The battery is 14.8v.
800 to 1000 ohms will be sufficient. That’s what I use in all my installations with 14.8 volt batteries. I haven’t a clue whether the resistors are 1/4 watt or 1/2 watt; they were purchased in bulk eons ago. They’re the same physical size as resistors I’ve bought from Radio Shack marked 1/4 watt. They work; I don’t argue with success. If you’re buying new and the 1/2 watt is available, then go with that for the added headroom. They’re usually just a few pennies more.
In terms of the fuse, I haven’t played much with the polyfuses, though I probably should. I use garden-variety fast-blow 5-amp glass fuses from RS between the power switch and the electronics.
The catch with the Li-Ion batteries is that the batteries themselves are “protected.” That is to say, the PC board that controls the battery pack will shut itself down in the event of a short, thus protecting the battery. Unfortunately, my experience has shown that (a) it takes only a momentary short to cause this to happen, and (b) the board is toast as a result. Easy enough to replace, but more expensive than a fuse by a fair margin. The question I’ve not seen an answer for is whether a fuse (or polyfuse) would blow before the board “takes one for the team.” All the boards I’ve blown were the result of me being careless when installing or handling the battery outside of the installation.
Later,
K
Kevin Strong said:
…The question I’ve not seen an answer for is whether a fuse (or polyfuse) would blow before the board “takes one for the team.” All the boards I’ve blown were the result of me being careless when installing or handling the battery outside of the installation.
Later,
K
Poly fuses are very slow. I’ve stopped using them on my control boards and depend on the 5-amp glass fuse in my Battery Conversion Modules.
The first thing you need to do with any battery pack is install a quick disconnect connector for safe handling, regardless of your charging methods. Then you only have to be careful one time!
As Del says, Polyswitches are quite slow until they get up near their tripping temperature, then they are quite fast.
They are OK for basic protection of system wiring but not fast enough for protecting IC’s etc.
One way of making them “blow” faster is to put lower rated ones in parallel rather than having one high rated Polyswitch. That is because they do vary a little bit and once one has tripped the other(s) will trip instantly.
Fast blow glass fuses are much faster, but a pain to replace if buried inside a loco.
I tried that calculator, entering 14.8 as the source voltage, 3 as the forward voltage, and 100ma forward current. It said I need a resistor that is 120 ohm, 1.2 watts. Since this is quite a bit different from what Kevin is using, I’m wondering if I’m using the calculator correctly or if there is some other error?
Ray I thank your ma is wrong generally it is 15 ma. and that would give you 820ohm 1/2 watt.
Here are the specs for the LEDs I’m using:
http://www.theledlight.com/pdf/SS5WMSECC-A3.0-3.2V30-40degWarm6000MCD.pdf
I used the “peak” current, but probably should have used the “continuous” current, which is 30ma. That gives me a result of 420ohm, 1 watt.
Is this correct?
Yup. Use the “continuous” current value.
LEDs are pretty easy to understand. You just need to know a little about electricity. See http://barefootelectronics.com/led001.aspx
For decades, I’ve routinely run LEDs with pulses way above their continuous current rating, but a duty cycle so the average current was within the rating, but lately, I’ve seen white ones fail doing that.
Woohoo! I got everything hooked up and tried it out, and it works! Didn’t have time to do much with it yet, since it was getting dark by the time I finished.
Quick question: When I power it off using the Revo controller, it’s OFF, right? I don’t have to unplug the battery from the loco or anything?
There should be an on/off switch between the electronics and the battery, otherwise there will be some power drain through the electronics. Is there a small LED on the REVO to let you know that there is power to it? That will drain most batteries in a day or two.
Del Tapparo at G Scale Graphics makes a good one with and without a charging jack. Tony Walsham at RCS makes a similar module.
Well, I decided that splicing in a power switch at this point would be too much trouble. I’ve got it set up so I just have to lift off the oil bunker for access to the battery, and can just as easily unplug it.
I’m late to this thread… Is Ray of all people thinking twice about DCC ???
VBG
When you stop your train with the revo, the revo itself is still on. You need to disconnect your battery, like with a switch.
Glad to see you’ve been delivered from wires to the track.
John Le Forestier said:
I’m late to this thread… Is Ray of all people thinking twice about DCC ???
VBG
Not DCC, just battery power and Aristocraft’s Revolution control system. I already had the Revo installed in my narrow gauge RS-3, but running off track power. I never even got around to putting the Revo receiver in the Annie until now – was always too intimidated by the thought of dismantling it. Turns it to be simpler than I thought.
I’m really happy that it all worked out for you, Ray. I know you will enjoy the simplicity of the battery power and the Revolution. I wish you all the best with it.
Ed
Just woke up from a long winter’s nap and heard someone (Ray Dunakin, actually) mention battery power advice. Because I’ve suddenly become fascinated with operations (thanks a lot, Chandler), I too would like some advice on installing batteries with an Aristo system. So, with apologies to Ray, I’m hijacking his thread.
The backstory: I have two Aristo Train Engineers (prolly the older version since they are several years old), running on track power. They are mounted in the tenders of my two Bug Maulers (with Barry drives), along with Phoenix sound systems.
Now then, my questions: why can’t I just disconnect the track power leads, attach the leads from a battery, maybe throw in an on-off switch and a fuse (all in line, I’m guessing) and let 'er rip? Or burn up, maybe. It don’t gotta be fancy, just runable. I guess I could/should mount the battery in the boiler, since the tender is full. A few years ago a good friend who unfortunately died of the big C, started to wire up a system for me with a charging jack and all, using some Radio Shack batteries. I never could figure out how it was supposed to work and never finished the job. At this point I’d be content just to see my locos run, figuring that if the batteries need charging, I’ll just yank them out and recharge them. After all, I am a cave man!
So, what kind of batteries do I need? And where do I buy them and their chargers?
Of course, if you guys want my setup the work properly, feel free to throw in some advice.
BTW, found these at http://www.batteryspace.com/14.8V-500mAh-1800mAh-Battery-Modules.aspx
Why can’t I just hook 'em up and go? If so, which one should I get?
Another source for batteries and chargers you may want to consider: https://remotecontrolsystems.com/
I’ve done all the Bat/RC installations in my own locos and it’s not all that difficult. Fortunately I also had a wiring diagram to go by which included adding a sound card. So what you describe should work, although I’m not all that familiar with the Aristo system.
Battery choice is also what you’d be comfortable using. I have a combination of NiMH and LiOn batteries. Both require a smart charger . Personally I would go with the biggest mAh battery you can fit in the loco. The more mAh’s the longer it will run. I have a 5600 mAh battery in my K-27 and I’ve ran that thing all day long and never had the battery die on me. It’s also a big loco with a lot of room inside it for all that stuff.
And there are also a lot of people on here with more expertise than I have that will keep you straight…
Joe - You can get everything in the tender of your Bachmann 4-6-0s; R/C, Battery, sound, speaker. Please see the manuals on my website for general instructions on battery power conversion and a list of everything you need to do it. http://www.GScaleGraphics.net
Roger that, Del. In fact, after I posted, I got to thinking and realized that the battery should fit in the tender jes fine.
I guess, once I pull the plug on track power (i.e. turn off the juice, disconnect the wiries) it won’t matter if the wheel contacts are still in place, 'cause there’ll be nothing coming from them, right? So no short circuit worries when the loco derails, which it likes to do when traversing turnouts (I keep a supply of 10-amp fuses on hand to reset the Train Engineer’s X-mitter).
Err, what about the chuff drum? I guess I keep the wire running from the contact drum in the loco, to the tender. On my first install, I tried magnets glued to the tender axle, but felt the chuff rate was too fast. It would be nice to make the sound more random, like in a real loco. As it is, it’s too measured and if ya run your loco really fast, which isn’t prototypical, but amuses visitors, the sound all mushes together and sounds like white noise from a bad loudspeaker.