# Replacing Sierra gel cell with NiMH battery



## tj-lee (Jan 2, 2008)

Like many others I have an engine (Bachmann Shay) equipped with a Sierra sound system and like many of you the 6-volt gel cell lead-acid battery kept dying.


I've been told that the reason is because I don't run my trains everyday and often leave them on the shelf long enough for the gel cell battery to go dead/flat. On George Schreyer's site I found a lot of great information on this issue and how George solved the problem by replacing the gel cell battery with a NiMH battery. George, being handy, made up a battery pack from parts. Me, not being handy, discussed the issue with Roy (of Roy's Trains my LHS) and Roy found a supply of ready to plug in 6-volt NiMH battery packs that should be a straight replacement for the dead gel cell.


So I mounted my Shay in my upside down engine holder and was ready to do surgery.











My Sierra sound system was installed by Dave Goodson and on Dave’s installations the gel cell is mounted on the undercarriage of the Bachmann Shay. Snicker-snack with the wire cutters and the old, dead, gel cell was removed to make room for the new NiMH battery pack.










The NiMH battery pack that Roy had came with a Tamiya female quick connect attached to the plus and minus leads. I stopped by Radio Shack and found they had the corresponding male connector (actually I had to buy a set of leads, male and female) in their RC 9.6V Battery Pack Connector Repair Kit (Model: 23-445, Catalog #: 23-445). 

As George pointed out in his white paper the form factor between the gel cell and the appropriate number of NiMH cells is nearly identical. I found that on my (2) truck Bachmann Shay that the NiMH cell pack fit perfectly in in the frame carriage where the gel cell was located.










As you can see above, the NiMH cells are packaged in a bright lime green wrapper and the quick disconnect is huge and made of white plastic. Now it’s all underneath the Shay and therefore should not be visible but most of my layout is raised off the ground, so I touched up all the exposed bits with some black acrylic hobby paint.











Sound system is now back online and working great! I’ve not yet run the battery down and tried to recharge via the recharging jack but I don’t anticipate any problems with that.

Some more details and few more pictures in the article here (along with links to George Schreyer's page, and other links):

http://tjstrains.com/1019/replace-g...h-battery/

Best,
TJ


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## Greg Elmassian (Jan 3, 2008)

Nice job TJ... you are expecting these to go flat too if the loco is not used in a while right? The reason for changing in George's article is he believes that a fully discharged gel cell will die, but a fully discharged Nickel Metal Hydride battery will not be damaged from complete discharge. 

I'm not of the same opinion, but perhaps they last longer, or are damaged as much. 

One suggestion: charge them whenever you can, instead of letting them discharge completely. (using the on-board charger, it seems that it does not shut off at full charge, it's just a simple constant current, low rate charger) 

Regards, Greg


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## David Buckingham (Jan 2, 2008)

Hi TJ 
Nice Job but with Sierra sound you MUST have an on off switch as it will drain the battery quickly unlike the phoenix systems. 

Having said that even with a switch on short runs it will not have time to charge. 

If your loco has an on off switch in the boiler that will switch off the motor but leave the sound on you can charge it that way. 

My Sierra equiped locos now all have Nimh batteries on of swiitches and a charging circuit from plug in chargers 

I also run trains in sequence and I have rather a lot of them it takes about 1 1/2 hours before it is run again. 

Dave


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## Dan Pierce (Jan 2, 2008)

Hmmm, possibly another good case for super caps. Need to know the max voltage the recharge circuit supplies to determine the amount of super caps to stack in series.


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## Trains (Jan 2, 2008)

I have a B-mann shay, sits on the shelf a lot. I found if you put a off on switch in line with the battery it will stay charged
longer.

Don


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## Bob Pero (Jan 13, 2008)

I have 12 locomotives with Sierra sound systems. I have two Sierra charging units that get rotated through the whole roster every month. I keep a maintenance book with each locomotive listed. Notes are added as to when it was last on the charger, when lubrication was checked etc. Makes a big difference when I send them out to run on the layout.


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## tj-lee (Jan 2, 2008)

Greg,

> I'm not of the same opinion, but perhaps they last longer

Well, I hold both yours and George's opinion in the highest regard, so I'll not take sides given my lack of book learning and first hand knowledge in this area.

But if nothing else I can now very easily swap out the NiMH battery pack and as that pack is cheaper than what I was paying for the gel cell so it's an improvement in general. And the project did prompt me to build my upside down engine holder which works really great.


OTOH, not sure what to do about the shelf time my locos get due to the circumstances of my life. They can sit for months, which is why I really liked George's contention that the NiMH would tolerate going flat and with a recharge come back to life.

Best,TJ


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## tj-lee (Jan 2, 2008)

David, Don,


> Nice Job but with Sierra sound you MUST have an on off switch as it will drain the battery quickly unlike the phoenix systems. 

>I found if you put a off on switch in line with the battery it will stay charged longer. 

I have two switches, installed by Dave Goodman when he installed the sound system in the Shay. Once toggles the volume up and down, the other is on/off. Is that what you are referring to?

Best,
TJ


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## tj-lee (Jan 2, 2008)

Bob, 

> I have two Sierra charging units that get rotated through the whole roster every month. 

Maybe I need to employ the same type of discipline to keep my batteries charged. 

Of course, would be easier if I could just chuck work and surly teenagers and just run trains every day. Sigh. 

Best, 
TJ


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## tj-lee (Jan 2, 2008)

Dan,

> Hmmm, possibly another good case for super caps.

I appreciate the reply and the tip, but I am clueless as to what a "super cap" is or how I would employ it.

Best,
TJ


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## Greg Elmassian (Jan 3, 2008)

In terms of not losing a charge when sitting idle, the top of the heap is lithium ion. 

Next down is probably nicad and nimih 

The gel cells don't seem to hold quite as long, but are close. 

But ALL batteries will eventually self-discharge, and my experience is that there's not a lot of difference between gel and nicad and nimih... 

Now the point that George brought out was that his experience was that given the battery has gone completely flat, nimih will not be damaged from this, but gel cells will. 

He might be right on this to a point... BUT, any rechargeable cell is damaged to a degree going flat and this is where my "disagreement" lies. 

If I was in the situation you are in, I would do what Bob recommended (and it is what I do to my stable of rechargeable batteries, I have about 50)... keep them charged in rotation. 

If that was too onerous, then I would go the supercaps, because they should handle going flat better than batteries... 

I keep my batteries organized near the chargers, and when I go into the garage, disconnect one, and put another in it's place, I have the batteries organized so it's easy to "rotate" the charging. 

Perhaps you could do this with your locos. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Greg. 
Were you aware of the hybrid Alkaline- NiMh batteries developed specifically for digital cameras. 
One brand is ENELOOP made by Sanyo. 
They are sold fully charged and are guaranteed to hold 85% charge for 12 months. 
I have found those claims to be true having used the cells for 5-6 years now.


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## Greg Elmassian (Jan 3, 2008)

Yes, they do have quite good shelf life. I bought a number of them based on your recommendation, in fact! 

Good point Tony. 

Greg


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## David Buckingham (Jan 2, 2008)

Hi 
The cells Tony is talking about are easy to get nowdays and come fully charged they loose about 20 percent per Year not per month like normal ones. 

Your local model shop will I expect have them available if not one of the mail order places( Ican tell you where to get them this side of the pond) 

The Switch that Must be turned of is for the whole sound system 

Note to charge the battery leave the the sound on turn the speaker off and leave the track power on for a few hours. 

Dave


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## Trains (Jan 2, 2008)

Yes Sir, that's the two. Mine stays charged about a year.


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## Dan Pierce (Jan 2, 2008)

Super caps are the storage module that LGB uses. They are available as an option for the LGB 6500x series sound modules and can be added to some LGB sound units/locos. All LGB F7B units have these on the sound board stock from the factory. 

I spent less than $30 for parts and made my own for my LGB sound units and I believe these can be used in place of batteries for any sound unit.


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## Greg Elmassian (Jan 3, 2008)

It really depends on the current draw of the unit. For the most run time from the same volume, I believe batteries still win. 

But, you might get acceptable run time from super caps, depends on your particular running style, voltage, etc. 

Greg


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