Regret to hear that again
We have learned the lesson that to make the visible notice if there is without reverse polarity protection.
And here we again, to make the notice:
To use the battery WITH a PROTECTION CIRCUIT, to prevent reverse battery installation.
MAKE SURE the anode side towards the LED side when inserting the battery.
Otherwise, the light, ODF30, would be damaged when reverse installing the battery without a protection circuit.
As far as I understand it, the reverse polarity protection built into the battery is designed to protect the battery. It’s not designed to protect the flashlight circuitry. So I’m not exactly sure if a protected battery inserted backwards would save the flashlight or not.
That light by the way has a magnetic charger connection on the end cap. That’s why the battery is backwards in it. It is definitely the exception and not the norm for battery direction.
I have one light where the negative end of the battery gets inserted first. The makers put a very clear label on to light to show the correct orientation.
I don’t know if there’s room on the outside of the ODF30 to put a label like that. Maybe they can put a label inside the tail cap showing that the negative end touches the tail cap.
Picture right on the front of the instruction manual of the ODF30 shows the + end in the light and the - end sticking out the rear. Kinda easy to see and figure out. I tend to always check the manual for proper polarity, just in case I get one of the few lights that go tail positive.
Yes, most people should know that the positive always goes in the tube first and the negative goes towards the tail cap. Even though Lumintop has that picture above, I think they should make it a bit clearer.
Generally it could be said that most of my exsitance is an example of “Operator Error ”. If I fried my new flashlight it would have been because I was simply not paying attention to what I was doing.
I think every flashlight that uses lithium ions should come with a salesperson. Few people pay attention to signs. You should see how many people blow the red light at the off ramp by my job
I was used to push the battery positive into in the tube then screw the tail cap on my other lights ... except D20 has no tail cap and is filled "by the mouth"
For "electrical" (as opposed to mechanical) polarity protection, one has to insert something in the current path and this something will add resistance.
The "something" may be a simple diode but then the voltage drop is pretty high or something more sophisticated with MOS and polarity detection circuit but even the best MOS still add some resistance.
A very common theme in circuits is that they can be explained with a water analogy.
Battery protections are all basically valves.
A bathroom faucet can block or pass a small amount of current.
A bathroom faucet can block but not pass a large amount of current at a low pressure.
A creek sluice gate can block or pass a large amount of current.
In this scale — 7 amps in electronics the size of a coin — you need more of a sluice gate than a faucet. Not impossible but not trivial either.
It’s easy to become spoiled by modern high-performance devices and forget that the electronics are becoming somewhat brutalized by current to size ratios.