Anyone have battery soldering tricks?

[BadMouth]

One of the NES carts I'm giving my nephew for Christmas has a battery backup (Adventure of Link).
I'd like to install a fresh battery before giving it to him.  The reviews for batteries with tabs already attached make me leery of them.
I think I'm better off with a fresh name brand one.

I seem to end up soldering to coin cell batteries a few times a year, so I'm not new to it.  (just did the cmos battery in my laptop last month)
Basically, I scuff up the battery with sandpaper, apply liquid flux with a pen, solder the wire or tab, then try to solder that to the battery.
Getting it to stick always seems to take too long and the battery always gets hotter than I'd like.
Is there some trick to doing this that I don't know about?  (aside from using an ultra$onic welder)

[Howard_Casto]

You know, surprisingly, the batteries on my Zelda carts are still fine, and I bought them new BITD.  I even lost one of them in a snow storm when I was a kid, only to find it a couple of days later.  Do the batteries really wear out that often, or is it just a preventative measure?

[BadMouth]

You know, surprisingly, the batteries on my Zelda carts are still fine, and I bought them new BITD.  I even lost one of them in a snow storm when I was a kid, only to find it a couple of days later.  Do the batteries really wear out that often, or is it just a preventative measure?

Preventative.  I don't want him to lose progress on the game because the battery failed.
I opened the cartridge up, but I've been so busy lately that I can't remember if I measured the voltage on the battery already there.
I would think a 30 year old battery would be suspect.

[pbj]

I could never reliably solder to a battery.  You've got enough room in the cartridge case that you could run two rig wires to a battery holder and hide it all internally.....

Something like this:

https://www.amazon.com/Saim-Plastic-CR2032-Battery-Sockets/dp/B00SUVK6FK/ref=sr_1_7?s=electronics&ie=UTF8&qid=1513807382&sr=1-7&keywords=Cr2032+battery+case

[kane916]

pbj thats a great idea. idk why I never thought of that. I thought about replacing some batteries (just as preventative) before but my normal soldering sucks let alone trying on a battery. Will keep those in mind.   

[BadMouth]

The battery was still above 3v and I came across a post in another forum stating that the sram in the cartridge is probably good down to as low as 1.5v, so I'm not bothering with it.  The drain is so low that according to their calculations, the battery could theoretically last 70 years.  No idea if all their assumptions are correct, but it should be good for a few years to come anyway.

I'm still interested in tricks to soldering batteries if there are any.

Sent from my Life One X2 using Tapatalk

[pbj]

I've had to replace a few over the years... the Legend of Zelda battery made it almost 30 years.  Mystic Quest made it about 10.  Seems like I had to do was mention to a few friends that I had bought replacement batteries and they quickly disappeared.

 

[Slippyblade]

Do NOT try to solder on a button cell.  It will explode. (experience talking here)...  You can get those batteries with the soldering tabs already spot-welded very inexpensively.  Most likely at the local battery store, worst case, E-bay or Amazon.