ETS-Lindgren HI-3627 ELF Magnetic Field Meter - Manual (Page 17)

HI-3627 Manual Page --9
Recharging
Recharge the battery with either the standard trickle charger or
the optional HI-3102 rapid charger. Recharging a fully
discharged unit will take 15 hours with the standard trickle
charger or one hour with the rapid charger.
The standard charger provided with the HI-3627 is a trickle
charger. It works by charging the battery with relatively low
current. The charger can be left connected to the meter
indefinitely without causing severe damage, although some
memory effects may result. NiCad "memory" sometimes occurs
when the battery is kept at full or nearly full charge without
intervening discharge cycles. The effect is to reduce the
apparent capacity of the battery and shows up as a short
operating time before recharging is required. This effect can be
minimized by occasionally operating the meter until the "Low
Battery" LED indicates recharging is necessary.
Charging time can only be reduced by increasing the current into
the battery. If the higher current is not carefully monitored and
stopped at the proper time, the battery will be permanently
damaged. The optional HI-3102 battery charger has been
developed in cooperation with a NiCad cell manufacturer to
charge the NiCad battery at it's maximum rate. This charger is
microcomputer controlled, and can safely recharge the NiCad
battery pack fully in one hour. The HI-3102 charger uses a
negative delta V algorithm to determine when the battery is fully
charged allowing a battery of any discharge state to be brought
to a full charge state without being overcharged.
There are a number of chargers available for this type of NiCad
battery pack. Some do a very good job of charging the battery,
but others sacrifice battery life for charge time. The HI-3627
should be charged only with approved battery chargers.