Why M.T.H. Uses NiCad Batteries and When to Replace Them Ten years ago M.T.H. Electric Trains needed to make a decision as to whether it should include a rechargeable battery or no battery at all in its Proto-Sound equipped locomotives. The decision to require a battery in the first place was easily justified because when so equipped, the locomotive performs much more realistically and consistently. By designing in a recharging circuit into the Proto-Sound electronic board, the inclusion of a rechargeable NiCad battery inside the locomotive would allow the consumer to literally take the locomotive from its package and begin running immediately. No disassembly, purchase or installation of a battery was required of the M.T.H. consumer. More importantly, we believe the NiCad battery adds a minimal cost to the product with a major benefit. The inclusion of the recharging circuit does make the Proto-Sound board more expensive to manufacture, which may be why other manufacturers have elected not to include it in their own designs. But here again MTH believes the recharging circuit provides a major benefit by minimizing the need to replace the battery only once every 2 - 3 years. Since the introduction of Proto-Sound in 1993, much has changed about the system including a vastly improved recharging circuit found inside Proto-Sound 2.0 equipped locomotives. What hasn't changed is M.T.H.'s commitment to include rechargeable NiCad batteries inside each and every one of its Proto-Sound equipped locomotives. It should be stressed, however, that despite the inclusion of a recharging circuit inside every Proto-Sound and Proto-Sound 2.0 equipped locomotive, the NiCad battery will eventually cease to hold a charge and need replacement - no different than the battery inside the family automobile. In recent years, M.T.H. has been questioned about the choice of choosing NiCad batteries over other rechargeable battery designs such as NiMH. While it is true that NiMH batteries have more storage capacity than NiCad batteries, they may be as much as twice the cost. Furthermore, there are certain features of NiCad batteries that, we believe, make NiCad the better choice. For example: NiMH batteries self discharge faster than NiCads. This means the NiMh batteries will need to be replaced more often over long periods of non-use. The NiCad battery self discharge rate is 10% less than the comparable NiMH battery. This has a significant impact on the performance of locomotives right out of the box. For example, after 10 months of non-use, the NiCad battery has 3-4 times the stored charge (in "mAh") compared to a NiMH battery under the same condition. This means MTH locomotives equipped with the NiCad battery will most likely have a charge to operate properly the first time out of the box. NiCad batteries are rated at 500 to 5000 charge/discharge cycles compared to 250 to 2000 charge/discharge cycles for the NiMH battery. This means you will need to replace NiMH batteries more often if you regularly operate your locomotives. The NiCad battery has more than enough storage capacity to operate MTH locomotives properly. The NiMH battery costs more than the NiCad. Since the release of Proto-Sound equipped engines beginning in 1993, M.T.H. has received locomotives back for service that had nothing wrong with them other than a dead battery. NiCad and NiMH batteries don't last forever. Battery manufacturers tell us both have the same life expectancy of 2 - 3 years under normal operating conditions. In some cases they may last up to five years in others, only one year. Regular use of a Proto-Sound equipped locomotive will recharge the battery to its full charge condition. Infrequent use may contribute to some operating problems resulting from a discharged battery. Consequently, M.T.H. recommends that user's regularly run their locomotives or recharge the battery prior to use if the engine has not been operated for an extended amount of time (two months or longer). So, should you choose a battery based on your operating habits? In short, yes. The following should be used as a guide for battery choice. If you operate your trains infrequently (once a month or less frequently), stick with the NiCad battery that came with your engine. Because the battery holds a charge longer during non-use, the NiCad is the way to go. If you operate your trains frequently (at least once every two weeks) for short periods of time with multiple shutdowns and start-ups and can afford the higher cost of the battery, pick the NiMH for its higher capacity. One last comment about a recent article on batteries in Classic Toy Trains. CTT recommends replacing the original worn out MTH NiCad batteries. The article also suggests the reader consider using a NiMH battery. MTH agrees with this completely. However, many readers may miss 2 key points of the article. "Batteries deteriorate with age until they can no longer hold a charge or reach its full voltage capacity, no matter how long you charge it. At that point the battery must be replaced". "If the battery is bad, obtain a new NiCad from MTH or replace the NiCad with a 8.4V 150 mAh Nickel-Metal Hydrite (NiMH) rechargeable battery." Bottom line, there is no need to replace the battery until it no longer holds enough charge to operate your train properly. When it's time to replace the battery, choose the battery type based on your operating habits. Then go to your layout and enjoy the benefits (consistent realistic operation) a good battery provides in your MTH locomotive.