Yes. After two or three years of use, you will find that the rechargeable batteries will go downhill rapidly. The old mUV light also had a rechargeable battery built in. It died about 2 years after I got it. Got so I was carrying around a “D” cell to operate it (I replaced it with the Adventurer when they were first released. One of the reasons I dislike “built in” rechargable batteries.)
They often start at around full capacity, but every use will cut this down a little. I believe most rechargable batteries are rated for around 50 uses at a full voltage. Time also enters into it because the batteries degrade over time. Usually, around 5 years, depending on usage. If the batteries have been wet or frozen (~25F,) this will also degrade them. I bought 10 extra rechargables for my old Adventurer and never used 4 of them. Two would not hold a significant charge when I put them in service. The other two worked about half as well as “new.” I switched to regular batteries. Though this was before the Li-ion batteries were out.