Wierd Battery Voltage Test Results

First, I recommend just asusming the old battery is shot, pitching it, and not trying to explain what happened.  Theoretically, a battery could develop this behaviro if it had a tiny, intermitant interal fault across just one of its cell pacs.  I've never seen that, but . . . to me the salient point is " . . . I put in a 9 volt  battery, just a regular one; and Big Boy runs fine."

As to the traction tire.  My experience is similar.  I had an older Railking Y6B that threw all of its traction tires recently, when I ran it for the first time in a while.  I reinstalled them - and it promptly threw them again.  Once traction tires get to a certain age, they seem to loose the elasticity that kept them tight on the wheel.  Somewhere I have the box the loco came in and probably there is a pair of spares in there - but they will be the same age, although since never installed, perhaps with more spring left in then.  Anyway, newer ones are in order - except, like me, you could just remove them.  My RK Y6B runs and pulls fine without traction tires - so many wheels, so much weight - it gets by fine without them. 

NiCads have to be tested under load.  They can go over to the dark side and you can get very erratic results (we've seen this on laptop packs at work).  Some of the cells will actually report negative voltage.  

The batteries have a shelf life of about 5 years and/or so many charge/discharge cycles.  Once either parameter is exceeded (or some combination) the battery needs to be replaced.  In this particular application (aka a PS-1 loco) a BCR might be a better choice for the replacement.

The 5 year life was true for older NiCads, some (not all) newer ones are longer lasting in both time and cycles.

All that said, I agree with Lee, Replace the old battery, it's shot.

And Chuck is correct but I'd add this ; ALL batteries should be tested under load to get a true reading.

I'm not all that keen on the BCR technology for PS1, I like having the battery myself. It keeps me from forgetting to let the BCR charge for a full minute before running the engine.

Sounds like a bad battery. If it has PS-1, it needs a good battery that is fully charged before using it, otherwise you can damage the control circuit board.

With PS-2 you may get away with a weak battery for a little before it won't work, don't know if you can damage a PS-2 engine by using a weak battery.

Lee Fritz

If you don't go the BCR route, replace the battery with a NiMh type instead of a NiCad. You can get them at Radio Shack. NiMh batteries don't take a 'set' like NiCads can and they have a slightly longer shelf life.

Thanks guys!

I ordered a pair of MTH batteries and shouls have them in a few days.  In the meantime my train runs fine on a regular 9 volt battery.

When I get the new MTH should I put them at 15v for 18 hours in reset mode before using them?

Thanks also for the tip about the rubber tire.  There are some rubber tires in the loco box; and your note about age is also relevant.  The loco sat in my attic for 14 years, just got it out for Christmas!  I won't feel bad then, about just cutting the old tire off.  Maybe I will try one of the new old ones but if they are like rubber bands I doubt they will be any good.

For the tires, sometimes the wheel gets oil/grease in the groove and this allows the new tire to slip off.  Also if the tire isn't completely in the groove (edge on the rim) it can slip off again.  Make sure you clean the wheel/groove before reinstalling a new tire.

Weak batteries don't "physically" damage the boards, but they can cause a software/memory issue on some boards/chip combinations.  They can be restored by MTH Techs.  G

David, you should charge the batteries before you use them.  Rubber bands last longer if you keep them in a sealed container.  I assume our toy train traction tires would do the same.

If you get tired of replacing traction tires send me an email and I will send you instructions on how to replace the tires with silicone sealant.  I don't replace traction tires anymore, I use the silicone sealant.

Incidentally, any battery that registers 5.6 volts is dead.  An 8.4 train battery would have to register above 8.4 volts to be any good and at that point needs a charge.

.....

Dennis