Once again I have a question for those who know more about electrical systems than I do.
Why are the unprotected Trustfire 14500s only working in battery powered blasters when they are inserted backwards?...
That's a really odd issue you got there, so far i have worked with more than 20+ Stampede
users locally who have done the exact same mods with the same modding materials and using the same TrustFire batteries... barring some odd units which were faulty (ie. erratic firing performance or weird circuit issues) which were simply exchanged at the store... all worked perfectly with the batteries installed in the correct direction.
I'd have to ask a rather obvious question just to narrow down the causes, did you place the batteries in the battery holder with their polarities facing the right way in the beginning? And were the wires from the battery connected to the correct polarity contacts in the battery sled?
Have you tested using AA to D battery converter shells instead? Did you encounter the same "need to be reversed then work" issue?
Do you have a volt multimeter with polarity indicator? If so, test the polarity of your TrustFire batteries, put the red test lead at the + tip of the battery and the black lead to the - tip of the battery, does it show the voltage without a "-" symbol next to the voltage reading?
Any chance you can exchange your current Stampede
with a new one at the store, or test the batteries in someone elses Stampede
and see if the phenomenon still occurs?
I'm quite curious 'cos you mention that you also face the same issue with your Powerstrike 48, which could indicate some sort of mis-matched polarities in the batch of batteries that you happen to be using too.