Rechargeable Battery Management Guidelines - Minelab F Series Operation Manual

F Series Battery Charger Operations Manual
15.

Rechargeable Battery Management Guidelines

Battery Management
Ideally, NiCd and NiMh batteries should be frequently used to get maximum
life from them. If properly charged and used (regularly fully discharged to
'Battery Low'), a life of 2 to 5 years can be realistically expected.
All references to NiCd batteries in the following text also apply to NiMh
batteries.
Batteries must be kept in the same sets of 4 during charge and use, this is the
single most important factor for efficient rechargeable battery management.
(This can be easily accomplished by numbering the batteries by set.)
batteries with unequal levels of charge are mixed, the following problems can
be expected:
•
During use, after the battery with the least charge is fully discharged,
power is drawn from the remaining batteries until the detector low
battery alarm is triggered. During this period, power passing through
the discharged battery may force it into reverse polarity, and some
damage to the battery will occur.
•
During charging, depending on the charger and charge state of the
individual batteries, not all batteries may be fully charged, or some
batteries will be overcharged. If all the batteries are not fully charged,
discharge time will be shortened. When NiCd batteries are
overcharged they overheat and suffer some damage.
Every time a NiCd battery is overcharged or discharged to the point of reverse
polarity, some damage to them will occur. Therefore if NiCd batteries are
continuously mismanaged, their working life will be significantly shortened.
Storage and use in very hot (over 40 deg C), or very cold (less than 5 deg C)
temperatures will also shorten battery working life.
Minelab supplied NiCd batteries should be fully discharged at least once a
month. This can be achieved by either using them in the detector until Battery
Low alarm is triggered, or using the discharge function on the F Series
Charger. One discharge/ charge cycle using the F Series Charger will take
approximately 12 hours per set of four batteries.
Additional notes:
Self discharge: NiCd batteries slowly lose their charge during storage. The
rate of self discharge depends on environmental conditions (not too hot or
cold), condition of the battery (new or well managed batteries will self
discharge slower) and charge state of the batteries (fully charged batteries will
If