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Discussion Starter #1 (Edited)
It appears practically everything I need to know about the Sierra is in the user manual that Soundtraxx very kindly sent me.

I have however still one dilemma, which battery to choose: Stay with the 9v nimh battery allready installed very professionally by the previous loco owner on the Soundtraxx Sierra sound Sistem and modify the shuff start with programing to compensate for the high voltage . (The easy choice). To buy the Power Sonic PS-605 Battery Soundtrax recommends as a replacement (The safe choice). Or to install 5 x 1,2 volts nimh batteries hooked up to produce the required 6v. (The best choice?)
I remember reading that Soundtraxx do not recommend the use of nimh batteries on their products. I would like to know why. Contradictory to this Soundtraxx recommendation is the view expressed in the last part "Sierra Battery Issues" of this very interesting article http://www.trainweb.org/girr/tips/tips6/sierra_tips.html Here the author points out that the batteries Soundtraxx uses die completely if not used very often. A great inconvenience considering that trains are a hobby and most people do not or can not practice their hobby constantly. The author argues that nimh batteries apart from being very inexpensive recuperate easily from long periods of being without charge and that they work perfectly with the Sierra .
I would very much like you experts to comment on this.
Thank you again for your patience and advice.
 

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The author argues that nimh batteries apart from being very inexpensive recuperate easily from long periods of being without charge and that they work perfectly with the Sierra .
The PS battery recommended by Sierra is a lead-gel and dies of old age quite rapidly. Most people replace them.
NiMH batteries should work, but be aware that they are almost as bad as the lead-gel type. If you don't recharge them often and let them go dead, they stay dead. Ask me how I know. (Or ask me how many expensive NiMH batteries are sitting in the 'recycle' box.)

Soundtraxx's board recharges the attached battery from track power and uses it to keep the sound going when the track is dead. The charge system may not be set up for an NiMH battery, which may be why they don't recommend them? If you aren't charging from track power, I suspect any 6V battery will work.

Soundtraxx made a small power regulator board, which I have used to couple the loco battery, often 22V, to the Sierra card. I think I have a spare, and I think Star Hobby, in MD, might still have one or two in stock. Give them a call.
 

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NiMh batteries will work fine, some are inexpensive and a very viable answer IMO. That said as Pete noted the Sierra card is not designed to charge batteries per say, it employs a regulated voltage output to charge the battery, nothing is in play to limit or recognize when said battery is fully charged. Nor does it matter what technology the battery is, the Sierra card just continues to charge no matter what... I use inexpensive 6V NiMh radio control aircraft RX batteries in several engines equipped with Sierra Sound cards. I charge the batteries with a separate or remote AUTOMATIC or Smart battery charger, this also helps to cycle/maintain the batteries.

NiMH batteries need to be form charged or fully cycled; i.e, charged/discharged at least three times to realize their full capacity and voltage. Thereafter trickle charging is fine for nor more than 24 hour period in most cases. It really depends on the output of the charger and the battery capacity. Simply divide the charger output by hours/minutes to factor a typical recharge time interval. For example: 120mAh charger and a 600mAh RX battery is in hand.

120mA/1000=.12Amps output
600mAh/1000=.6Ah
.6Ah/.12A=5 hour charge time.

600mAh/120mAh=5 hour charge time.

Keep in mind the above is reflective of charging a completely expired battery, not a partially discharged battery. That said low output trickle chargers can be allowed to run wild for a maximum IMO of perhaps 24 hours, this allows cells to balance charge themselves without the detrimental heat associated with higher current/amperage charging. Prolonged trickle charging is NOT a good thing...

Another consideration is NO battery at all, some of us have employed SUPER CAPCACITORS in lieu of batteries. These charge up when the railhead is powered and act much like a battery thereafter. The good part is you never need to charge them.

Michael
 

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Discussion Starter #4 (Edited)
Thank you Michael and Pete for all the valuable information.

In the Sierra owners manual there are instructions for very simply mounting an optional charging jack for the purpose of charging the battery while the system is idle without needing to take apart the loco or the tender. This plugged to a simple wall socket timer and charger seems to me an easy solution for charging batteries adequately but not excessively when the system is idle. Would this be OK?

The super capacitor option sounds extremely interesting , could you please expand on this. How this works, pros and cons, where to buy one and how to install it.

With the formula for determining charging time one could calculate when a 9v battery has reached 6v of charge and never charge it over this point. This way I would not have to change my present setup. I suspect this is not such a good idea. Or is it?
 

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Discussion Starter #6
I like the idea of super capacitors Stan, please tell me the reference to order them and how you installed them on the sound board. Thank you.
 

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Please could you(Stan) post the super caps reference to order them?
 

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trainstrainstrians,

May we address you by your name?

Yes, the optional charge jack is needed IMO in any circumstance with batteries. A simple inexpensive wall transformer with a timer works great for many... No charge jack for the Super Cap option.

Michael
 

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Discussion Starter #10 (Edited)
I' m going to try the supercap option since not having ever to worry about charging batteries is a clear advantage besides no one has commented negatively about supercaps and installing them seems straightforward and simple .

I found the ebay link to the supercaps, three supercaps joined together.
I wonder if this single super cap also from ebay would work?
5.5V 4F Farad Ultracapacitor Supercapacitor vertical config backup .
Or the one on the photo from Amazon?

Most likely three 1.7v 10 Farad super caps are better than one 5.5v 4 Farad supercap? More Farads means greater storage capacity which possibly means longer running time before it stops working? I just looked up Farads, I'm guessing the rest. A knowledgeable explanation would be interesting.

Thanks for all help.
 

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When you place 3 super caps in series the storage is divided by 3 so 3 of the 10f units is 3.33F.
However one assumes the sound board only puts out 5.1 volts or less!!

It would be safer to use 2 of the 5.5 volt in series which is 11 volts at 2F or 6 of the 1.7 giving 10.2 volts at 1.66F.

On LGB sound units there are 3 wires for storage and I use a voltage regulator to limit the voltage to the super caps.
 

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Discussion Starter #12
Farad confused

My knowledge of electronics is the layman's knowledge so practically none. So I am really confused now. You are clearly knowledgeable on this subject. My confusion is: If more capacitors = less Farads what is the point of having more? Clearly the object of the 3 caps used by Toddalin was to reach 5.1 volts charging capacity which is near the 6 volts of the battery the Sierra comes with. So why is it better to have 10 volts and less Farads? I somehow in my ignorance imagined that more Farads meaning more storage capacity meant longer time of sound while sound card is not receiving power from the track, so I thought more Farads was good. The people at Soundtraxx told me that the reason my Sierra is shuffling while standing still is because it is receiving too much voltage from the 9v battery installed. So 10.2v or 11v would be even worse. Or alternatively according to you I could keep my 9v battery? I hope this gives you people who understand electronics an idea of the confusion I am now in.
 

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Trains 3X

Yes, 9 volts into the Sierra is too much and can cause problems.... The Sierra boards were designed for 6 volt input to the board to work properly. The small 6 volt gel cell batteries originally supplied with the boards are a bit hard to find and can be expensive.

The Super Caps have been the answer for me for applications where I've had limited space to work with...

Many of the older installations have been done with all the sound and R/C stuff in a tender or "Battery Car". In those cases, I've used this 6 volt battery very effectively and have one that has been in operation for 6 years...
http://www.allelectronics.com/make-a-store/item/gc-612/6-volt-1.2-ah-battery/1.html

It may seem a bit overkill, but they work very, very well and are only $8

In a Bachmann Big Hauler Box Car used for the battery car.. Negative is connected to pin #2 and positive to Pin 4 through the DPDT on/off toggle switch. The Bachmann cars have been used because the roofs are very easily removed to change batteries..

 

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OK, I'm back.

You want to use three 2.7 volt (2.85 volt peak) supercaps wired in series. Anything less than this is a mistake and a potential hazard because the Sierra charges at (IIRC) about 8 volts. Caps in the 6 to 10 Farad range have proven to work successfully. 6 Farads will provide about 90 seconds time and 10 should be about 150 seconds after power is removed from the rails depending on the volume and other features (e.g., lighting) drawing off the caps. The LEDs will remain on a bit after the sound conks out.

Each cap is about the diameter of a AAA battery and about 2/3 as long and ~$2 (in packs of 10) on the bay and you will never need to worry about leaving the sound on or charging a battery again. You don't even need the charging jack (or wall wart) and will never use it again.
 

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Train3x when dealing with capacitors in series, the farads divide by the number of units in series.
These units only add if wired in parallel, but now you do not have the higher voltage rating needed.

Resistors are the opposite, they add in series and divide in parallel.
 

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Hi Guys... Here's the link to the items on ebay now..


http://www.ebay.com/itm/6-8F-2-7V-f...LH_DefaultDomain_0&hash=item3ced4dcc22http://

Or search for this item on ebay

6.8F 2.7V farad Supercap Ultracapacitor x 10 pcs quick charge discharge slim

I'll see if I can get an image for you later tonight... I'm out running trains at a Christmas show today..

Sorry for the delay, see this post for the reason... Had a heart attack....

http://forums.mylargescale.com/16-t...adbed/23598-1-scale-really-70.html#post680458
 

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Discussion Starter #18 (Edited)
Thanks Toddalin, Dan and Stan.
Will do. Not to ever have to charge batteries must be a blessing. Wish cellphones could work with supercaps.
Since you obviously know what you're talking about I need not fear that the higher than 6 volts of the supercaps will mess up the various settings of the Sierra. They are pretty messed up right now. I Don't really know for what reason. Perhaps they were messed up when I bought the loco second hand. Perhaps like Soundtraxx suggest the 9v NON RECHARGEABLE battery I have in it is messing things up. The exhaust sound sounds randomly sometimes when the loco is still sometimes when it is moving. The dynamo sound is always on very loud. The bell I have not heard yet. The rest works properly I believe.
Fortunately I now have the Owners Manual and am studying the programming procedure with the + & - volume buttons. If you have advice on programing in relation to supercaps please tell me. However I am confident that with the help I have been given in this forum and the Owners Manual I will manage. So thank you and thank you all. I will post results.
 

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The goal is to provide a capacitor(s) that are able to absorb the charging circuits operating VOLTAGE. Anything less is undesirable, there’s nothing wrong with a capacitor bank rated for a higher voltage as the caps in play will only charge to the sum of the input voltage realized from the Sierra cards charging output (approx. 8.0VDC MAX).

In this example it’s known that the Sierra card outputs about 8.0V. So were looking for a capacitor bank with some headroom (<8.0V).

Calculations for supercapacitors wired in SERIES are noted below.

Noted, from eBay links:

2.7V/10F
3x2.7v=8.1V
3.33F OR 1/10+1/10+1/10=.3, 1/.3=3.33F

2.7V/6.8F
3x2.7v=8.1V
2.27F OR 1/10+1/10+1/10=.44, 1/.44=2.27F

Amazon link:
5.5V/0.33F
2x5.5=11.0V
6.06F OR 1/.33+1/.33=6.06F

Supercaps are confined to 2.5-2.7V offerings. Farad ratings vary.

It’s plausible to utilize supercapitors of varying Voltage/Farad specifications in series/parallel configurations if desired.

Michael
 

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Discussion Starter #20
You've just cleared my last doubt, I now understand the logic.
Out of curiosity and not very important I hope, this new knowledge makes me wonder if the fact that I have a non rechargeable battery in the place of the original, no charge from the card is received by the battery which could be the cause of malfunction?
 
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