EASY
SENSE V-Log Reference Manual
DO248 (5)
20
Data Harvest Group Ltd, 2014
Powering V-Log
EASY
SENSE V-Log can be powered by:
1. The USB port (whilst connected).
2. Its internal batteries (when charged).
Connect V-Log directly to a USB port on your computer*, or a USB mains charger**, or a powered USB
hub***, using the USB cable supplied. A full charge can take up to 8 hours.
A battery charging symbol will be displayed on V-
Log’s screen while the logger is charging.
Notes:
*Your computer must be turned on and not in sleep or standby mode; otherwise, the battery may drain instead of
charge.
** USB mains charger that outputs 5 V at 1 A or more.
***V-Log can only be connected directly to a computers USB port or by using a
powered
USB hub. It will not
work with an unpowered hub (V-Log requires an output current of 500 mA).
An extension cable must be of a single direct port extension type.
While V-Log is accepting power or in WiFi or Bluetooth mode it will not operate auto switch off.
When used in WiFi mode it is recommended that V-Log is connected to a power supply as the power
requirements are high, and will drain the battery quickly.
If using intending to use V-Log in Bluetooth mode powered by its battery, fully charge the battery before
use e.g. leave to charge overnight for use in lessons the next day. When the battery is in good condition
and fully charged it will power a Bluetooth connected V-Log for about 8 hours.
Batteries
V-Log is fitted with a rechargeable lithium-ion battery pack. Whenever V-Log is connected to the USB port
on the computer, it will automatically re-charge the battery.
Lithium-
ion batteries are ‘memory-free’ and prefer a partial rather than a full discharge. Constant partial
discharges with frequent recharges will not cause any harm. Frequent full discharges should be avoided
whenever possible.
Ideally V-log should be stored at about 40% or more charge. Do not
store V-Log with its battery fully
discharged or with sensors connected. Even when turned off (asleep), V-Log will use a small amount of
current, and the battery will slowly discharge (some reserve charge is required to retain data and settings
in memory). If V-Log
is to be stored for lengthy periods without use then it’s a good idea to recharge the
battery every 6
– 8 weeks.
When its battery is in good condition and fully charged it will power V-Log in EasyLog or remote mode for
a minimum of 41 days.
The speed at which a lithium-ion battery will age is governed by both its storage temperature (preferably
less than 40ºC) and state-of-charge. Ideally batteries should be replaced every 4 years. Eventually the
battery pack will no longer deliver the stored energy and will need to be replaced. A fully charged battery
that loses its charge quickly or a battery with symptoms of swelling or physical damage will demonstrate
the need for replacement. When this happens, contact Data Harvest and request a battery replacement
pack for
EASY
SENSE V-Log
Auto switch off
While battery powered V-Log will normally auto switch off (go into low power sleep mode) to reduce
power consumption if more than two minutes have passed since any measurements have been taken or
a button was pressed.
If V-Log is accepting power or in WiFi or Bluetooth mode it will not operate auto switch off.
V-Log will wake up when any button is pressed.
While remote recording on battery power in EasyLog mode or after using Setup Remote, V-Log will
stay awake until the interval between readings reaches 5 seconds or greater
– at this point it will begin
to use sleep mode between samples (waking up just in front of the sample time to allow the sensors to
stabilise).
