Operating On The Battery; Recharging The Battery - Promax MC-377+ Instruction Manual

INSTRUCTION MANUAL MC-377+.

3.2 Operating on the battery

The MC-377+ is a portable device powered by a 12 volt internal battery. Before
taking any measurements, the battery charge must be checked. If the battery is low (a
voltage lower than 11.2 V) colon sign (:) will appear blinking on the display of the
frequency counter, under this circumstance the equipment must be connected to the
mains to carry out the battery charge.
For the device to operate on the battery, disconnect the power cord and press the
start switch I/O [3].
If the battery is very low, the cut-off circuit will prevent the device from functioning. In
such a situation the battery must be recharged immediately.

3.2.1 Recharging the battery

The MC-377+ has an incorporated battery-charger which can be directly connected
to the mains. Battery charging can take place during the normal working day. The
instrument may still be used while the battery is being charged, under these conditions
the battery will charge to up to 90% of its capacity.
To recharge the battery, connect the device to the mains supply without pressing
the start switch I/O [3]. The length of time it takes to recharge depends on the condition
of the battery. If it is very low (the low battery message appears) recharging period is 7-
8 hours. The indicator light LINE [16] should remain lit.
The battery charge must always exceed the minimum cut-off charge.
To ensure the best results, the lead battery in this device must always be fully
charged. If the equipment has been in storage or used only occasionally for a
long period of time, it is ABSOLUTELY NECESSARY to check the full-charge
functions periodically (every six months, for example), and to compensate for the
self-discharging effect of the battery. The rate at which a fully charged battery
self-discharges depends on the temperature. For example, at an ambient
temperature of 20 ºC, the battery suffers a 50% loss after 16 months and at 40 ºC
it loses the same charge in only 5 months (these are reference data). If the battery
remains very low for a period of 4 weeks or more, it will not accept recharging
since the plates are sulphated and must be replaced.
May 2001
IMPORTANT
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