Battery guage light fluctuation

[4x4JeePmaNthINg]

The past few days ive noticed my battery gauge fluctuating 14 and a little below regardless of me being on or off the gas. a/c on or off as well as lights or radio. Upon hopping in and turning on the accessory the gauge sits just below 14 when it should be 14 even yes? as a charged batter should be....

I have replaced 4-5 interstate batteries over 9 years. the last battery i had interstate test and replace because the amperage was low and causing poor start. Currently im at 180000 about.
.stock alternator
.new well tightened serpentine belt
.plugs wires cap all new.

Ive had a reputable shop try and find the issue many years back but they "couldnt" trace what they believed to be something drawing power, so im not sure what kind of answer that is from " reputable" shop.

It is not regular for me to see the gauge to show a draw like this, mild fluctuation, a bar or two below 14 at most.

Is my alternator dying?
does it have to be removed to check?
What other possibilities could it be?

thank you for your help, if there is any other info i can provide to help please ask.

 

[2000XJSPORT]

My 2000 XJ battery gauge sits just very little below 14V as well. It has done it for years and I have been told it is fine. Let us know if you figure it out.

 

[ParadiseXJ]

My gauge is weird too. It'll sit well below 14...BUT the reading on my DVM at the battery is 13.9 The reading at the starter relay...13.9. The reading at my circuit breaker (power for my aux lights) is 13.9. When I turn the blower motor on...the gauge shows 11-12, but all those other spots show 13.9.

My headlights are bright and my battery is charged and ready to go every time I turn the key...holds at 12 volts even after a week of sitting.

 

[Hypoid]

Is my alternator dying?
does it have to be removed to check?
What other possibilities could it be?

I've had auto parts check my charging system by hooking a machine to the battery start the engine and go through a sequence of turning things on and off.