# airwire battery question



## todd55whit (Jan 2, 2008)

Anyone use a single 12 volt battery pack to supply their Airwire decoder? Book says 9-18 volt on low voltage side. I am trying to fit a battery in a short hood and 12 volt seems to fit perfect. The question is will it work???????


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## terry_n_85318 (Jan 3, 2008)

Yes.


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## todd55whit (Jan 2, 2008)

will I get a reasonable speed with the 12 volt pack?


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## Greg Elmassian (Jan 3, 2008)

What locomotive, and what scale speed do you want? 

My first answer would be if you want to go over 25 smph, you need more voltage. 

Regards, Greg


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## todd55whit (Jan 2, 2008)

Hi Greg, 
RS3. Sounds like I need to go to 14.4(nimh) or 14.8 (lion) I want to get the battery in the short hood and the p5,speaker/airwire in the long hood. 12 volt maybe to slow.


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## Greg Elmassian (Jan 3, 2008)

Todd, your RS-3 in switching would go slow. As a road diesel, I'm pretty sure 12v will be too low, the 14.4v option sounds better here, I agree. 

Regards, Greg


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## Bill Swindell (Jan 2, 2008)

I have an SD-45 with 14.4V and I think it is slow. I am going to up it to 18V. On USA, LGB & Bachmann, 14.4 works very well.


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## Rod Fearnley (Jan 2, 2008)

I have 12vlt Gel Cell in my S-4, it seems to be running at about scale speed for the size of my layout and the job it does. 
Rod


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## Paul Burch (Jan 2, 2008)

14.4v would be a better choice. The long low hood on the RS3's does present a little challenge for a battery fit. Here is an easy solution that works well.
http://www.batteryspace.com/nimhbat...obots.aspx

Two of these batteries strapped together and rewired in series fit easily in the long hood. At full charge they will be over 16 volts. This listing is only an example, there are several others listed with various prices and mah ratings ,but this one at 4200 mah will provide a good long run time at a reasonable price.


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## Del Tapparo (Jan 4, 2008)

My choice of late is Lithium-Ion. Here is a 14.8V 4800 mah battery for about $13 more that only takes up half the space. The 2 NiCads: 22 cubic inches, the Lithium-Ion: 11 cubic inches.
All-Battery.com Lithium Ion


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## Stan Cedarleaf (Jan 2, 2008)

Hi Todd, I use the 14.8 Li-ion that Del posted. Id get the 1.5 amp charger for it.


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## Greg Elmassian (Jan 3, 2008)

Hmm... 1.5 amp charger for 4.8 amp hours? How long to a full charge? Would guess you would have 2-2.5 amp charger. 

(of course slower charging usually means longer battery life) 

Regards, Greg


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## Del Tapparo (Jan 4, 2008)

Greg = 4.8A / 1.5 AH = 3.2 hours, if fully discharged. Since this charger has no metering on it, just a red LED when charging and Green LED when charged, I can't give you a measured response. 

Here's how I operate my battery powered trains -

I run them until I'm tired of it, which is always before the battery discharges, unless I'm doing an all day open house. I usually run for 2-3 hours though. All of my trailing cars or tenders have charging jacks. After the run, I bring the tender or or trailing car into the garage where my charging station is. Plug in the charger. This is usually just before supper time. Then I check on it a few times during the evening, and it is usually done well before bedtime. So I'd say it usually takes mine about 2-3 hours at most. Next time I want to run, I return the charged trailing car or tender to the train shed and decide what I want to run. Everything in the shed is always charged and ready to go. (Note: I've even had a system sit out there all Winter long, and still be ready to run in the Spring (NiMh). Not a full charge left, but runnable. And yes, sitting out all Winter is probably not doing the battery any good.)


I always hear guys saying they don't have time to charge batteries before running their trains. Neither do I. That's why you do it AFTER you run trains. Stan swaps his out. But it's the same difference, just charge after use. 


By the way, I charge my NiMhs at C/10 (10 hours for a full charge), so the Lithium-Ion seems fast to me. It doesn't really matter how long it takes. I'm off doing other things.


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## Greg Elmassian (Jan 3, 2008)

Thanks Del, yes I agree many people complain that it takes too long to recharge batteries, so that's where my question arose. 

I normally keep charging down pretty low unless I have a very smart charger... those hit C for a while and then taper off, but they need to be smart and also watch the temp, like a Maha. 

Thanks, 

Greg


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## acmartina (Jan 6, 2008)

Todd, 

A 14.8 v Li-Ion pack (4-cell in 2x2 configuration) fits very nicely under the short hood of the RS-3. It provides more than enough power. I got mine from www.batteryspace.com but they are available elsewhere including www.cordlessrenovations.com (owner posts here sometimes). Mine is 2400mah, which is good for a couple hours run time. Top speed is more than necessary for my tastes anyway. 12v would probably suffice. 

I separated the short hood from the cab and removed the tabs on the side so I can remove the short hood easily to charge the battery. 

Steve


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## todd55whit (Jan 2, 2008)

Steve 
Thanks for info. I will probably leave the battery in the loco and charge through a charging jack. Thanks all for help.


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