[Randy Stone]

with voltage at 15.94 volts, the charger shut off at 120 mins.

I have to think it wasn't fully charges. Just timed out

 

[Randy Stone]

The 15.94 was what the charger showed when it kicked off.

The charger was on fast charger. 2.0 amps

 

[Randy Stone]

Sorry, the 14.8 volt pack is 7800 MAH

 

[Randy Stone]

I originally bought the 14.8 volt pack for the Dash 9 and at Marty's the loco couldn't pull a string og grain hoppers up the highline grade which is pretty steep. It would trip the overload in either the battery pack or electronics. After a few seconds it would reset and go again with help from a push by hand. It then kicked out and would need to wait a few seconds to start again. The loco which does not have but one small weight as supplied by Aristo Craft, never tried to spin the wheels. It just bogged down and shut off. This happened at least 3 times before getting up over the hump. So last year I bought a 18.5 volt pack. I didn't get around to pulling the grain hoppers, but pulled my 4 USAT streamline passenger cars up the highline grade several times without and issues. The loco still didn't have the speed I think it should have as others running Geeps were running a lot faster. In hind sight, I think I should have bought the 22 volt pack. Yesterday, I was pulling 26 coal hoppers and a caboose with the 14.8 volt pack. My layout is basically flat and I wasn't drying to go very fast so the 14.8 volt pack was doing the job.

By the way, while charging the 14.8 volt 7800mah battery pack yesterday at 2.0 amps (Fast Charge) for 120 minutes, I constantly was checking the battery to see it is was getting warm and it never did.

 

[Randy Stone]

One thing regarding batteries that has been on my mind is voltage requirements.

I hear all the time on this forum that the only difference between running a 14.8 volt battery pack and a 18.5 volt battery pack in a specific loco is maximum speed.

I am no battery expert, but I believe there is more difference than just speed.

There has got to be more torque available when powering a loco with a 18.5 volt battery than when using a 14.8 volt battery.

By that I mean, a Dash 9 should be able to pull more cars using an 18.5 volt battery than one using a 14.8 volt battery.

I really believe that if I had been using an 18.5 or 22 volt battery pack at Marty's when I was trying to climb the highline grade, the Dash 9 would either have been able to pull the load up over the hill or would have broke traction and spun the drive wheels.

 

[Randy Stone]

Rick

I understand the higher voltage pack will give higher speed, but will it not give more pulling power?

 

[Randy Stone]

Randy, as usual your question probably exceeds my ability to give a completely correct answer. I think that if your engine is not receiving enough power voltage and amps from the battery to overcome the drag of the train and the weight of the engine it will bog down and stop. From my experience the wheels will spin when there is ample power but the drag of the train exceeds the tractive effort of the engine. If the engine stops not enough power, if the wheels spin, too many cars.

Chuck

My exact thoughts Chuck.