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Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 10:18 am
by Atarian Computing
So I'm also a fanatic MiniDisc user and one of the issues we face are obsolete Li-Ion batteries. NOS-batteries are already dead as they are over 10-years old. So someone came up with this solution, which was to use a much shorter, still manufactured, 10440 Li-Ion battery.

This feels wrong for some reason but I can't think of why. Thicker is better than thinner, or at least that's what she said. But a solid copper tube?
I was successful substituting the original Lib-902 battery of my AM-F70. At the moment it charges with the original charger that came with the AM-F70. If the original charger is not available you can easily charge the battery in a Li-Ion universal charger.

How to:
1.) Buy a 10440 cylindric Li-Ion battery (AAA format).
2.) Buy a 22 mm (length) x 10 mm (diameter) copper rod. I bought 23 mm but it was 0,5 mm too long. I had to shorten it with a file. With 22,5 mm at the moment the rod sits very firmly in the battery compartment and gives a lot of pressure on the lid. Maybe I will shorten it again. On the positive side the rod and the battery cannot move within the compartment.
3.) Insulate the copper rod with tape on the outside to prevent damage by short circuits!!!
4.) Put the copper rod into the battery compartment first (if not you cannot connect with the battery).
5.) Put the battery in the compartment. If rod or battery are moving too much, you can add tape to make them bigger.
6.) Close the lid and charge :-)

Advantages:
- No soldering
- Cheap
- No skills needed
- Interchangeable between different MD devices
- MD unit stays 100% as it is
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Re: Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 10:38 am
by exxos
"trust fire" :lol:

Well if it works..

Re: Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 10:50 am
by Atarian Computing
exxos wrote:
Mon May 20, 2019 10:38 am
"trust fire" :lol:

Well if it works..
They say it works fine. But there's no problem here? I would imagine that there is a point where it gets ridiculous though. I mean, a 1m3 huge copper block wouldn't work, right?

Re: Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 10:54 am
by exxos
Its just extending the + on the battery to fit, so work yes. Though it really doesn't matter, the copper should be on the 0V end of the battery.. but it wouldn't likely work as the insulation on the battery might isolate it. It should have insulation on it as well, but if being in a plastic housing, it probably doesn't matter.

Re: Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 11:24 am
by Atarian Computing
Ok, thanks.

Re: Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 2:14 pm
by rubber_jonnie
It looks like the same sort of batter my MD player had, which is like a flattened AA cell, so I kind of get how this works, but I'd be surprised if you can't buy an adapter, you can certainly 3d print one: https://www.thingiverse.com/thing:2137876.

My question would be, can the Lib-902, which is 3.6v, actually be replaced by a 1.5v AAA battery? In the case of that copper btw, I'd be insulating it.

Re: Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 3:18 pm
by DoG
rubber_jonnie wrote:
Mon May 20, 2019 2:14 pm
...My question would be, can the Lib-902, which is 3.6v, actually be replaced by a 1.5v AAA battery?...
Nope, it won't work. You replace it with a 10440 Li-Ion battery as stated in OP. It's 3,7V.

Re: Extending a AAA-size battery with a solid block of copper?

Posted: Mon May 20, 2019 3:35 pm
by rubber_jonnie
DoG wrote:
Mon May 20, 2019 3:18 pm
rubber_jonnie wrote:
Mon May 20, 2019 2:14 pm
...My question would be, can the Lib-902, which is 3.6v, actually be replaced by a 1.5v AAA battery?...
Nope, it won't work. You replace it with a 10440 Li-Ion battery as stated in OP. It's 3,7V.
Cool, hadn't noticed that.