7.2v Battery Packs for Trains- any use?

robbieg96 · Post by **robbieg96** » Tue Jun 11, 2013 1:49 pm

Hello All,

Has anyone used a 7.2v nimh battery pack in a Loco? These are the classic RC car type battery packs that usually come with a Tamiya connector.

I am thinking of putting one in my Accucraft Baguley loco, as they are pretty cheap on Ebay- but is it worth it?

Thanks in advance!

-Rob

Big Al · Post by **Big Al** » Tue Jun 11, 2013 1:54 pm

Just a note of caution many cheap Chinese copies of these batteries about. they don't hold a charge for long and possible over heating problems so it mite be false economy :( A good place for batteries and radio control Items.
http://www.componentshop.co.uk/batterie ... ntrol.html

WVLR · Post by **WVLR** » Tue Jun 11, 2013 1:55 pm

I Have an 1800mah one that I was going to use in a loco
with a Viper speed controller but it's a heck of a size 130x45x25
it also took over 5 hours to charge using a fast smart charger.
So I've abandoned the idea for the time being.

vjoneslong5040 · Post by **vjoneslong5040** » Tue Jun 11, 2013 2:11 pm

I agree with Big Al, http://www.componentshop.co.uk/ is the place to go.

I've used their battery packs in 3 out of 4 of my rc steam engines, and spliced 3 of their 2600mah in series to give 14.4v for my Accucraft Baguley. I tend to charge it overnight on a smart charger, and it will run for hours. I've just ordered two 12v 2600mah packs for another battery electric to wire in parallel to give me even longer running.

LnBmad · Post by **LnBmad** » Tue Jun 11, 2013 3:10 pm

I will be fitting mini lipo batteries in my lyn.

A good set of mini Rc cells at 1500mah should set you back about £25 for 6 cells

Narrow Minded · Post by **Narrow Minded** » Tue Jun 11, 2013 4:14 pm

vjoneslong5040:84696 wrote:I've just ordered two 12v 2600mah packs for another battery electric to wire in parallel to give me even longer running.

Be cautious about wiring re-chargeables in parallel - I've done it in the past, but I know you're not supposed to

WVLR · Post by **WVLR** » Tue Jun 11, 2013 5:00 pm

I wouldn't advise wiring Nimh batteries in parallel, it's not good practice
as they CANNOT be charged in parallel.

Have a look at http://www.powerstream.com/NiMH.htm

I also would be VERY wary about using Lipo batteries in a loco, appart from the fire risk there not designed for this type of application.

LnBmad · Post by **LnBmad** » Tue Jun 11, 2013 5:12 pm

Having ran lipos when racing Rc cars I understand how they work. I will be using the lipos to power the loco. This they will be able to do perfectly fine. As for the fire risk I'm fitting them in metal cases in the tanks just in case.

WVLR · Post by **WVLR** » Tue Jun 11, 2013 5:15 pm

As for the fire risk I'm fitting them in metal cases in the tanks just in case

Make sure that they are well vented, I'll be sticking to Nimh.

LnBmad · Post by **LnBmad** » Tue Jun 11, 2013 5:36 pm

Tbf, just tested the lipos I was going to use (old Rc car) and 1 is now unbalanced and the other has a crack so I will be disposing of these tomorrow and will prob run 12 Nimh's instead. They are a lot easier as you have said

WVLR · Post by **WVLR** » Tue Jun 11, 2013 5:40 pm

Good Man

jay1976 · Post by **jay1976** » Tue Jun 11, 2013 5:57 pm

yes i am using a few in my locos.. I got 1 in a faller loco which runs nice and slow as the loco has a 12v motor and can run for 4 hours on a 6 year old 2800 battery.. also got a big big ruston with 2.4 radio control and can run for 6 hours roughly with a 3300 battery..
I cut the connector off and soldered the wires up and added a charging socket and on the charger added a new plug so trains can stop and be charged up in 30mins.. My batterys are all 6 years old possibly older and came out of radio control cars I used to have..newer batterys might make mine run for longer as well.. battery packs arent expensive now.

robbieg96 · Post by **robbieg96** » Tue Jun 11, 2013 8:21 pm

Thanks guys for the posts. Some great points there.

At the mo i am running 10 rechargable AA size batteries (Ni-MH from Maplin) in my Accy Baguley (and using a Timpdon SpeedCon+ manual controller). The system works great, I am just fed up of having to take the body off the loco each time to charge the batteries.

My electronic knowlege is pretty basic, but i managed to convert the loco myself.
If anyone could explain how to wire a re-charging point into the circuit then i would be really really greatful! I have been meaning to do it for a while now!

Thanks,
-Rob

jay1976 · Post by **jay1976** » Tue Jun 11, 2013 10:05 pm

I just run a wire from + and - just before the on-off switch to a socket(I used a socket from maplins and bought matching plug I have used several sockets for all my locos so i can use 1 charger for all of them)
make sure the polarity is the same on plug and socket before connecting your charger

WVLR · Post by **WVLR** » Tue Jun 11, 2013 10:25 pm

The standard seems to be the 2.1mm socket, Maplin
part No. JK09

Just to qualify that, 2.1mm is the centre pin diameter.

robbieg96 · Post by **robbieg96** » Wed Jun 12, 2013 2:18 pm

Thanks guys for your replies. That has really helped.

I have knocked up this diagram quickly (sorry its a bit poor!) using your advice and some other info from the net.
This is the circuit in my loco, and i have added in the charging circuit. Would this work if i was to install it like this?

Thanks

-Rob

LnBmad · Post by **LnBmad** » Wed Jun 12, 2013 2:55 pm

Yes that should work if your running manual control

WVLR · Post by **WVLR** » Wed Jun 12, 2013 3:02 pm

The diagram shows the switch wired incorrectly, the battery
should go to the middle (common contact) and the charging socket
to the outer.

the switch will then change between Charge (loco OFF) and
loco ON (charge OFF).

Also the diagram seems to show the reverse switch wired incorectly.

robbieg96 · Post by **robbieg96** » Wed Jun 12, 2013 3:44 pm

thanks guys for the pointers! Is this an improvement? If so, i will improve the drawing the hopefully it will be of use to others.

-Rob

WVLR · Post by **WVLR** » Wed Jun 12, 2013 3:46 pm

That's looking more like it Rob

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7.2v Battery Packs for Trains- any use?

7.2v Battery Packs for Trains- any use?

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