Battery conversions and DCC boards.

[CoggesRailway]

Ok this sounds counter intutive.
I have converted one of my digital little ex lgb starter sets already as it had a broken decoder. I have a DC track and battery set up but bought two of these back at the start. They run fine on DC.

I now am to convert the other to battery - DC is to be retained only for visitors as track cleaning is boring!

SO THE QUESTION. If I find the voltage that "tells" the loco chip to go at a nice speed and build a battery to match with a reversing switch and connect it to the track power circuit on the loco (removing pickups etc) Will I effectively still have a digital loco with all it's lights, delayed start etc but running off battery. Or will flicking the switch on suddenly make it go pop?

Also as the voltage drops on a run would it then trigger the loco to gracefully stop, whilst still retaining most of it's charge? Does this mean that it would have very short run times - or does a nimh battery stay constant and die suddenly as oppsed to a linear reduction in volts...

BTW thanks for all the help - one day I will help others when I have the knowledge!

Ian

 

[Gizzy]

A battery is pure DC and it will power your loco, without a decoder, or as is your case, with it. The DCC board looks for either a DC or a DCC input.

A DCC supply is one with computer communication protocol superimposed on it. Think FM radio for example. A battery isn't an 'intelligent' device that gives commands, it only gives voltage.

Thus yes you can build a battry to give a voltage to drive your loco, but the chip is acting in DC mode, so you may as well remove the DDC chip, sell it on, and run on battery without it....

 

[whatlep]

Ian - in answer to your questions:

1) Running DC through the decoder from a battery). Yes, doing it is OK electrically: it's what happens when you run on DC from the track or via one of Massoth's Goldcap capacitance devices. As you say, you'll get the benefits of the decoders circuitry including basic DC sounds too if the loco is sound-fitted. The only real disadvantage is that you are losing some battery life to power the decoder's circuitry, but that doesn't seem to be a major issue on modern decoders (e.g. Massoth XL) though it does seem to be an issue with an old LGB 55021 decoder on one of my Stainzes.

2) If used immediately after charging NiMH battery voltage drops from the initial peak but then maintains a plateau level of good charge until the battery capicity is almost exhausted at which point the voltage plummets. If stored unused, NiMH "classic" technology is reckoned by manufacturers to lose 30% of useful charge per month, though that depends on several factors including battery Amp-hour rating. The higher the rating, the greater the rate of self-discharge. "Low self discharge" (LSD) NiMH batteries have better characteristics in both respects than "classic" NiMH cells, but cost significantly more. If you use your batteries every day, the difference is unlikely to be relevant.

 

[CoggesRailway]

Many thanks Chaps. I think I am going to progress this route as a simple way of keeping the lights working for now. If it doesn't work well I will cut out the decoder and use 12v leds prewired from ebay. Hopefully after I have some planned schooling I will be able to achieve more of this stuff on my own!

 

[yb281]

Hopefully after I have some planned schooling I will be able to achieve more of this stuff on my own!

Don't worry about that Ian, I'm learning with you and so may others.

 

[Bram]

Hopefully after I have some planned schooling I will be able to achieve more of this stuff on my own!

Don't worry about that Ian, I'm learning with you and so may others.

Absolutely, one never stops learning, it's remembering what you have learnt, that's the trick:thinking::thinking:

 

[Doug]

Massoth are bringing out a board that converts its DCC decoders into radio cintrolled ones using the wireless navigator as the transmitter, so this will allow full DCC with batteries and R/C

 

[CoggesRailway]

Update - in the process of doing the job I connected something wrong and cooked it. However I have ended up with a working conversion with directional lights sans dcc board.

 

[Cliff George]

Massoth are bringing out a board that converts its DCC decoders into radio cintrolled ones using the wireless navigator as the transmitter, so this will allow full DCC with batteries and R/C

Yes that would be the DRC 300 which is not yet available. This will actually work with ANY DCC equiped loco's not just those fitted with Massoth decoders. It can only be used with Wireless Massoth Navigators because the RC bit and what it carries is proprietary to Massoth. It sounds like a good idea, I'm not sure it is quite best solution that could be produced because it is basically a command station on a chip, usually there will only be one command station in a DCC system, this now suggests that there could be many, bringing possible problems, like having to configue the same thing into multiple devices. Point control would only be possible with DRC 300s fitted to standalone point decoders. A better solution in my mind would be have the command station in the handheld device and only carry the command station to booster interface in the RC. NMRA should define a standard for a wireless command station to booster interface.

I will be trying a DCR 300 when it comes out. It seems to be just about the best solution out there available anytime soon with users who already have DCC equiped locos. It should not be too expensive for anyone who already has DCC locos and a Massoth Navigator.
http://www.shourtline.swl4.com/DRC_300_Basics_en_Functional_Overview.pdf