Battery powering a USAT diesel loco

[Ian Powell]

I have trawled through the forum for a similar article but to no avail.
Has anybody fitted a Cliff Barker R/C to a large USAT diesel? I have just purchased a new GP30. I already run a Bachmann Big Hauler with a CB unit and am well pleased with it. There is plenty of room for the unit plus batteries but it is the R/C unit that is giving me problems. I spoke to Cliff yesterday (he is on holiday at the moment) and he could not help unless I gave him more details on the powertrucks amperage.
He sells receivers 10-20 volts. I suggested that I may need the 16-28 volt unit.
Help appreciated.

 

[chris m01]

10 to 20 volts should be fine for a GP30. the maximum is 24 volts but mine goes plenty fast enough on 18 volts. My concern would be the amps. I'm not sure whether a Cliff Barker unit is designed for the load.

From what I can remember a GP30 will take about .5 to .6 of an amp per motor in normal running. I'm told it is considerably more at stall but I haven't seen this for myself. So thats around 1.2 amps pulling a lightish load on track which is close to level - say less than 1 in 50 incline. Obvioulsy the heavier the load or the greater the incline the larger the number of amps. I haven't measured the GP30 but the very similar GP7 draws quite a current for the lights - another half an amp or so. That means you will be running uncomfortably close to the wind with a 2 amp controller. Probably best to leave the smoke unit swithced off as this will drain the batteries very quickly and I think adds about another amp to the power consumption.
So the 10 to 20volt 2.8 amp continuous version might be ok if you don't use the smoke unit and you don't pull heavy trains.

 

[chris m01]

I'll be interested to know how you get on.

I have one Bachmann runnig Cb control and am very pleased with it. If only Cliff did a transmitter which could be switched to control different locos.

 

[chris m01]

I have done some testing with my 2007 model year GP30.
Test carried out pulling 6 USAT box cars at 18 volts track power. Scale speed approx 50mph
Amps drawn were as follows -
no lights - level track 1.8 amps, climbing 1 in 50 2.0 amps, peak on 12 diameter curve 2.3 amps
with lights on - 2.0, 2.3, 2.6
with lights and smoke - 2.4, 2.7, 3.0

Pulling 12 box cars (quite a long heavy train)
no lights - level track 2.2, climbing 1 in 50 2.5, peak on curve 3.0
with lights - 2.5, 2.9, 3.3
with lights and smoke - 3.1, 3.4, 3.7
This is using track power so the train engineer unit was probably taking 0.1 amp.

It would be wise to show these figures to Cliff before buying anything. If the lights are the same on current production and you have any gradients you are going to be getting very close to max power rating.

 

[Tony Walsham]

When converting any locos to battery power, the current draw of lights and smoke is only relevant if the whole loco is being powered by the output of the ESC.
In most battery installations these are powered directly from the battery and are not a load on the ESC output.
Typically I have found a good 3 amp ESC is adequate for powering the two block USAT locos.

 

[Bram]

That is a very helpful comment Tony many thanks for the post

 

[Bram]

How many motors in your GP30 Chris?

 

[spike]

How many motors in your GP30 Chris?

2

 

[Ian Powell]

Chris, Thanks for the information, I will certainly pass that on. I am still a novice with battery power.

 

[Ian Powell]

Well all the testing has been completed before any permanant fitting to the loco. The GP30 runs but only for a short time before the 21.5 v battery pack runs down. Chris was right, the amperage draw on the USAT diesels is rather high for the CB unit.
I have excellent results with Bachmann locos so the unit will be transferred to another loco.
If one does not experiment, one will never know the answer.

 

[Bram]

What do you class as a"short time" Ian and have you checked the the switch is working correctly, it doesn't take much heat from the soldering iron to upset 'em

 

[yb281]

That shouldn't be anything to do with the CB unit Ian, it'll either take the amperage or it won't. I'd agree with Bram, check your switches and battery pack condition.

 

[beavercreek]

I am in the process of batterising a couple or three USAT diesels as well as a co-co Aristo SD45 jobbie and to handle the amperage of the blocks, I am using the Revolution kit as it is not only very flexible, uses one small handset for all the locos, operates a bit like DCC (not by the technology but by the method), it also has the ability now to operate servos etc ( if it is needed) and it will operate some soundcards (Aristocraft have promised sound equipped Revo boards to be shipping fairly soon)

 

[Ian Powell]

What do you class as a"short time" Ian and have you checked the the switch is working correctly, it doesn't take much heat from the soldering iron to upset 'em

15 mins Bram. 18 new AA 3000 mah battery pack showing 20 volts when fully charged. All connections are secure. I seem to remember having a conversation with you and Mel that the wire used was not up to the job. Or was I wrong.

 

[Midwalesstokie]

If a 3000mah battery is running out in 15 minutes then the loco is drawing something like 12amps. Either the motor is very worn or something is wrong somewhere. Are the two motors wired in series or parallel?

 

[Doug]

AA batteries don't like supplying more than around 1 amp. For any higher current you are going to have to use 'sub C' sized batteries or Lipo batteries

I've used a 9 cell sub C battery pack (4.3amp hour cells) on my boxcab with a single USATrains motor block. It runs for around four hours pulling a long train.

 

[spike]

If most USAT locos are like the GP9, then they are capable of near 20Amps of stall current.
George Scheyer does a current limit article on his website that might help.
It's under his wheel pitting heading at.......
http://www.girr.org/girr/tips/tips11/wheel_pitting.html#pitting

I know the F3A and GP9 certainly do pit their wheels and sliders if you put em under any real load.

 

[steven large]

mine use nic cad battery..from battery recharge drill...BUt with out ciruct board

 

[Bram]

I agree with James, there is something amiss somwhere, you should be getting a longer run than 15 mins with that size battery pack.

 

[craigrailinc]

I have some barreries that are not needed.
Cre-55610 li-on battery 2amp 21.5 volt with cre-55620 power supply 4 batteries and two chargers and open to offers for them.
I ve also got Cre-55493 gell cell batteries. 6 volt 3 amp (think there are about 9). and the cre-55494 charger for brand new again open to offers.
i know nothing about running battery power.
please drop me a PM if you are interested.
Brian