NDX40 User’s Manual
Xenotronix/TLI
2
INTRODUCTION
The Model NDX40 is designed with the best
interests of your battery in mind. It is a high
reliability battery charger designed for
recharging Nickel-Cadmium (NiCd) and
Nickel-Metal-Hydride (NiMH) batteries. It
can charge from 1 to 12 cells at currents from
500 mA to 2500 mA. Accurate detection of
fully charged batteries is accomplished using
negative-delta-V sensing with 12.5-bit resolution, digital filtering, currentless voltage
sensing, and a nominal –0.5% (with respect to top level) negative-delta-V detection level.
To prevent the false detection of negative-delta-V, the sensing circuit is inhibited at the
beginning of the charge cycle. The back-up timer is matched to four charging rates: 2C
(45 min), 1C (1.5 hr), 0.5C (3 hr), and 0.25C (6 hr).
An optional temperature sensor can be used to detect when the battery temperature falls
outside of the safe range of 0 ºC and 50 ºC. Outside the set temperature range, float
charge takes place and the back-up timer is paused. A built-in hysteresis (offset) prevents
rapid on/off cycling. When the battery temperature returns to a safe range, the charger
resumes where it left off. This option is recommended for the quicker 2C and 1C charge
rates to minimize the effects of overcharging.
When charging is complete, the charger will enter a float charge mode where a lower
current is pulsed to avoid cell degradation due to dendritic (crystalline) growths.
This unit incorporates protection against open circuit batteries, during which time outputs
are switched off and timing is reset.
There is a single yellow LED indicator that comes on solid during charge and flashes
when the battery is charged and ready for use.
Equipped with a thick aluminum heat-sinking chassis to ensure field reliability and
performance, the NDX40 is designed to withstand rugged applications. An IEC-60320
input module and switchable input power are provided to enable the maximum flexibility.
The standard output cable is three feet long and has a barrel plug connector. An optional
four-conductor cable with a thermistor is offered for wiring to a custom connector – the
included temperature sensor must be built into the battery pack. We also offer an optional
temperature probe on a secondary cable that can be added to monitor the external battery
pack temperature.
OPERATING INSTRUCTIONS
Before using this battery charger, make sure that it is compatible with your battery. Refer
to the battery charger, the specifications in this manual, and your battery documentation.
