Watts Up Meter

Track power usage, voltage and current with a Watts-Up meter

Available in the USA for around $60 (and around GBP 45 in the UK), the Watt's Up Meter and Power Analyzer (model WU100 version 2) is a combined ammeter, voltmeter, wattmeter, and battery capacity meter. The Watt's Up meter can either be powered by an auxiliary battery, or in 4+ Volt applications draw power (just 7 milliamps) directly from the main battery in the circuit being analysed. The Watt's Up Meter is manufactured in the USA by RC Electronics, Inc. (1).
NEW - Click here to buy a Watts Up Meter in the UK (2), or here to purchase direct from USA (3) at below recommended retail price.

The Watt's Up Meter was designed primarily for use by radio control enthusiasts - for example to track the power usage of RC aeroplanes etc. However it has many useful applications in renewable energy system applications (particularly the Doc Wattson R102 variant discussed later in this article). The meter is simply connected between the battery bank (4) and the load - for example a power inverter (5).

The Watt's Up meter is just 2.8 x 1.7 inches in size and 0.83 inches in thickness, and has a built-in 0.001 Ohm Shunt (6).

Power connector cable for a Watt's Up power meter or a Doc Wattson R102 model

It is sold without connectors so you are free to choose how to use and power the meter. However suitable connectors (pictured above) are available for a few dollars at the time of purchase.

Watt's Up Meter Specifications

Parameter Range Resolution Voltage 0-60 V* 0.01 V
Current 0-100 A 0.01 A
Power 0-6500 W 0.1 W
Charge 0-65 Ah 0.001 Ah
Energy 0-6500 Wh 0.1 Wh

DOC Wattson R102 Digital Panel Meter

Pictured above is a variant of the Watt's Up Meter - the DOC Wattson R102 Digital Panel Meter. The Doc Wattson R102 is basically the same as the Watt's Up model WU100 pictured above, but it has been modified to measure systems which maintain high currents for long periods of time - therefore making it perfect for renewable energy systems.

The Doc Wattson R102 is particularly useful for measuring the health of both individual batteries (7) and 12V, 24V, 36V, or 48V battery banks. Battery charging efficiency (BCE) is measured comparing the discharge energy to the charge energy, and battery health (baseline capacity ratio) is calculated by comparing its charge capacity with the battery manufacturer's specifications (entered by user).

DOC Wattson R102 Meter Specifications

Amp-Hours: (0 - 6554)
Kilo Watt-hours: (0 - 650)
Amps: (0-100 peak)
Watts: (0 - 6554)
Peak Amps & minimum Voltage ("sags")
Voltage: (0 - 60)

Connecting the Doc Wattson R102 into a renewable energy system is very easy. Click here for some R102 Connection Diagrams (8)

Watt's Up Meter and Power Analyzer User's Manual

The comprehensive 31 page Watt's Up Meter and Power Analyzer User's Manual (9) is available here (PDF).

Watt's Up Meter Online Similation

An online simulation of the Watt's Up Meter in action is available on the RC Electronics website by clicking here: Watt's Up Simulator (10). The simulator is based on an RC application, but it gives a good idea of the data displayed by the Watt's Up meter when it is connected into a circuit.

Web Link References

(1) http://www.rc-electronics-usa.com
(2) http://rover.ebay.com/rover/1/710-53481-19255-0/1?type=3&campid=5335956244&toolid=10001&customid=watts+up+meter&ext=watts+up+meter&satitle=watts+up+meter
(3) http://rover.ebay.com/rover/1/711-53200-19255-0/1?type=3&campid=5335956244&toolid=10001&customid=watts+up+meter&ext=watts+up+meter&satitle=watts+up+meter
(4) http://www.reuk.co.uk/Interconnecting-Batteries-for-Battery-Bank.htm
(5) http://www.reuk.co.uk/Power-Inverters.htm
(6) http://www.reuk.co.uk/What-is-a-Shunt.htm
(7) http://www.reuk.co.uk/storage.htm
(8) http://www.rc-electronics-usa.com/ammeters/3-wire-meter-connection.html
(9) http://www.powerwerx.com/techdata/Watts-UP-V2.pdf
(10) http://www.rc-electronics-usa.com/ammeter-simulator.html