VE6AB Mobile Ops
DC Inline Watt Meter and Power Analyzer
I recently acquired this device from a fellow ham, and I hadn't got around to checking it out until now.
Its proving to be a handy device to have for all the right reasons.
This meter is sold through various sources, including Power Werx, Byonics, and West Mountain Radio as well as others, and I suspect that they are all the same units, although possibly labeled differently.
There are more elaborate and expensive meters out there that do much the same thing, but this meter gives you a lot of bang for the buck.
In this photo I have this inline watt meter/power analyzer in line between the main battery (SOURCE) mounted in the engine bay of my mobile, and the 12 volt DC to 110 volt AC inverter (LOAD) mounted beneath my radio stack, with a 110 volt AA battery charger plugged in to it.
Just so you know, I had just started the engine in my mobile when I shot this photo, and In this case the battery charging voltage is 14.62 volts with the engine at a fast idle. The radio stack amongst other accessories had been in play for several hours or more before my having started the engine.
This meter in line with the charging system makes it easy to monitor the charging system, and within a few minutes as the batteries come up to charge, the charging rate drops off as expected.
The charging rate will then vary depending on the load on the batteries.
I am running 2 AGM crank batteries in the engine bay of my mobile, and the batteries will get a quick full charge recovery after starting as required.
If the charging rate were 14.8, that would start to be a worry, but 14.6 is fine with 14.2 to 14.4 the norm while driving depending on what accessories are in play.
I also know these readings are accurate, as I have a voltage meter permanently mounted in the engine bay, and it mirrors the 14.62V reading on this meter.
When I initially installed the under-hood meter in the engine bay, I checked these readings with my Fluke meter confirming the accuracy of the meter.
This watt meter is designed for systems using less than 60 V and carrying currents up to 130 A.
Some of the capabilities for this watt meter....
The meter measures eight parameters that are essential to electric power safety and performance. Use it to prevent peak currents from damaging a battery. Motor control, motors, wiring and connectors. Set cutoff voltages, check battery capacity & health. Balance battery cells, Confirm proper battery charger operation.
Inline DC Meter
You can think of the watt meter as a set of jumper cables. Connect it in the same way and you can measure what the jumper cables are connected to. Like jumper cables, the watt meter is essentially a direct connection between the source and load. For example, both the source and load leads are electrically "hot" when a battery is connected to either side. Current flows from source to load.
Display Screen
Each time power is applied across the watt meter, a startup screen with logo is briefly displayed and peaks, minimums, Ah & Wh are reset to zero. Then the display changes to the measurements screen.
The measurement screen continuously displays Amps, Volts and Watts. All other measured values are presented sequentially, every second, in the Data-Queue position of the display. Data values are identified by their units (Ah, Wh, Ap, Vm, Wp). All measurement screen values are updated every 0.4 seconds.
The Measurement Screen layout: Amps, Volts, Watts & "Data Queue". The "Data Queue" shows Ah, Wh, Ap, Vm, Wp in sequence.
Current: Amps & Peak Amps (A, Ap)
Only current from source to load is measured. Amps values displayed are the average current over the last screen update interval. Peak Amps value (Ap) displayed is the maximum current drawn from the load side, since the meter's startup. Peaks lasting only a fraction of a second, can be captured. Supplying auxiliary power with a voltage greater than the meter is measuring removes the meter's operation current from measurements.
Voltage: Volts & Minimum Volts (V, Vm)
The displayed Volts value is the average voltage over the last screen update interval. The displayed Minimum Volts value (Vm) is the minimum voltage (or "sag") measured on the source side, since the meter's startup. The Volts value is measured on the source side.
Energy: Watt-hours (Wh)
The displayed value is the total energy delivered in Watt-hours since the meter's startup. It is measured on the load side.
Charge: Amp-hours (Ah)
The displayed value is the total energy charge in Amp-hours (x1000 = mAh) delivered since the meter's startup. It is measured on the load side.
Power: Watts & Peak Watts (W, Wp)
The displayed value is the average power delivered in watts (=Volts * Amps) over the last screen update interval. The displayed Peak Watts value (Wp) is the maximum power drawn on the load side since the meter's startup. Watts values are measured on the load side.
So to sum up what I have learnt since first familiarizing myself with this meter, and having used it over the course of a week, I believe a meter of this sort has a place in every ham's kit.
On a final note, I use powerpoles on everything, and as noted, I have powerpoles installed on this meter making it convenient to place it in line with my various devices for monitoring purposes.
