Windy Nation 100 AMP DC Watt Meter - Manual (Page 10)

Watt Meter User Manual
Revision 1.0
After connecting the LOAD to the meter, connect the battery. Discharging begins when the battery is
connected.
When the battery is discharged, the meter display indicates the total charge (Ah) and energy (Wh) the
battery delivered to the load as well as the peak Amps (Ap) and peak Watts (Wp) used and the minimum
voltage on the battery during the discharging process.
5.3.2.1 Battery Efficiency
Battery Charging Efficiency (BCE) is the ratio of energy put in to energy removable.
Charging Efficiency = Discharge Energy ÷ Charge Energy.
Efficiency is never 100% due to a variety of losses involved. If the charge energy was 15 Wh and the
discharge energy is 14.2 Wh the Charging Efficiency is: 14.3 ÷ 15 = 0.95 or 95%
BCE depends on both the charger and the battery so it can be difficult to determine where problems are
without extra batteries or chargers.
5.3.2.2 Battery Health
Battery Health is determined by comparing the actual energy or charge capacity with the manufacturer's
specifications or a "new" battery as a reference. Since it can be difficult to get manufacturer specifications to
match test results, it is often simpler than and just as useful to record the capacity value of a "new" battery
and save that as a baseline. Note that a "new" battery may be defective and give out of specification results.
By occasionally discharging a battery pack and comparing the energy delivered to the baseline value
delivered when it was first put into service, you can track that battery's health. The percentage of baseline
capacity at which a battery is considered to be at the end of its life depends on battery chemistry and how it
is used. A reduction in charge capacity can also be an indication of battery pack damage or imminent failure.
To summarize, the percentage of baseline or initial capacity indicates a battery's health.
Baseline Capacity Ratio = Current Capacity ÷ Original Capacity
5.4 S YSTEM C HARACTERIZATION
It can be very difficult to find out why a component fails. The Watt Meter’s ability to capture even brief
current/power peaks and voltage minimum values can help.
The Peak Amps, Peaks Watts and Voltage Minimum values will be the peaks and minimum captured
following the meter’s power on sequence. Be careful in adjusting test setups to not accidentally cause a 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.
The meter’s Peak Amps, Peaks Watts and Voltage Minimum values are cleared whenever the meter is
powered up, so remove all power sources when you need to clear them for a new measurement.
6 TROUBLESHOOTING AND SUPPORT
The Watt Meter is ruggedly constructed and requires minimal care. There are no adjustable or field
serviceable parts inside. The case is welded shut and cannot be opened without damage. Opening the case
will void the warranty.
6.1 C ARE
To clean your meter, moisten a cloth with a few drops of mild hand dishwashing detergent in a cup of
lukewarm water and gently wipe clean. Do not exert too much pressure on the display as this can
permanently damage it.
Store your meter in a safe place where it is protected from impact and scratches to the LCD display. Do not
store in direct sunlight. Prolonged exposure (years) to direct sunlight will break down the plastics.
Page 10 of 11 Windy Nation 04/19/2012