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Dec 24, 2004, 03:10 PM
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kevin's Avatar

"Watts Up" meter - tested

Keith from RC Electronics, Inc. posted a message about their new “Watt’s Up” watt meter and power analyzer in one of the Ezone forums. He introduced his new product to the forum and later in his post asked for potential testers. I responded that I would be interested in comparing his new meter to my trusty AstoFlight Whattmeter. I have been using a Wattmeter since I first began my electric RC fascination in early 1999. The Whattmeter has been an invaluable source of information on my power systems. Now there are many other meters on the market, this test compares one of the other options.

I must state that I am also an Ezone author. This product test in an informal evaluation of the “Watt's Up” meter. There is a formal review of the “Watt’s Up” posted on the front page of Ezone. If you are looking for the full specifics of the meter please check there or on RC Electronics, Inc. website. Some quick specs include: Measures energy (Wh), charge (Ah), power(w), current (a) and voltage (v) - also measures current peak and voltage drop. It can also measure down to 0 volts with the use of an optional external battery.

The first thing that caught my eyes when I opened the box, besides the blue color, was the small size of the meter. The meter comes without connectors, so I attached a set of Deans ultra connectors. Inside the box with the manual was a small instruction sheet outlining the key features of the meter.

In the past I have noticed that many of my RC specific equipment (chargers, meters) didn’t match my digital volt meter exactly. I was very curious to see how close the Watt’s up meter was. (I have a dvm that was measured against two fluke dvm’s that are used at the TV/Radio stations where I work. They have their meters calibrated and my dvm matched exactly, so I am pretty sure of the voltage measurement that I took comparing my two meters to the actual battery voltage.

First measurement compared voltage of the two meters with a 3s lithium battery pack. The actual pack voltage measured 12.29 volts. The Whattmeter read 12.1 volts and the Watt’s Up meter read 12.23 volts (The Watt's up meter measures voltage to one extra digit. Note. My Whattmeter is 5 years old, newer versions have different specifications.Also notice that the Watt's Up meters load and source are on opposite sides when compared to the Whattmeter. )
I then ran the meters in series to take voltage readings at the same time. In the last picture, the Whattmeter is hooked on the Watts up meter for the reading. Note the current draw and slight votage drop the Watt's up meter reads. (note. The Watts Up meter captures peak current and voltage minimum on a seperate screen that switches from the main screen every three seconds.This is a very handy feature !!)

more to come.
Last edited by kevin; Dec 24, 2004 at 04:32 PM.
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Dec 24, 2004, 03:51 PM
Registered User
kevin's Avatar

more testing

My next test was to run the meter in a power system. In the pictures, the meter is being used with a Himaxx 2015-5400motor in a C drive gearbox, 8x6 prop, and a 3s 1570 lithium battery pack. I also ran the Whattmeter to compare the two. The tests were run by swapping which meter went first in alternating tests. The Watts up meter was always higher in voltage and current(the Watt's up meter reads an extra digit.). (closer to actual in voltage). At this point I have no way of having an actual watt or current measurement, so I cannot say with any certainty that any one of those readings is closer to actual for either meter.)

The first picture shows a size comparison between the two meters. The second and third pictures show the meters being run at about 2.5 amps,and 5 amps. The last picture shows the peak current and minimum volt screen captured well after a test run at 14.9 amps (140 watts / not read in the peak capture screen. (I wish it was). Although I did alternate which meter was upstream in series, my pictures show the Whattmeter down stream. Note. even with the Whattmeter hooked to the Watt's Up meter, The Watt's up meter reads a higher voltage.
Last edited by kevin; Dec 24, 2004 at 04:36 PM.
Dec 24, 2004, 04:25 PM
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kevin's Avatar

additional info

I am still working on other tests to compare the two meters at higher power levels (my highest as of this writing is 540 watts) So far, The Watt's up meter always reads the current and voltage higher than the Whattmeter, although they go back and forth on the watt reading. The readings as you would imagine, are always very similar. I consider the voltage reading (based on the dvm comparison)on the Watt's up meter to be more acurate which is a big benefit when dealing with potentially dangerous lithium batteris. Another big benefit is the ability to look at the peak current and voltage drop readings.

So to sum it up for now. (again-My Whattmeter is 5 years old, there are new Whattmeters on the market with more features. Also the Medusa products as well as others.)

Pros for the Watt's up meter.
Small size, light weight, reading resolution to .00, clear easy to read display, Rugged (yes, I already dropped it), Peak and minimum readings on the alternate screen.

Cons. Well, they are not really cons but I would like to be able to capture peak watt levels. Also, at certain times it would be nice to be able to stop the screen from switching in the middle of a reading. A small switch or button that would allow you to switch to the peak screen after a test would be nice.

Overall I am very impressed with the new meter. It has replace my Whattmeter in my travel case, and elsewhere, because of its improved features and small size.

If anyone would like to see some form of additional test as well, respond to this thread and I will see what I can do.
Last edited by kevin; Dec 24, 2004 at 04:38 PM.
Dec 24, 2004, 09:07 PM
Southern Pride
everydayflyer's Avatar
I love the name . Back in the early 90s' I wrote a electric column for one of our local club Newsletters.Guess what the column was called.

Feb 13, 2005, 06:14 PM
Registered User
kevin's Avatar

quick update

just a quick update on the watts up. After using it for some time now, i like it more than ever. The are a couple of small things i wanted to mention as an ongoing tester. i am amazed at the crispness of the display, much better than even my rather expensive charger's display. the peak amp capture function has been great,now i just run my motors full bore and shut them down right away. this lets me know if i am within my esc and motor rating without running my power system for any extended periods of time. one more thing, the see through case is a hit with everyone (including me) that i have lent it to. it is interesting to be able to look inside at the "guts". more later.
Feb 13, 2005, 08:12 PM
one game away...
PerfectStranger's Avatar
agreed. fine piece of equipment.

Dec 20, 2009, 04:35 AM
Registered User

3 wire hookup

Hello everyone , I too am very happy with the watts up meter and have used it a lot on the model planes I have .

I have found another use for it . The electric bike that I'm fooling around with ..

The Question is .. Watts Up shows a 3 wire hookup where you only use the in and out ground and a small size "In" for the positive .. So.......

Why would you ever hook it up the other way if you do't need to???? This
is a lot easier to do than the 4 wire .. Is there some advantage to the 4 wire hookup ???

Thanks Again for all the help , Don J.
Dec 20, 2009, 10:12 AM
jackerbes's Avatar
I looked at the choices when I got mine and considered it easier and preferable for me to simply put male and female Dean's Ultra connectors on the ends of the existing wires.

To use the three wire method would have had a "extra" external run of wire (of the same guage as the negative leads) crossing over behind the case or something like that. Then a tap would be needed to be put on that wire with the smaller gauge wire, and the smaller gauge wire was going to have to be spliced the larger gauge wire outside the case.

All of that was going to be unsightly and even somewhat entangling in comparison to just adding connectors for the four wire hookup.

When I store mine I plug the source and load leads together and it makes a small, compact unit that fits nicely into my TX case.

I've used mine at up to 65A or so and for extended periods of time (one or two minutes at full load, up to five or six minutes for loads of 5 to 20 Amps) and never even noticed it get warm to the touch.

The manual described the three wire hookup as being the "highest performance" but I don't understand how or where that performance is seen or measured. I've quoted that section of the user's manual below

----quoted from manual----
7.5 Connection Diagrams

<snip portion about four-wire connection>

A "three-wire" connection only connects the meter's red (plus) lead at the LOAD or the
SOURCE, but not both. A separate wire must be present to make the SOURCE to LOAD
(e.g. battery to speed control) connection "around" the meter. The advantage of the threewire connection is that only the meter's black wires must carry current and therefore be heavy and that the heat generated in the meter is reduced since there is only low current in the red voltage sense wire to the meter.

An example three-wire hookup is shown in the diagram for reset and transient
voltage protection further on in this document. Generally, the three-wire connection is the highest performance and is recommended.

The four-wire "jumper cable" approach can be easier to understand and may simplify connector usage.
---end of quote from manual---

Dec 21, 2009, 03:15 AM
Registered User
GryphonRCU's Avatar
I damaged (2) of these in a row.

After the first time, they were nice enough to give me another one by contacting my local hobby store where I had bought it.

After the 2nd time, and a few phone calls: I insisted to have their tech talk to Castle Creations tech.

Bottom line: They told me there is incompatibility with wattsupmeter and Castle Creations Phoenix 80A ESC due to its large capacitors.
Big spark on initial connection.....bigger spark on 4S and my 5S connection is probably what killed the meter.
It started showing 11.6V for 3S pack fresh from charger instead of 12.6V.
I was told to rig some kind of harness on next meter and use a switch inline and not use one of the main wires coming out of meter etc....(I don't remember the details much).
I said no thanks, I got my money back.

Since I needed a tach anyway, and that would be extra ($20-$30), I bought a Hyperion e-meter for $90 (now sold out and they are up to V2 for more money than I can afford).

The E-meter cannot be damaged from that initial spark of ESC since it has on/off switch and also for the fact that the shunt can be disconnected from main body as it gets connected to battery and ESC.
Had a ton more features too…make that 2 tons more features.

I did like the features of my wattsupmeter, but 2 of them were damaged too easily by my ESC's initial connection to 5S battery pack. I never drew more than low 70A for short duration.

That was 2 plus years ago and I hope they have fixed the issue...Their tech stating incompatibility with Phoenix 80A ESC didn't leave me much choice.

I wish all of you the best with this meter and I do wish the best for the company.....excellent customer service.

Dec 21, 2009, 03:19 PM
jackerbes's Avatar
The issue must be the inrush of current as the capacitors in the ESC are charged.

I have a Phoenix 80 and have used it with my Watt's Up meter many times without any problems. Was the only issue that you had? That 12.6V was displayed as 11.6V?

Dec 21, 2009, 06:26 PM
Registered User
GryphonRCU's Avatar

My issue was that the meter took some damage and was giving me inaccurate info.

I still do recommend this meter to people with other ESCs. I never stopped recommending this meter.

I do like this meter and I do like the company...very much so.

I believe my 5S pack connections (biggest spark) to my CC80A is the reason for damage to meter.


I am aware that there are also ways to ensure there is absolutely no spark during a pack connection. It can be done through using a resistor etc...(resistor does not stay inline after the first second).

***Wrong size resistor can confuse the Auto Lipoly cell count feature of Castle ESC.

If interested I will place a link or some article that I downloaded.

Castle techs can tell you the size of resistor needed given various voltages for their various ESC's. I have not implemented it myself but my internet buddy did it after I mentioned it. This practice is common for many. Maybe my friend would be willing to show some of his pics on CC125A and CC180A. The size of resistor used was recommended to him by Castle techs. He uses Eagle tree data logger 150A do I.

Let me know if you like to see how a “no spark” connection can be done. PM or post.

Have fun,

Dec 29, 2009, 03:57 AM
You down with EPP?
johnnyrocco123's Avatar
Do you know anything about the Turnigy watt meter?

I fried my "watts up" and was looking at the turnigy at half the price.
Dec 29, 2009, 07:46 AM
Registered Drug Free
LunaRendezvous's Avatar
it's 37% cheaper not 50%
go on buy it I dare you.
Dec 29, 2009, 12:29 PM
You down with EPP?
johnnyrocco123's Avatar
[QUOTE=LunaRendezvous;13927117]it's 37% cheaper not 50%
go on buy it I dare you.[/QUO

Is the sarcasm from experience with it? I have yet to buy a turnigy product and it not deliver.

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