Greg Covey

Hi,

I'm reviewing the new "Watt's Up" watt meter from [link=http://www.rc-cars-planes.com/rc-battery-watt-meter.html]RC Electronics[/link].

The "Watt's Up" RC battery Watt meter measures and calculates all the electrical parameters you need to get high performance from your R/C cars or planes. It is essential for increasing the performance and safety of your electric-powered R/C model. With the best balance of specifications and features on the market, you can stop guessing and start knowing "Watt's Up" with your plane!


Why do I need a watt meter? The "Watt's Up" R/C battery watt meter helps you:
* Predict model airplane flight time
* Ensure peak currents are safe for motor, wiring and connectors
* Check battery health and whether battery should be retired
* Evaluate R/C battery charging efficiency
* Verify that the minimum voltage while operating is within specifications
* Choose the best propeller or gearing and the most efficient motor
* Check for wiring and connector power losses
* Measure power and energy consumption of ANY device with a battery

Greg Covey

Key Features of "Watt's Up" power analyzer

* Measures energy (Wh), charge (Ah), power (W), current (A) and voltage (V)
* Connector to use a receiver battery for measurement down to 0 V
* Captures current peaks and voltage minimums(droops)
* Accurate & precise - 0.01 A current and 0.01 V voltage resolutions
* Rugged - handles 50 A continuous and 100 A peak at 60 V
* 14 ga., 7 x 37 stranded, high temp silicone rubber insulated wire without connectors
* Small & Light: 2.8" long x 1.7" wide x 0.83" thick (70 mm x 44 mm x 21 mm), 2.5 oz.
* Acts like a wire so doesn't affect model's performance. Precision current sensing resistor, with only 0.001 Ohm resistance and circuitry only draws 0.007 Amps
* Uses DSP to increase ADC resolution and differential measurement amplifiers to increase noise immunity
* Factory calibration stores constants in EEPROM to compensate for component tolerances
* One Year Warranty
* Complete User Manual

[/b]Specifications:[/b]
* Voltage 0-60 V, resolution 0.01 V. That's a 14 cell series li-poly pack!
* Current 0-100 A peak, 50 A continuous, resolution 0.01 A
* Charge 0-65 Ah, resolution 0.001 Ah. That's ~32 Amps for two hours!
* Power 0-6500 W, resolution 0.1 W. That's ~8.7 Horsepower!
* Energy 0-6500 Wh, resolution 0.1 Wh. That's lifting a 50 pound model into outer space (65 mi.)!
* Operates from 4.0-60 V, 0 V with optional receiver battery pack
* 16 x 2 STN LCD display
* Powerful, 8 MIPS micro-controller

The "Watt's Up" watt meter comes with a manual but without connectors. I soldered a set of Dean's Ultra connectors onto my meter for testing in a variety of applications.

Greg Covey

I've been using other watt meters for years like the popular Astro Flight "Super" and "Micro" whattmeters. The single "Watt's Up" watt meter can not only perform the range of both Astro Flight meters but can even go beyond it for specifications not before seen in any other unit.

Since the "Watt's Up" watt meter can use an external receiver battery, it can measure a voltage range from 0-60v with a 0.01 volt resolution and a current range from 0-100amps with a 0.01 amp resolution. Now, even single-cell Lithium power applications can be measured.

Greg Covey

Here are some sample measurements I took on a power system that draws around 15amps.

The first screen shown of the alternating LCD display can capture current peaks and voltage minimums (or droops). It also measures energy used (Wh) and power in watts (W).

The second and third screens show the same display alternate at different times. The charge level (Ah), power (W), current (A) and voltage (V) are all shown. Only the power in the lower right corner keeps the same units.

The "Watt's Up" watt meter has been optimized for the needs of the R/Cer with added features like charge display in Ah and power in Wh. Conventional equipment like a DVM often has insufficient current range and too much insertion loss due to internal resistance or long leads.

Greg Covey

My next test of the "Watt's Up" watt meter was to verify the voltage measurement against a Fluke 79 series multimeter. I measured 0.01v difference which was probably exactly correct since my Fluke meter was tapped at the output conector side after about a 6" wire length.

rm

My Feedback: (27)

Could you expand on the capture capability. One gripe I have with the astro is trying to read it while holding on to the model with one hand and running the tx with the other. Makes it hard on larger models.

Greg Covey

rm,

It can be very difficult to hold the watt meter while holding the plane and transmitter. On larger planes, the prop wash blows the watt meter so you can't see it sometimes. The Watt's Up ability to capture even brief current peaks and voltage minimum values can help.

The Peak Amps value and Voltage Minimum values will be the peak and minimum
captured following the Watt's Up power on sequence. Be careful in adjusting test setups to not accidentally cause a current peak or voltage minimum that isn't the one you are watching for. This might happen if, for example, you connect another component to the
system while it is measuring. When you throttle back down, your peak current reading and lowest voltage reading will be maintained until you disconnect the flight pack.

The Watt's Up's Peak Amps and Voltage Minimum values are cleared whenever the Watt's Up turns on (i.e. is powered up). So remove all power sources when you need to clear them for a new measurement.

StephenT

Greg,


My wattmeter is the best birthday present I ever got!

Sparhawk

Greg - I was in the market for a good meter and looked at buying on of the Astro meters, but after dropping in at RC Electronic's website, I just had to part with a little Christmas loot.
Should be here for the New Year!!
It's going to be as valuable as a RPM and Temp meter and will make a great addition to my 'Tweaking' toolbox.

Spar

Greg Covey

Stephen,

Good to know. Hopefully, you're still young yet.

Spar,

I agree. I've been using multiple wattmeters between my larger glow conversions and micro-flight projects. Now I can use just one wattmeter for everything.

Here is another application that comes in handy for the lower-end chargers. You can monitor the charge that you put back into the pack and keep a closer eye on the actual current being applied to the pack. I love the inexpensive Apache 2500 chargers for 1-4 cell Lithium packs but often want to measure just how much I depleted the pack after a flight. The "Watt's Up" watt meter allows me to do it if I reverse the connector sex by using adapters. Shown here is an already charged 2-cell Kokam 1500mAh pack that I am just tweaking up to 8.4v.

Greg Covey

When I measured the power on my new ProJeti wing with the "Watt's Up" watt meter, it confirmed my suspicion with an eyebrow raising 43amps and 440watts! The finished wing not only balanced perfectly with the new 3-cell Kokam 3.2AH pack but the Lithium pack held a higher voltage at 43amps than any other pack I own.

The flight test should be fun and will either be my fastest ever hopup or will blow the motor out from the high power. In either case, I'll have a documented reading to refer back on.

rrw71

My Feedback: (5)

Can I use this instead of an ESV?

Greg Covey

What is an ESV?

Matt Kirsch

My Feedback: (21)

Expanded Scale Voltmeter. You use it to check the condition of your receiver batteries, if your plane is so equipped.

No, you can't use this tool in place of an ESV. The ESV puts a load on the receiver battery to check it's REAL condition.

I suppose you could connect it between your receiver battery and receiver to see how much current the servos draw while you're flying, though...

rrw71

My Feedback: (5)

The more I looked at the product, It would be best suited for electric motor applaications. I thought about installing like an onboard rx battery meter. Then I would know exactly what was left. Little expensive for that application though.

Thanks,

Rob

Greg Covey

Rob,

I agree.

Matt,

Thanks for the information but what's a receiver battery?

rrw71

My Feedback: (5)

Sorry. This probably isn't the right forum for this discussion.

Greg Covey

Rob,

You're fine here with your questions.

We need to learn glow stuff too. Luckily, our friend Matt goes both ways!

P.S. Matt, I'm demo flying for the field house director at RIT on Friday. We may be moving to a huge indoor site soon.

rx8

Guys,

I'm new to RC and have been flying 4 mos. I now own
4 planes; TM400, Gypsy, J-3 Cub and a Hanger 9 Arrow.
My electric planes have JST type connections, What type
of connectors do I need on the Watts up meter?

Thanks,
Ron

Diggidy

RX8,

I have the Watts Up meter and love it.

It comes without any connectors attached to the wires. Whatever connector it is that you like to use that is the one that you solder on.