Inserted battery in wrong way

I'm new to 18650 flashlights. So I recently purchased a T20 Infrared illuminator (single celled ultrafire torch customized with IR pill) from ebay. Being ebay and a customized torch, it didn't come with instructions. I opened it up, saw the spring at the top near the the head and inserted the battery negative end to the spring. Nothing happened when i looked through my night vision, so I thought maybe I got a defective IR illuminator or maybe I need button tops as the batteries I purchased were flat top. After a bit of googling, found another seller for t20 ir which specified positive end should be towards the head, and most torches being positive towards the head. So I corrected the orientation and it worked fine no problems.

My question is, do you think the t20 got damaged (e.g. less illumination than normal) when i inserted the battery the wrong way around? I did it a few times trying to get it to work. Do you think the battery got damaged and is potentially dangerous? The battery I used was a sanyo ur18650fm 2600mah unprotected, I ordered the protected ones from gearbest, unfortunately they mistakenly sent me the unprotected, so I chose to get the free refund and use the unprotected.

The t20 seems to work fine, battery charges fine in the xtar vp2. Just want to check if i'm putting myself at risk by continuing to use a battery that has been inserted the wrong way. Also want to check if the t20 is no longer working at its full potential so I might decided to buy another one.

Hard to tell if it is dimmer if you don't have another one to compare it to.

Since the light turns on and still works, there may have been some reverse voltage protection on the light. As for the battery, I'm thinking it should be OK, but I'd wait for someone else to chime in as well.

:welcome:

If it damaged the light, your light wouldn't work at all now because the electronics would be fried. As for your battery, it should be fine because there was very little current (or any at all) being used when the cell was reversed. If it had shorted or something like that, your light would be fried too.

If there is a collar around the spring in the head, then there was no damage at all as there was no connection. If there is no reverse polarity protection collar, then there was reverse polarity protection in the circuit.

more_vampires said:

If there is a collar around the spring in the head, then there was no damage at all as there was no connection. If there is no reverse polarity protection collar, then there was reverse polarity protection in the circuit.

Click to expand...

some photos of it, since I don't know what i'm looking at.

Ohh, the brass thingy in the tail cap is called a "pogo pin." That's actually pretty nice.

No reverse protection collar in the head, bare spring.

Thank you all, for all the help, appreciate it.