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Battery Watch

A picture of the Battery Watch Unit

*            Connects to a 12 Volt Battery


*            Prevents Deep Discharge


*            For Solar & Fuel Cell Batteries


*            Optional Latching Alarm Relay


The Xtronix Battery Watch is designed to prevent deep discharge in Lead Acid Batteries by disconnecting the load when the battery voltage reaches a preset value. A Lead Acid battery can be permanently damaged if a load is left connected to it which causes the battery to discharge completely (deep discharge).


To maximise battery life, the load should be disconnected from the battery when the battery voltage reaches the battery manufacturer’s recommended ‘cut off’ voltage. The actual ‘cut off’ voltage is affected by the battery construction and the battery loading – refer to the battery manufacturer’s specification to determine the optimum cut off voltage. The voltage at which the unit disconnects the load can be preset prior to connecting the unit to a battery and load.


The Xtronix Battery Watch can also be supplied with an optional latching relay that can be set by an external alarm signal. Once set, the latching relay stays set even if the power is removed from the unit. This is intended to provide a permanent alarm state for telemetry systems. The latching alarm output is presented as a change over contact (NO-COM-NC). It is cleared when the reset button is pressed.





Nominal Input Voltage                            12 volts DC (e.g. typical Lead Acid Battery Voltage)

Maximum Input voltage                          16 volts DC (allows for battery charging)

Maximum Load Current                          10 amps DC (NOTE: user must provide external 10A fuse)

Battery and Load Connectors                 2 Way Screw Terminal – wire size 21 AWG to 14 AWG

Latched Alarm Relay Input Connector      2 Way Screw Terminal – wire size 30 AWG to 16 AWG

Latched Alarm Relay Output Connector   3 Way Screw Terminal – wire size 30 AWG to 16 AWG

Latched Alarm Relay Actuating Voltage   12 volts @ 15 mA (800 ohm coil) – other voltages available

Latched Alarm Relay Contact Rating       1 amp at 24 volts resistive (30 volts DC Max)

Temperature Range                                0 to + 40°C

Humidity                                                + 5 to + 80% Non Condensing

CE Marked                                            Yes – Safety, EMC, ROHS and WEEE


Ordering Information                            Xtronix P/N

Battery Watch                                        551/9001

Battery Watch with 12V Latching Relay 551/9001 LA12V

Download Datasheet Button

For pricing and delivery email sales@xtronix.co.uk

NOTE: Description and specifications may be changed without notice



Copyright © Xtronix Ltd. All rights reserved. Jan 2021 - Rev 10