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Discussion Starter #1
I had a lot of battery trouble at Marty's I have been using Chicago Electric Cordless drill batteries for years with great sucess. I had a few Fail this year due to age.

I bought 4 new ones for Marty's. I had trouble making two laps around Marty's layout before they were dead.

It is time to re think my batteries.

I am now looking at what Bubba is using. Milwalkee cordless drill batteries.

To add to all my frustrations I connected a battery to my Air Wire Reciever reverse polarity. I toasted my Air Wire Reciever.

Someone at Marty's had a big hunker of a Diode ineries with thier Positive Lead.

Does anyone know what type to put in seires with my positive lead to prevent damage due to wrong polairity?
 

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and the downside is it will drop about 1 volt, which means if you have a 14.4V battery pack, it is now only good for 13.4V. You are better off just getting the wires straight in the first place.

As for the batteries, maybe your charger isn't up to par?
 

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Also John, what engine are you trying to run? A properly sized battery will save a lot of your problems.
 

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Instead of placing a diode in series thus lowering the voltage, place the diode across the receiver leads so that if backwards you create a short. This will blow the fuse (you do have a fuse installed do you not?) which costs much less than a controller/receiver.
 

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Dan, that's a very good idea.

By the way, running NiMH, NiCad and Li-ion batteries without a fuse can lead to FIRE and melted pieces. !
 

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Posted By Del Tapparo on 09/30/2008 6:58 PM
and the downside is it will drop about 1 volt, which means if you have a 14.4V battery pack, it is now only good for 13.4V. You are better off just getting the wires straight in the first place.

As for the batteries, maybe your charger isn't up to par?



Those HarborFreight / ChicagoElectric batteries are only rated at 1.4 amp hours at best. I think if I was to go the power tool battery route, I'd go with lithium. I really like the lithium packs I have with Makita drill and impact driver. They hold a charge much better in storage than any Nicad or NiMH packs. -Brian
 

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John,
Have you thought about gettting away from the power tool batteries? On models that I have done for others I just go a simple route with something like in the following link. Buy two,strap them together,wire in series and you have a simple high mah pack. Granted,14.4v but for me that is enough. Look at the physical size and mah rating on these compared to the tool batteries. If you use the Tamiya connectors it will also eliminate the polarity issue as they can only be connected one way.
http://www.all-battery.com/72vrccarbatterypacks.aspx

http://www.all-battery.com/connectors.aspx
 

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Jerry,
A couple things. I don't pesonally use these packs,I build my own 4200mah packs from individual cells. With two of these wired togeter you actually have a 14.4 volt pack and would thus need a charger for 14.4volts. I have a LGB Mikado here that I converted to Airwire and P5 sound for a friend. It is setup for one of these batteries. I'm guessing about 2-3 hours of run time with an average train. Run time is just too variable to come up with a good run time answer. My point with these batteries is that they are an easy compact solution with a good mah rating.
 

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Super Modulator
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You can use a Schotky diode in series with the input. They have a voltage drop about half or less than a normal diode. Easy and quick.

Regards, Greg
 

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Posted By John J on 09/30/2008 5:23 PM

Someone at Marty's had a big hunker of a Diode ineries with thier Positive Lead.

Does anyone know what type to put in seires with my positive lead to prevent damage due to wrong polairity?



JJ...... I have a bunch at home. I'll mail you a couple when I get home....
 

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Posted By Jerry Barnes on 10/01/2008 7:01 PM
WOW Paul, those are some darn good prices for such large mah ones, LOTS cheaper than Radio Shack. Will the 7.2 chargers I have(for smaller packs) work okay with those? How long a runs do you get with the 3800's? Jerry



Jerry,

I have used a couple of their 8.4v 3.8Ah packs to make 16.8v packs. I get 3-4 hours of run time with my Aristo E-8 pulling a head end box car/battery-TE car and 3 smoothside cars.


-Brian
 

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Discussion Starter #15
So is it safe to assume that if you put 3 of these packs in series you cold run on 21.6 volts for a long pieriod of time?

This looks like I could make my dummy SD 45 a battery car.
 

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John,
At full charge a NIMH 14.4 pack will read about 16 volts,so three 7.2v packs in series would be about 24v at full charge. I never have put three in series but see no reason why you couldn't. If you are going to try these I'd go for the 4200mah. Before I bought them,I would make sure there is a charger available that will charge the 21.6v NIMH pack.
 

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Hey guys take a look at these: http://www.all-battery.com/4tenergypcbprotectedli-ion1865037v2200mahrechargeablebatteries.aspx. These 2200 Mah Li-ion batteries are what I use to make a 14.4volt battery pack. Talk about cheap at 28.99 plus a buck for a connector you get a heckuva great batterypack and unlike the NIMH you only need one pack instead of two. In another thread I reported my results using a Connie. I t ran for 5& 1/2 hours continuoi=usly pulling about eleven cars on level track. They are so compact I get everything into the tender. They are extremely light compared to heavy drill batteries. The batteries h built in PCB protection circuits and I have had no problems, when fully charged they test out at 16.2 volts. I use Tamiya connectors and that eliminates the polarity problem because you can't connect them wrong. I have 6 Li-ion packs ade this way and no longer need a battery car for anything. I modify tenders so the coal load lifts off and exposes the batteries. It just takes seconds to switch out a battery. The Teneregy Universal smart charger is cheap as well. No problems charging either, the batteries remain cool while charging, and the charger gets slightly warm. No problems what so ever.
 

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At $16.99 each, I find these a little hard to beat. I wire 2 of them together for 19.2v and hide them in the tender of my Mallet.

Ooh. Forgot the link: All-battery.com



Alas, they won't fit in my bachmann tender.
 

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Master of Disaster
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John I can send you the link to All Electronics.


http://www.allelectronics.com/index.php


As for the size of the diode I can send it to you when get home...and the diagram that Stan Cedarleaf sent me waaay back when I first got into using the Airwire stuff...only I added EVERYTHING in the diagram that you may want to add to make installs easier for ANYONE to follow....diodes...... I purchased approx. 10-15 of them...always nice to have extras around.

Even though you might of fried the motor outs to the Airwire board..you can send the board in to Al at Airwire and iif it can be fixed it might only cost you $60-75 to get it repaired...alot less then the new board asking price.

I purchased a Airwire board from a guy in ther club that dropped out and sold his stuff..one board worked and the other did not...I sent it in and Al fixed it for $65 so I subtracted that from the $100 he wanted for it


And I must clarify that I use the batts Marty turned me onto 18 volt Milwaukee batts ...what I turned him onto was the triple bay Milwaukee charger...I have 2 one that only charges the NiCads and one that will charge the Nichol metal hydride AND the NiCads.


I bought the charger on Ebay the one that charges the Nicads only are approx $47-50....I paid $115 when they came out...the one that charges BOTH is still 1pprox $140-50..approx


Hopes this helps

Bubba
 
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