MI 2792 PowerQ4 Plus
Maintenance
135
Hazardous voltages exist inside the instrument. Disconnect all test leads
and remove the power supply cable before removing battery compartment
cover.
Use only power supply adapter/charger delivered from manufacturer or
distributor of the equipment to avoid possible fire or electric shock.
Rechargeable NiMh batteries type HR 6 (size AA) are recommended. The
charging time and the operating hours are given for batteries with a
nominal capacity of 2500 mAh.
Do not use standard batteries while power supply adapter/charger is
connected, otherwise they may explode!
Do not mix batteries of different types, brands, ages, or charge levels.
When charging batteries for the first time, make sure to charge batteries for
at least 24 hours before switching on the instrument.
7.2 Batteries
Instrument contains rechargeable NiMh batteries. These batteries should only be
replaced with the same type as defined on the battery placement label or in this manual.
If it is necessary to replace batteries, all six have to be replaced. Ensure that the
batteries are inserted with the correct polarity; incorrect polarity can damage the
batteries and/or the instrument.
Precautions on charging new batteries or batteries unused for a longer period
Unpredictable chemical processes can occur during charging new batteries or batteries
that were unused for a longer period of time (more than 3 months). NiMH and NiCd
batteries are affected to a various degree (sometimes called as memory effect). As a
result the instrument operation time can be significantly reduced at the initial
charging/discharging cycles.
Therefore it is recommended:
To completely charge the batteries
To completely discharge the batteries (can be performed with normal working
with the instrument).
Repeating the charge/discharge cycle for at least two times (four cycles are
recommended).
When using external intelligent battery chargers one complete discharging /charging
cycle is performed automatically.
After performing this procedure a normal battery capacity is restored. The operation
time of the instrument now meets the data in the technical specifications.
Notes
The charger in the instrument is a pack cell charger. This means that the batteries are
connected in series during the charging so all batteries have to be in similar state
(similarly charged, same type and age).
Even one deteriorated battery (or just of another type) can cause an improper charging
of the entire battery pack (heating of the battery pack, significantly decreased operation
time).
If no improvement is achieved after performing several charging/discharging cycles the
state of individual batteries should be determined (by comparing battery voltages,
