I Spent alot of time investing in bike lights, I found that they're three types of bike lights commonly available online and in stores.
1) Well made cheap lights (£15-30) - These are pretty average. - Not chinese stuff, these are found on
Halfords especially. - Brightness is what people would call "enough" but not enough for my comfort on any decent speed on poorly lit roads. - Rear lights at this price however (just the rear) tend to be more than exceptional.
2) Chinese cheap lights. (£5-30) - These are exceptionally bright to an outstanding degree and reliability however is not as bad as you'd think, but for cycling specific lights of this kind, buying these lights tends to come with a catch - Most of the time, it's a battery pack made of the cheapest 18650 batteries you can call a "series" - or, dodgy chargers. Generally the lights are tip-top it's just the battery/charger thats flawed at this price point. (they have to cut corners.)
3) High end bike lights (£50-200) Most common on money-happy commuters and are from popular brands, these have the reliability and simplicity And good battery life, charging, etc - they tick all the boxes except for value for money.
There are other lights, but this is general assessment. -- I found no joy out of any of these methods and instead I went to buy everything separately. - I bought a torch that uses 4x 18650 batteries, (with a wide spread beam and about 3200 LM) the torch costs £20.00 - I bought the 4x 18650 batteries (From a very reputable and high-quality source) for £15.00 and a Very high quality battery charger. (£20.00)
Then, I went out and got myself a universal bike light clamp for £6.00 - It all went together very well for a reasonable price of £61.00 for something that now has insanely good battery life, power and simplicity.
Top is the new torch (advertised 3,200 Lm) - Bottom is the old torch - I ditched because of its poor spread. (1,400 LM confirmed on that one)
Run times for the new torch are about 2.5-3 hours on full beam, 4+ For everything else. It's very high quality as the price I paid for it was just for the torch, nothing else.
Very happy with the results and this has been running for a very long time now.