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KwH Energy Monitor Save Energy

by Hugo Brennenstuhl
3.7 out of 5 stars  See all reviews (12 customer reviews)

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  • KwH power monitor
  • Batery backup - so settings not lost when taken from power outlet
  • Energy consumption in Watts, Amps and cos phi.
  • Total energy consumption during measuring time
  • Includes batteries
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Product details

  • Boxed-product Weight: 200 g
  • Delivery Destinations: Visit the Delivery Destinations Help page to see where this item can be delivered.
    Find out more about our Delivery Rates and Returns Policy
  • ASIN: B000XSX1PA
  • Date first available at Amazon.co.uk: 25 Oct 2007
  • Average Customer Review: 3.7 out of 5 stars  See all reviews (12 customer reviews)

Product Description

An energy monitoring plug which enables readout of electricity consumption and running costs of connected appliances. You can calculate the cost of running appliances over a period and obtain the cumulative cost.

Customer Questions & Answers

Customer Reviews

Most Helpful Customer Reviews
59 of 60 people found the following review helpful
2.0 out of 5 stars Positives: battery, negatives: everything else! 20 Sep 2008
Verified Purchase
Having batteries to store the measurements is a good idea, making them readable after you've unplugged the meter and appliance (no problems if the plug socket is awkward to get to). Unfortunately, this useful feature doesn't compensate for the other weak points of this power meter.

The Brennenstuhl meter isn't well suited to measuring power consumption accurately for household appliances, for various reasons. It has a low current threshold, so doesn't give any readings for appliances that draw a low current. This can be a problem not only for measuring standby power usage, but also for measuring some low-consumption appliances when they're switched on (e.g. portable radio). When the current is above the threshold, the power measurements aren't always accurate. I've compared the Brennenstuhl against another meter (Plug-In Power and Energy Monitor Meter), and the Brennenstuhl usually overestimates the power (it's readings look more like "apparent power" than "actual power"). For example on a low-energy light bulb, rated at 11W, the Brennenstuhl measured the power at 15W; the other meter measured correctly at 11W.

(Measuring actual power for AC devices is not straight forward: the shape of the AC current and the phase difference between voltage and current need to be measured. The apparent power is easier to calculate as it makes simplifying assumptions about the current signal and phase, but isn't a useful figure: power companies don't charge you for "apparent" consumption! The power factor is the ratio of apparent and actual power. Not all power meters can measure the power factor and actual power consumed by a device).
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7 of 7 people found the following review helpful
+ Measure power drawn during normal usage
+ Batteries to store readings so that you can plug out from mains before taking readings
+ Show voltage, current, watt, duration, KWh, cost based on KWh and clock

- Inaccurate, seems to give larger values than actual power drawn. Give 17W reading for a 13W lamp
- Doesn't show low values. For some devices, e.g. clock, it gives a reading of 0W. The lowest reading that I have is 7W, hence it doesn't show anything between 0-7W and is not suitable to measure low standby power drawn accurately.
- Too wide to insert into some power extension plugs, will eat into space for next plug

If I have read "Howard Wright" review first, I would have buy the other meter instead of this. Although the other meter does not have batteries, you can work around it by using extension cable/plug. However you can't work around the inaccuracy of this meter.
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8 of 9 people found the following review helpful
3.0 out of 5 stars It has one good point - it has a battery! 14 Aug 2008
The Brennenstuhl meter is ugly as sin, a hideous lump of grey plastic with an undersized lcd screen that looks like a soviet era leftover. But you're not buying it to put on the mantlepiece, so the question is how does it perform?

There are plenty of sleeker products that do the same job, but the Brennenstuhl has one virtue to commend it, and it is an important virtue - it has a battery!! This means - as the first reviewer has said - that it can be unplugged from the appliance to read the recorded data in comfort. Much better than having to ram your head into the space between the sink and the washing machine to read it in situ!

Performance-wise it does what it claims. There is one, really irritating shortcoming - the timer stops working if the appliance being monitored "uses too little current". How stupid is that? It means that if you monitor the fridge or something that cuts in and out on a thermostat the timer doesn't record the monitoring period correctly - you have to make a note of the time it started and ended.

This product fulfills a need but IMO looks outdated and but for the battery it wouldn't get a look in!
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13 of 15 people found the following review helpful
4.0 out of 5 stars Bulky 8 July 2008
Verified Purchase
There are plenty of different ways to display power consumption and the unit appears to provide relatively accurate readings. The truth is it doesn't have to be *that* accurate anyway because the odd watt here or there isn't important.

The instruction leaflet is small but explains what the various switchable modes do. It doesn't say if there are some sorts of load that can't be measured properly, though it does give figures for overall accuracy.

From a practical perspective the case is relatively bulky and will extend about 5cm below any socket you plug it in to. If you've got one of those plugin timer units, then this is much the same size. It's width may mean it won't fit next to some plugs in one of those multi-way socket blocks. The lead from whatever you've plugged in will drop over the screen making it harder to read. The screen isn't back lit. Finally, the battery compartment lid is a *very* tight fit and will have to be prised off with a screwdriver.

It's good enough for you to be able to work out what really needs to be switched of and what doesn't. You my be surprised to find out just how much your phone charger really uses on standby...
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2 of 2 people found the following review helpful
3.0 out of 5 stars Confusing to use 19 Nov 2009
By Bluebell TOP 100 REVIEWER
I bought this because I thought that having a battery back-up for the readings would be an advantage. However, I find the device very fiddly to use having to press a small button up to 9 times to get the various readings and then the units for each reading as so small I can't easily see them. I'm not convinced that the device it accurate for monitoring devices that have a low energy usage and so I'm going to buy another, simpler device to replace it.
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Most Recent Customer Reviews
3.0 out of 5 stars OK, but hard to read
This does what it says on the tin but, unfortunately, the readings reset when you unplug it. Some of our plugs for appliances are tucked away in cupboards (especially washing... Read more
Published on 27 Mar 2012 by Mr. R. Davis
4.0 out of 5 stars OK
A good product - does what it says on the tin. Display a bit small and obscured by the lead of the appliance that's plugged in to it. Read more
Published on 4 April 2010 by Mr. D. I. Richardson
5.0 out of 5 stars Excellent for calculating a bill
This device can record total KWh units used over a long period, e.g. a month and was the only one I found that could do this. Read more
Published on 9 April 2009 by plexos
5.0 out of 5 stars fascinating!
Thanks to the purchase of this little gadget we are a bit more frugal with boiling the kettle - never knew how much it was costing! Read more
Published on 6 Nov 2008 by L. Summerscales
3.0 out of 5 stars Out of three they all give slightly different readings
I bought three of these and they each give slightly different readings (this includes simple readings such as current and voltage). Read more
Published on 7 Oct 2008 by Sirius76
5.0 out of 5 stars Hooray for batteries
It's only when you've used one of the other devices that you realise what's wrong with them and what's right with this one: it uses batteries. Read more
Published on 13 Jun 2008 by R. Simons
4.0 out of 5 stars Very good, but some things aren't so simple
Does what it says on the tin,
however, it is for measuring sinusoidal loads - which doesn't include things like computers and laptops - these will give an inaccurate reading.
Published on 27 May 2008 by Steven Aitken
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