Replacement battery for Amiga and PC

[anda]

Hi!

I recently opened up two of my old computer as I was noticed about battery leakage. They both have the NiCd 3.6v 60mah barrel batteries. They had both leaked. So now I want to order a couple of new ones. I am not that keen on putting NiCd batts in them again. Rather use NiMH. But the only ones I can find are 80mah. Isnt 80mah too much?

Another thing is the charging. When the computers are turned on, they charge their batteries. But isnt the amigas(and maybe also the PCs) charging curcuit simple and just keeps charging even if the battery is fully charged and will that not dammage a NiMH battery over time?

[Kilrah]

It won't matter, both behave sensibly the same.
The NiMH might last less long though (as in go dead quicker).

[stj]

remove the charging resistor and fit a lithium coincell and holder.

clean up the leakage first with vinegar.

[Kleinstein]

I would not use vinegar for cleaning: it will cause corrosion much more than the liquid from the batteries. Just clean water an enough of it. If you like some IPA after that.

NiCd is usually less picky about the charging circuit. So if you still have or get some, why not. 

It may take more than removing the charging resistor to convert to non rechargeable cells. Sometimes the circuit might draw extra current when on . at least need to check that.

[stj]

water wont work, vinegar destroys alkaline without damaging the pcb or parts - then you flush it off with water.

[anda]

I have used vinegar and that takes all the blue and green stuff. After that I rub it with water. Perhaps I should use more water. One problem is that some has got under a chip and I dont have a desoldering staion with hot air. Hope the vinigar can get under there and do its thing without any rubbing.

[stj]

soak it.
i have put pcb's n a bowl of vinegar for a hour or more before in order to clear out through-hole plating and penetrate under chips.
you have to move it around a few times to *mix* the fresh vinegar with the dead vinegar that has been in contact with the alkaline.

just flush it under the tap after to remove the vinegar.

[Kleinstein]

For most metals the alkaline liquid is way less a problem than the acid from the vinegar. At best you get a slight cosmetic effect in having a not so blue surface, but any acid left will promote corrosion on copper / iron / nickle. The alkaline solution is only a problem for aluminum / titanium / magnesium and similar, but not to copper or iron.

Even if neutralized, the salt will still be hygroscopic. So you need a flush of water anyway.
Water is at least as good as vinegar and much less risk. It just washes away the alkaline solution like the salt you get after neutralization.

If you really want an acid to neutralize, phosphoric acid would the much better choice. As a quick fix one could try a coke.

[Tomorokoshi]

I have to do the same thing with an Amiga 3000. Thanks for the reminder.

I've used 409 to clean things, and then flush with water.

When I do the repair I'm going to remotely mount it so if it leaks again it will be out of the way.

[anda]

I just use a cotton ear swap with vinegar. Soaking seems a bit much. But perhaps I am to gentle. Next time I have to clean something after a battery leak I'll try using water only.

[stj]

For most metals the alkaline liquid is way less a problem than the acid from the vinegar. At best you get a slight cosmetic effect in having a not so blue surface, but any acid left will promote corrosion on copper / iron / nickle. The alkaline solution is only a problem for aluminum / titanium / magnesium and similar, but not to copper or iron.

i have been dealing with ni-cad leaks for decades, and seen them eat large tracks right through.
the science of destroying alkaline with a mild acid is well established.

[anda]

What about using flux to clean and neutralize the corrotion and neutralizing?

[stj]

flux is a vague word.

tinnnig the tracks afterwards is wise though.