and how much you pay per kWh and approximate CO2 per kWh, both of which can thankfully be configured (unlike what other reviews claim, however the manual doesn't specify what the units are in, only says "rate"). The default of $0.25/kWh was a little over 200% what my utility charges for my plan, so don't trust the default to be accurate. As stated, this product lacks the promised frequency meausrement, however it can display RMS Voltage. I'm not sure of the accuracy, and the min/max voltage are also kinda silly because there are no details about the time period the device measures over, and the operation voltage is described as 115–125 V, so it may not measure large drops for long. At least it is good this model features saving measurements when unplugged (be sure to reset them when measuring kWh for another device), and will account for the time a device is not powered (ideal for something like lights on a timer or fridges which are variable loads). There is no details about how big of a drop in power is considered "powered off". At the end of the day, this does fulfill its most basic purpose to measure the real and apparent power devices consume. It is up to you to change your behavior to reduce power usage and achieve the claim on the box "Empowers you to save $100s", which wasn't really my goal (I was just curious how much power different devices draw), but I did find about 50 W (100 VA) of surprisingly power-hungry devices in standby in less than an hour (though be aware devices often change load after they are first unplugged and then plugged back in, and may intermittently draw larger loads when idle). The device does seem to be build pretty well, though I'm not sure how long until the plugs become loose from unplugging and plugging devices into it. Just be gentle, don't purposely try to wiggle stuff while plugged. Pleased with the essential functionality, but disappointed by the advertising.

It works well and easy to use capturing peak power.

Have owned other P3 devices in the past. This one looks fine at first start, but it only comes with a quickstart guide which is next to useless. There is no manual online for the P4456, only the 12 year old P4460. When you call the phone number listed on the quick start guide dated 2023 it says the number is not in service. As another reviewer said does not measure\show HZ. Just get the P4460. It does everything this one does and contains a manual to explain how to enter\toggle the features.

I had two purposes for this device. The first was to see how much power it took to keep my portable refrigerator at temperature, so I would know what capacity solar power station it would take to keep it cold. The second was to refute the claim of my ISP that the reason for intermittent dips in bandwidth must be that my modem was rebooting due to voltage drops. It turns out the 4456 will do both. The difference between the 4456 and the 4460 is not easy to discern, but as the web site says, the 4456 has a battery and will hold data when it is unplugged. The web site also vaguely refers to voltage drops, and I can confirm that the 4456 will give you maximum and minimum voltage over a period of time in "Pro" mode. To do all this you have to decipher the "manual," an interesting document with the pages numbered right to left. Mine has English captions so I was able to do it, but it made my brain hurt. I am just starting to use it so I will report back if I Iearn anything new.

It delivered fast and works like a charm. I never knew how much money I was wasting in my home. Drastic changes are coming. Watch out kids!