Charging refurbished MacBook Pro

There should be no difference in how you charge a refurbished Mac vs new. You can open the System Information app, click Power, and check the Cycle Count to see how many times the battery has already been charged. If the cycle count is very low, like under 30 cycles, it's basically new with less than a month of use.

There are no special charging routines for a new device. Older devices used to recommend starting with a full charge and discharge (to "calibrate" a battery), but those instructions are no longer included with most new devices from most brands. Mostly due to improved battery management programming. Apple has removed all reference of battery calibration from the apple.com website, because they no longer think it's necessary.

Just use good battery health charging practices: Keep the battery cool (high heat is bad for it), aim for keeping the charge level between 40-80% a lot of the time, but don't worry about occasional excursions to 100% or 0% because the battery is there to be used.

Your Mac will never over-charge.

Leave it plugged in at least overnight.

https://www.apple.com/batteries/

The 40-80 idea is difficult to do in practice and generally reduces the utility of having a battery powered device. There are some battery powered devices where the user can select a setting that can limit the charge range automatically, but Apple doesn’t have such a setting.

Of course it's difficult to do 40-80%. That's exactly why I said to "aim for" (not strictly adhere to it), and then said "don't worry" in the next part of that same sentence. If you let it go to to 0% or 100% now and then as I already said in that reply, then you have not reduced the utility of your battery powered device in any way whatsoever.

But having that range in mind will help the battery last longer.

We do have this in common: We'd both jump on a post that treated 40-80% as some kind of strict religious standard that should never be violated. Sounds like we agree that's not a good way to get the most out of a laptop.

If someone is really insistent on having a battery last longer, but can live with short battery run times a strict “max longevity” setting would be a good way to do it. Since the dawn of hybrid cars, their batteries have stayed in a “sweet spot” where they never hit the extreme range of charge. Always enough to provide supplemental power, but not so much that it can’t absorb energy from regenerative braking. And strictly in a 35-75% (an example) charge range which keeps the battery in a range where there’s minimal loss of capacity. But Apple doesn’t have a setting like that, although I’ve seen other computers (including from Lenovo) that do.

I personally just leave mine plugged in most of the time. Life’s too short to worry about manually keeping a battery within a certain charge range. If I need to replace the battery, so be it.

That is certainly true in my case, since I often use my MacBook Pro a desktop, in closed lid mode connected to a hub and a couple of external monitors. Can't avoid it spending a few hours at 100% that way. It's been encouraging that I used my old MacBook Pro that way and never had to replace the battery in the 6 years it was in use. But I rarely let it go to 0% either. When it's not connected to my desktop setup, that's when I pay a little more attention to the charge range.

As you said, it would be nice if Apple provided some kind of charge range limiter like electric cars do. But it's not clear how much difference it would really make. If it was on by default, then default battery life would be shorter. But if it was off by default, the people who would benefit from it the most would have to know to turn it on.

If one uses the computer enough off-wall-charge making money, then a replacement battery may well be as often as the MBP needs replacement to keep up with business needs (someone I know who does use it to make money replaced a 2011 for a 2015 for faster CPU and RAM).

But wisely using the battery cycles always makes sense.

Your problem isn't clear. Is the computer running? Does it work on battery?