9
MTH 392E Operating Manual
TINPLA
TE
SELF-RECHARGING BATTERY BACKUP
ProtoSounds® state-of-the-art design includes a self-recharging battery backup system for
improved performance at any speed. The battery ensures that power to the sound system will
remain on during directional changes, setting RESET options or when travelling over dirty
track and switches. The self-recharging battery backup system is automatically turned on or
off whenever track power is turned on or are off. There no switches needed to enjoy the
benefits of the automatic battery backup system.
ProtoSounds® contains a warning alarm if the battery backup system fails to automatically
disengage when track power is turned off. Should the backup system fail, you will hear a
repeating whistle blast indicating this has occurred. Should this happen, unplug the battery
from the ProtoSound module (to prevent the battery from being run down) and contact MTH
for instructions on returning the tender for repair.
REPLACING THE PROTOSOUND® BATTERY
The ProtoSound® battery (located in the tender), is a special NiCad 7-cell, 8.4v battery -
NOT the 6-cell, 7.2v battery found in most convenience stores. The 6-cell NiCad is NOT
recommended for use with ProtoSound® applications. The battery is continually charged from
the track when power is applied and should last for up to five years. In addition, the NiCad
battery is a dry battery and should not leak or cause any damage to your locomotive during its
lifetime.
If you notice that the sounds seem distorted or garbled at low voltages or become silent when
power from the transformer is shut off, the battery may be losing its charge. Before replacing
the battery, you should put the engine in NEUTRAL and leave the transformer throttle set at
about 12 volts for 15 minutes. This should temporarily recharge the battery. If the garbled or
distorted sounds are reduced, then your battery charge has worn down. You can give your
battery a full charge by leaving the engine ON in the NEUTRAL position for 18 hours. (Make
sure the smoke unit switch is in the OFF position to prevent harm to the smoke unit wicking).
If you need to replace the battery, replacement ProtoSound® batteries are available from
MTH ProtoSound Electronics at 7020 Columbia Gateway Drive, Columbia, MD 21046. A
standard 9v alkaline battery can be substituted as a temporary fix, but since alkaline batteries
cant take a charge, it will eventually wear down. Regardless, it should give you a week to a
couple of months use while you wait for your replacement ProtoSound® battery to arrive.
