Agreed, you'll probably have a struggle to match the output of your striplight with an LED conversion, never mind a DIY job. Even if you could, the efficiency is unlikely to be much better.
According to
https://www.stouchlighting.com/blog/fluorescent-vs-led-vs-cfl you might manage at best 50 lumens/watt if you somehow optimise the retrofit perfectly. Not meaning just sticking some LED strips inside. Whereas you might expect 30 lumens/watt from a properly designed fluorescent fixture, which I think you probably have.
This is useful lumens out, not datasheet headline figures.
Hence my suggestion to just keep it and save hassle and expense. The tube will probably have a wattage consumption marked on it. Multiply that by 3/5 and that should give an indication of how many watts of LEDs might be required to match it, in a perfect world.
Not all LEDs are the same, there are still some pretty grim ones out there, generally you get what you pay for.
It took me three goes to find replacements that I was happy with, one of the basic 12V only simple ones literally burned out within hours when on hookup (seeing nearly 14.5V), a lot of the energy was just wasted in (under sized) dropper resistors, burning hot, and the output fluctuated significantly as the voltage dropped. I tested, and found they were taking nearly five Watts at nominal 12V. Maybe the LEDs were getting the specified 2.5W, the rest was just being burned up as heat. So much for efficiency, a total fail.
Horrible CRI (colour rendering index), important to me. I found the same with my cheap LED strips, though they didn't burn out, the heat being more distributed than in the tight clusters where they had crammed in as many LEDs as would fit, with no thermal path to take away the considerable heat. No sophistication, just cut to length, daisy chain together, maybe even add a correctly sized
fuse in case something shorts out along the strip. Highly unlikely admittedly, failure modes expected to be open circuit, not shorts.
AFAIK all the fixed voltage strips are just crude arrangements of LEDS in series with dropper resistors and associated inefficiency. The good ones don't do it that way, they are fed with an efficient constant current driver, but I've not seen those in use on 12V, and they are not inexpensive.
The clusters I finally chose are much more sophisticated, they have a regulator built in to cope with 12-24V nominal, I tested them and they held steady from as low as 6V to 30, where I stopped, and barely got warm.
Halogens, for all their relative inefficiency, deliver perfect CRI, a continuous spectrum, the closest thing to daylight. If you are critical about colour, studying photographic prints, paintings, other artwork, nothing else compares. That's why one of the lights over my table sometimes gets a halogen bulb put back into it, to study the photobooks that my partner enjoys making, and my hopeless attempts at painting.
Thank you all for your advice.
