The usually missed clues that require battery attention:
1) Sounds quit the moment the reverse button is pressed.
2) Sounds quit much to soon after shutdown. Sounds should last a minimum of 10 seconds. Shorter times indicate that the battery is sagging below 7 Volts.
For either case, turn off the power and change out the battery.
Battery check:
For batteries that still seem to work but are past the 3 year age limit.
The 4 step battery test: with the battery plugged in and loco hooked up to a transformer (usually on the bench), take 4 readings: Volt meter must be able to read 9 Volts, with discernable 0.1 Volt increments.
1) Rest Voltage - no power applied, sounds are off.
2) Charging Voltage - Turn power on and note the reading, An increase (usually 0.2 to 0.4 Volts) shows that the battery is being charged.
3) Discharge Voltage - Turn power off and note the reading. A decrease is expected (about 0.1 to 0.4 Volts below the Rest Voltage reading).
4) After the sounds shut off and the battery circuit automatically disconnects, take the new Rest Voltage reading.
A good battery will return to the original rest Voltage reading.
A tired or somewhat discharged battery will be a little lower.
A really tired battery will not get back up to 8.4 Volts.
If any Voltage reading is below 8.4 Volts, either recharge the battery to see if things improve or replace the battery with a new one, recently charged.
Absolute minimum battery voltage under load (50 mA during power down cycle) is 8.4 Volts.
Most batteries charge up to around 9.3 - 9.5 Volts and don't drop below 9.0 Volts during discharge.
With any battery, it should be replaced after 3 years from installation.
It is considered prudent to put a sticker on the underside of the loco with the date of battery installation.
You may use the testing outlined above for detailed measurements to determine if it will have a chance of lasting longer.
Also see: MTH Battery Info.
After Market battery usage:
Due to an unusual interaction that can occur between the After Market Power Supply and a discharged battery (i.e. burning out), STR recommends a complete charging of the battery before each operating season. Failure to follow this recommendation could result in a burned out power supply.
See Battery check on the Battery Info: Battery Chg/AM & MTH SS page.
The revised charging schemes below assume that the Battery charging current limiter has been installed along with the proper battery:
If the Battery Charging Current Limiter has not been installed, substitute 14 Volts for the 8 Volts or Idle Voltage.
Beginning of season charging:
The track power must be 12 Volts or higher to prevent overheating of the power supply during the battery's initial hi current period. Allow 14 hours for the battery to be completely charged. It is best to have the loco on it's back or side, or sitting on a set of Jak Rollers
on the test bench while doing this procedure so it won't run away if a brief power interruption occurs.
Beginning of each operating session:
This technique is recommended for the start of the day's operation. Allow the loco to sit for 1-2 minutes at 12 Volts to top off the battery. The only battery to use is theMTH Ni-M-Hydrid green colored battery, along with the update to limit the charging current to a safe value for the power supply.
Foru different Charging setups:
1)
The easiest and safest way to achieve this, at minimal inconvenience, is to have installed an STR Battery Charging Current Limiter.
2) Note: MTH no longer supplies the Battery Charger kit.
MTH Proto1 Battery Charger Kit: $10, and operate it with an
MTH Proto2 Battery Charger: $15.
An STR Battery Charger adapter cable is available to make the interconnection easy between the After Market Power Supply and the MTH Battery Charger kit: $10.
STR's optional installation is $20.
When a deep recharge is necessary, just plug the MTH charger into the plug mounted in the underside of the loco, or wherever you put it.
All 3 items are in stock.
3)
For those who don't mind taking the shell off their loco, remove the battery and charge it in a commercial Ni-Cad battery charger capable of charging 9 V Ni-Cad batteries.
4)
Some batteries are held in with sticky foam tape. To avoid having to remove the battery and the subsequent replacing of the tape, obtain a 2' cable with battery snaps on both ends (offered by STR: $15) to act as an extension cord for connecting a battery to a battery charger. With this tool, one can leave the battery in the loco while it is being charged by a commercial battery charger.
Make your own extension cable:
If you make your own extension cable, find 2 battery snap cables (can be obtained from Radio Shack) wire them with an appropriate length of wire, slip on heat shrink tubing or leaving bare for use of electrical tap after the test below, connecting the black lead from one end to the red lead on the other and visa versa.
Test with an Ohm Meter or continuity checker to make sure the male snap at one end is connected to the female snap at the other, and visa versa. Very, very occasionally, the black and red wires are reversed on one snap. When the unit tests correctly, shrink the tubing or complete the tape wrap.
WARNING:
Do not use the After Market sound systems with non-linear waveform transformers until each After Market Power Supply has been updated by STR. To use them without the upgrade in such an environment can cause them to burn out, within seconds of operating.
The currently known Non-linear waveform transformers:
See: Transformers
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