Why Choose the BCR?
Not all battery replacements are the same.
Alternative battery-replacement circuits are available for model railroad locomotives, but there are important differences in construction, capacity, protection and performance.
J&W Electronics developed the BCR as a permanent replacement for troublesome locomotive batteries. This page explains the differences J&W has identified between the BCR and alternative replacement circuits, including results from electrical testing.
Compare the Difference
BCR vs. alternative replacement circuits
The differences go beyond the purchase price. Fit, electrical capacity, voltage rating and protection from overcharging can all affect how a replacement circuit performs in your locomotive.
BCR
- Circuit is installed in a nine-volt battery case and fits in the locomotive's battery holder.
- More than 165,000 units in service.
- Rated at 10.8 volts.
- Designed for use in Proto-Sound 1 and compatible Proto-Sound 2 applications.
- Each capacitor is protected from overcharging by a Zener diode.
- Recommended by M.T.H.
- 750,000 microfarads, or 0.75 farad, of capacitance.
- 50% greater capacitance than a 0.5-farad alternative.
Other Replacement Circuits
- May be shrink-wrapped or enclosed in a case with additional wires and a connector.
- Some units do not fit the original battery bracket and must be secured another way.
- Some applications may require modification, and the circuit may not fit in some locomotives.
- Products examined by J&W were rated at 10 volts.
- J&W reports that PS2 locomotives can charge the circuit to approximately 10.4 volts.
- Products examined by J&W did not provide individual overcharge protection.
- Highest capacitance in the products compared by J&W was 500,000 microfarads, or 0.5 farad.
Capacity Matters
More capacitance means more stored energy.
Capacitance is measured in farads. The BCR has 750,000 microfarads, or 0.75 farad, compared with 500,000 microfarads, or 0.5 farad, in the alternative circuit used for J&W's comparison.
That gives the BCR 50% greater capacitance. The larger capacity takes somewhat longer to charge, but J&W's testing shows that it retains substantially more voltage after track power is removed.
Electrical Testing
See the results for yourself.
J&W Electronics performed electrical tests comparing the BCR with an alternative battery-replacement circuit. During charging, the higher-capacity BCR takes slightly longer to reach the same voltage. After track power is removed, however, the BCR retains considerably more voltage.
| Test Point | BCR | Alternative |
|---|---|---|
| Track Power Applied | ||
| After 30 seconds | 8.25 V | 9.00 V |
| After 45 seconds | 9.00 V | 9.25 V |
| After 60 seconds | 9.70 V | 9.90 V |
| Track Power Turned Off | ||
| Immediately after power is turned off | 8.55 V | 8.25 V |
| After 30 minutes | 7.29 V | 6.14 V |
| After 1 hour | 6.50 V | 4.30 V |
| After 2 hours | 5.27 V | 2.88 V |
| After 3 hours | 4.40 V | 0.84 V |
| After 4 hours | 3.40 V | 0.28 V |
What the Test Shows
The difference becomes clear after the power goes off.
The alternative circuit initially charges slightly faster. Once track power is removed, the BCR's greater capacitance allows it to retain more voltage for a longer period.
J&W designed this additional stored capacity to provide more power for the locomotive's sound system during shutdown.
Compare the Value
Price is only part of the comparison.
Comparing cost per farad provides another way to look at the difference between the products.
0.75 farad
J&W shipping: $8.00
0.5 farad
J&W has also seen component kits offered for approximately $16.00 plus $11.00 shipping and handling. These require assembly by the purchaser.
By comparison, the BCR is completely assembled and ready to use for $24.95 plus $8.00 shipping.
Quantity discounts can reduce the BCR price to as little as $22.68 each. See the Pricing page for current quantity information.
The J&W BCR
Designed as a complete battery-replacement solution.
The BCR combines 0.75-farad capacity, overcharge protection, convenient installation and proven operation in a completely assembled unit.