Rail truck RCS

[CCSG]

I converted my Bachmann rail truck to battery and RC. I used a Rx65 receiver mounted under the seat in the cab. I shortened the coffin box and mounted it sideways for the battery. The battery is a Turnigy 2s Lipo (7.4v) 850 mAh. I origanally planned on using a 3s Lipo (11.1v) 1300 mAh battery but the one I ordered was two tight of a fit. I like the speed it provides. I'm hoping to have enough room for a Phoenix P8 in the coffin box and my plan is to mount a speaker on the bottom of the cab roof facing down.

[Loco Bill Canelos]

CCSG,

Nice work there,  I love the compactness of it.   As a battery proponent especially of Lithium Ion and LiPO I am definitely interested in your experience going forward.    Maaybe you can let us know how it goes with runtime at 850 mAh.   

The only concern I would have with installing the P8 is that it might need more than 7.4 volts to operate properly.  My p8's work OK with the 14.8v Lithium Ion batteries.   

Where are you buying your batteries?  I have never heard of the brand you mention. Did you maybe mean Tenergy?

Good luck going forward with your project and thanks for sharing.

Bill

[CCSG]

Bill,

Yes they are Tenergy li-po. I bought them from hobbyking, they're prices seem very competitive. I know their are concerns with li-pos but there price and size are very good. I also bought a Tenergy smart charger that is very adjustable so hopefully I won't have a problem. I figure these are very popular with RC hobbyists and explosions aren't making the daily headlines. Thanks for the heads up about the P8 voltage, I wasn't aware of that. I don't know when I'll have the money to add sound to my three locomotives as that will be a big investment; 3 sound boards, programming cable and windows software so I can run it on my Mac. How does the P8 behave differently on 14.8 volts than higher voltage?

Patrick

[Tony Walsham]

To the best of my knowledge Hobby King (HK) do not sell Tenergy batteries.  Patrick had it right the first time.  The HK brand is Turnigy.
The Phoenix P8 instructions do not list a minimum voltage in the tech specs on page # 14.  Only a maximum voltage.  30 volts.
The only reference to a minimum voltage is during initial checkout on page # 6 where it states "When the power rises above 9 volts you should hear the sound"

[CCSG]

Tony,

I was just browsing on HK's website and I was just about to post a correction to battery brand but you beat me to it. I was looking to see if they offered any 14.8 volt batteries that would fit in my space after Bill's comment. Last night I also read up on the P8 manual. There statement on page 6 makes me believe that 11.1 v should work. I have only bench tested this rail truck so far. Hoping to run on a friends railroad in a couple of days.

[Loco Bill Canelos]

I do not know what the minimum voltage really is for a P8, but I do know that I have had no problem at 11 volts.   I think Tony's comment about the bench test tells the tale.  I always do the bench test and it does seem to have to be around 9 volts to trigger the sound. That may be where my concern about 7.4 volts being to low came from in the first place. A quick call to to Phoenix would resolve it for sure. They are great with responses and a pleasure to deal with.  The P8 is a great board.  I have had problems with low voltage on older Big Sound 97 and 2K2 with the separate rechargable batteries but I cannot remember what the threshold voltage was for sure. 

As for the LIPO technology, I agree it is pretty mainstream among the rc aircraft guys.  It amazes me how small they are.  There was a fellow on one of the German Forums who posted pictures of a tiny little loky that he battery powered using a flexible LIPO battery and it was so thin he was able to conceal it by conforming it to the inside of the cab roof.  Yo could not even see it was there. The president of our local rc aircraft club told me no member has reported any fires, explosions and such using LIPO.  He did say that some members complained about reliability in that for unexplained reasons sometimes the LIPO batteries would no longer take a charge.  Nothing really new there as I have occasionally had that problem with the older cadmium batteries and Lithium Ion's as well.

Bill

[CCSG]

Bill,

Thanks for the reply and clarification. I had originally planned on using an 11.1 v battery for my rail truck but do to stated measurements on HK's website, I had to switch things around a little. I'll probably run with the 7.4 battery a while till I spring for Phoenix. Thanks for all the info you provide here and promoting Bacmann Large scale!