@ chicken Drumstick
Thanks for the reply. I was reading about how to mod a P7 on the internet and how awkward it was when I came accross the excellent info post here, LEDs & Other Stuff - (Reference Guide) .
The original LED was an XR-E, but I’m happy to swap it out. I have soldering, pcb and electronic design skills and am willing to use them for this. I will be happy if the outside remains unaltered, but the inside can be completely changed. The reason I asked about 6v or two led in series configuration is that it would be easier to use a boost convertor for power. The P7 uses a couple of switched resisters on the lower pcb so the torch output was never even over the relatively short 4aaa battery life.
My issue with the single led solutions you suggest is that the Voltage across the LED is high relative to the normal battery voltage. I have also noticed that the voltage figures given are at 85C, which is all very well, but I suspect the voltage across the LED at normal ambient, say 20C is almost equal to that of a half discharged Li ion cell, leaving no room for current regulation. Do drivers exist which will buck and boost?
Also seem to be having trouble removing the LED/mount/other electronics from the aluminium tube. I have removed the white plastic LED clamp/cover with its star head screws revealing the LED sitting on an aluminium pillar in the centre of it. I thought these just screwed in. It may jut be tight or it could be bonded. If bonded as I suspect I have two options, a debonder chemical or machine it out (possibly just the centre) with a mill, destroying the insert.
OK I have just managed to remove the LED holder and its electronics from the tube. It is threaded but sealed with what appears to be an epoxy. I used a hot air gun and heated it to around 300C before it would undo. Outer tube is undamaged so its all looking rather good.
Best Regards
picclock