Q: Storing an older Macbook

If you aren't going to use it, you may want to choose if you want to chance

the battery swelling up or going bad, and consider having it removed...

Even if not used a battery can go bad in storage. Plan on buying another

battery if you're going to store it for more than a few months; and if the

battery is from the original build date era of manufacture, it won't last.

PS: is this "...now unused 2008 MacBook...?" if this is true, consider its value

see what a spare battery may cost. They may be getting scarce. Which is it?

See the iFixit.com guide for Mac, your build model version, for battery removal.

Good luck & happy computing!

I would run the battery to about the 50% charge level, take it it out and place the MBP and battery in a low humidity environment.

https://support.apple.com/en-us/HT201725

Ciao.

Spot on advice!

HDs and SSDs should hold all data while just sitting, barring water intrusion or heat issues.  But low-humidity and temperature controlled should keep the HD/SSD safe.