Computer battery> Is it better to leave it out of the computer if it is never used except when traveling .?

The main damage to the battery comes from the amount of heat the laptop produces while in use. If it's easy enough to remove, then you should go ahead and remove it.

if being stored for at least a month, you should discharge the battery to approx. 75% before removing. leaving it fully charged may damage it if left for a long time.

It doesn't help your battery one little bit one way or the other if you're not using it it's just sitting there it's not burning up it's not charging it's completely neutral let it set where it's at it's not hurting anything

If a device with a lithium battery is going to be unused for several weeks, ideally the battery should be somewhere near half charge for optimal storage.

If it's a removable battery, take it out and put it somewhere cool until it is needed.

For long term storage (several months or things only used once a year) the battery manufacturers recommend setting them to around half charge then packing in airtight zip bags or containers and storing in a refrigerator (not a freezer!).

Allow them to get back to room temperature before unsealing them, to avoid condensation.

Stored like that the capacity loss should be no more than around 1% per year.

If you cannot remove a battery, charge to 60% then check every so often and top up back to that if it drops to 40%.

A battery allowed to stay completely flat for any length of time can be wrecked, and holding at full charge causes the fastest loss of capacity - and high temperatures make that worse.

(Some places advise keeping batteries fully charged all the time - either they are scammers trying to cause batteries to degrade rapidly, or they are confusing lithium battery requirements with NiMH / Lead-Acid etc., which are better kept fully charged).

[Professional electronics designer for many years].

No, never heard of such a thing.

There is no point in removing the CMOS battery. I've seen those last for years in computers that never get touched.

The Lithium Ion battery used in laptops doesn't need to be removed either. However, you should make sure it's at least 80% charged to keep the cells from dying.