Powering the VFC400-WiFi
VFC400-WiFi User Guide
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Powering the VFC400-WiFi
The VFC400-WiFi is designed to be supplied via its USB socket from a commercially available 5V USB power
supply (5W). When supplied externally, the power symbol shows on the display:
Some low-quality USB power supplies are unable to deliver sufficiently stable power to the VFC400-
WiFi. Please use a power supply from a reputable source that carries the UL or CE marking.
If the logger detects an unstable power source, the power symbol will flash and the buzzer will
sound.
In this case, the logger will not be powered by the external supply, but remain powered by the AAA
batteries instead. Please remove the supply and replace it with one of better quality.
When you remove the external USB power the display briefly turns off.
The VFC400-WiFi also uses two internal AAA batteries as a backup should external power be unavailable, for
example in the event of a power cut. If used as a backup, the batteries have a life span of approximately 6 to 12
months, depending on the time the unit operates without external USB power.
Running the VFC400-WiFi solely without an external supply is possible, but not recommended, as it will deplete
the AAA batteries in around 2 to 3 months and also shorten the life of the secondary backup battery.
The rate at which battery power is used largely depends on the signal strength of the wireless network signal,
with a weaker signal draining the battery faster. A short log interval, viewing data on the display frequently and
sounding the alarm often will also reduce battery life.
The batteries inside the unit will not be charged when external power is supplied.
A 4-bar battery indicator shows an approximate remaining battery capacity. If the batteries are full, this symbol
will be shown:
When the batteries are empty, this symbol will be shown, and the batteries require replacement.
Please always replace both batteries with fresh ones at the same time. Replacing only one of the
batteries with a partially charged battery will drain the secondary backup battery.
Rechargeable AAA cells are not recommended for this product. The different charge voltage means
the battery indicator will not show the correct remaining percentage, and the secondary backup
battery will drain faster.
