Several questions regarding BT40S

I am looking for a bicycle light and BT40S caught my attention, but so did some questions pop up along with it…

1.) I’ve seen two brands having BT40S - Revtronic and Nitefighter - what’s the difference between the two, if any?
I’ve noticed Revtronic used to sell Nitefighter BT40S before, but now they’re selling BT40S under their own brand name…

2.) Is BT40S still a way to go light for bicycle night rides or some new (better?) alternatives emerged in the meanwhile?

3.) Who is the original manufacturer of those and where can one find the parts for these lamps?
I like to keep spares, so I’ve been specifically looking for straps, lenses, o-rings and such, but on GB I get the option to either buy the bare unit without the rest of the bundle (does that option really include nothing but the unit itself?) or the full bundle which is more than double the price - that especially makes no sense for someone who goes just after the specific spare parts…

4.) In case you’re not using the battery pack supplied in “full bundle”, what kind of pack you use to power this light up?
I’d like to build my own battery pack from the batteries I will buy specifically for this purpose, and therefore I am sure I can build a better one than the one supplied - all suggestions are welcome!

There’s a huge thread at MTBR/lights and night riding. It’s a decent light, I have the revtronic bt40 and it works great. Problem is, I have several bike lights that are much better.
It’s a good light for the $37 I paid for it.

I have a BT40. revtronic is the manufacturer that used to sell it as nightfighter. it’s an ok light however, I’m not too into super floody lights so it has been sitting unused for a while. Revtronic used to sell the full set on ebay at better prices than amazon ($54 ish) If you are able to do some soldering, consider a battery box like this. (sorry, i can’t remember if the plugs matched up initially because I changed mine a while ago.) You can choose which ever cells you want and be able to charge them separately in a good charger.

BTW, my current cycling light is a imalent dm21 (older version), with a NW LED for 99% of use, or a convoy C8, modified with an XHP50 LED, and external battery pack for extra brightness and longer battery life. (I zip tie the lights to the helmet)

I’ve read the whole MTBR thread and the one here with a couple of modded BT40S, but I was wondering if anything changed in the meanwhile and if there is any additional light I should know about that gives that much for that money.

I’ve considered modding one Convoy C8 and XHP50 does sound nice, but I am worried about the heat and how long the juice can actually last.
If I am to bring a battery pack too, I might as well stretch a little and go for the BT40S which should outperform C8, am I right?
Originally I thought of having BT40S for flood and a thrower on helm, if it proves to be necessary.

Does “a bare” option really come with no additional lenses/o-rings and such?
If so, what about the spares then and how does one get a hold of them without buying the whole pack for just the spares?

I have a Revtronic BT40S too. It is an excellent bicycle light. Very powerful and every things are included with its package. Also in my country it costs me less than $US 60. The real best bang for the bucks. If I did not know where it came from before, I would think it made in Germany. Very neat and very nice indeed.