# Connection Break



## chucka (Mar 20, 2013)

Charging NiMH batteries in locomotives. The charging process starts (using a Tenergy Balance charger/discharger) and goes well for at least 30 minutes then the “connection break” message comes up. I understand if this message comes up instantly there is a wire break or something, but what does it mean when it comes up far along in the charging process and nothing is moved or disturbed physically with either the locomotive or the charger.


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## FatherMcD (Nov 13, 2015)

Have you checked with the Tenergy site for that error message? My first thought is something thermally related, e.g. a cold solder joint that breaks connectivity as it warms up. Is there a polyswitch or slow fuse in the circuit?


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## chucka (Mar 20, 2013)

I will check the tenergy site. No fuse. There is a switch for on off. Not sure what you mean about a polyswitch


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## Greg Elmassian (Jan 3, 2008)

thermal, self-resetting solid state "fuse"






Radial Leaded PTCs - PolySwitch - Resettable PTCs - Littelfuse







www.littelfuse.com





Greg


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## chucka (Mar 20, 2013)

Father McD and Greg,
Thanks much, when I setup these locomotives with batteries years ago, I used Remote Control Systems BIK-U3/6v2 Battery installation modules. When I saw the pictures you sent, Greg, I recognized that the modules did contain those components. I went and dug out the documentation and read—“1 x PCB with pre-mounted DPDT switch, 2 x Polyswitch ...”. So I now know what a polyswitch is and believe that to be the issue. I actually thought those were capacitors for some reason on the PCB. I guess I should change the tenergy charger from Auto mode to manual and charge at a lower and slower rate to see if that eliminates the issue or maybe eliminate the RCS units if they continue to create problems. Thanks so much for the enligtenment.
Chuck


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## chucka (Mar 20, 2013)

Well I changed the charger from auto to manual and lowered the upper current limit to 1.0 amp but I still get the connection break issue after charging a while. Should I j7st eliminate the polyswitch modules or are the battery packs faulty. They are quite a few years old and have been idle for many months previously


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## FatherMcD (Nov 13, 2015)

Do NOT eliminate the polyswitch! It's a "safety valve" in the circuit. I don't know the failure rate for polyswitches, but I would bet it would be far lower than batteries. Do you have any other battery packs you can try?


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## chucka (Mar 20, 2013)

I need to get some more battery packs but I think I might have one more to try


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## Greg Elmassian (Jan 3, 2008)

You can put a meter across the polyswitch (read volts) and see if it opens, the voltage will go way up.

Yes, the little buggers look like ceramic caps for sure!


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## chucka (Mar 20, 2013)

Thanks Greg. I will give that a try as well
Chuck


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## FatherMcD (Nov 13, 2015)

When you first set these locomotives up years ago, did they work then? What charger were you using and is that charger still available? I ask because looking at the instructions for Tenergy balance chargers (I don't know the specific model you have) they are designed to be connected directly to a battery that is "not installed in a device or electrically connected to other components." If you remove the battery from the loco and connect the charger directly, does it work then? If so, then there must be some interaction between the charger and whatever circuitry is in the loco that causes the error message. From that point, you'll have to decide how to proceed.


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## chucka (Mar 20, 2013)

I have the tenergy balancer/charger that does multiple battery types. I do not see a model number on it anywhere but looks like an earlier version of their current tb6b. I have some li ion batteries that I charged with it and it worked fine. I will remove the battery from the loco and try to charge it that way. I was able to charge the batteries in the units before. Maybe time to get new li ion batteries


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