SNES/N64/GB Battery leakage. Myth or reality?

Hello, since we are going to be the first generation in the history of videogames to collect them, we are also the first one to face up to some issues about preserving those items and I think that sometimes we are not properly prepared.

Even though the prices of some rare games are going very high, sometimes much higher then some vinyls or books, I noticed that the preservation of some videogames isn't always appropriate.
I mean, a guy who buys today a Donkey Kong Competition Cartridge today spending around 3000 USD the last thing he wants is to lose money because in 3-4 years the battery of the cartridge leaks or something else.
I know "nothing lasts forever" and bitrot is always on the doorstep, ready to ruin our memories and our precious ROMs, but are we sure we are preserving those cartridges properly?

Dumping a ROM is always the first step in my opinion, specially if we are talking about a prototype or something unique. But..what about the methods to preserve the cart from physical damages?

That's known we have to use a good environment with the right temperature, the right humidity and no voltages around but can we do something else? Or again, MUST we do something else?

Our PCB is a circuit with a battery inside, chips and resistors. Battery is something that has chemicals that can generate a charge and that is functioning h24. Do they leak or do they just slowly die without risking anything?

From what I can read around the web these batteries are solid so they cannot leak but there are also some photos of corrosion and leakage that seems to confirm that they can leak.

Should we remove the batteries from rare cartridges or prototype?

I think we should write some "guidelines" about preserving old rare memorabilia and games on PCB because we cannot risk in the future to lose some rare items from our collections. We are the pioneers in videogaming collecting and I think it's our aim to do the best we can.

Sorry for the long post but I wanted to share some doubts and some thoughts because I'm a bit worried

 

IMO if it's been backed up properly in its entirety, then there isn't anything to be overly worried about. It's been preserved - the contents are more important than the physical cartridge, right?

I think dead batteries should be removed (or replaced) but some people would argue that then it isn't "original". Touchy subject.

 

Carts use Lithium Metal batteries, they don’t leak. The ones to worry about are alkaline and carbon zinc disposables and Ni-Cd and Ni-Mh rechargeables. In other words worry about the Commodore Amiga first.
Li-ion batteries often swell when they fail in a high charge state, they should be stored at a 40% charge and separate from the device when possible, this is especially a problem with slim psp systems where it can break the battery cover latch on either the cover or system or on the vita where it can damage the rear touch pad

 

Shouldn't these rechargable devices be occasionally charged and used?
Li-on have a cut-off voltage. So if it goes below that, then the battery is dead. So even if it doesn't become bloated, the battery becomes dead and it makes handhelds... not so portable.

 

The first generation to collect video games is the baby boomers and I'm pretty sure "we" aren't boomers. You'd probably do best to look at what experts in the field are doing as far as preservation. Pontificating without knowing the basics isn't going to accomplish anything.

 

They also with age and charge cycles lose capacity.
My point assumes preservation of the device is top priority and that failure of a battery is inevitable. That’s a bit different from potassium hydroxide destroying traces and contacts or swollen batteries breaking the device beyond repair. Batteries should always be viewed as a consumable component that will fail. Common sense needs to prevail, in time all alkalines will leak ruining factory sealed game boys but replacing a battery in game cart just to put it in display box for 30 years is pointless too.