PowerBook 540c Main battery leak cleanup

[naryasece]

Hi,

I noticed I couldn't take out the battery in my 540c, so I took apart the case and found that the main battery had leaked pretty badly in the bay. I'm wondering if there is a way to clean up the corrosion and and stuff. Searching around I found articles and tutorials for alkaline batteries, but nothing specific for Ni-MH (actually most sites said it was very rare for Ni-MH batteries to leak badly). I found an article from Energizer (https://data.energizer.com/pdfs/nickelmetalhydride_appman.pdf) stating that the crystals are potassium carbonate, so perhaps a weak acid, like vinegar could clean it up? Some of the crystal build up looks green, my guess is that was corrosion from the copper leads?

Any tips for cleanup would be appreciated!

Thanks

 

[Papichulo]

try baking soda and alcohol. wow i never seen these batteries leak before 

 

[naryasece]

Papichulo, thank you for the reply; I think you're right about using baking soda and alcohol. I did some more digging and found a post about a 180c having a similar issue:

Ni-cad battery electrolyte is potassium hydroxide, and recommended cleaning solutions I’ve seen include baking soda, vinegar, and coke. Further research indicates that the blue color of the substance I found indicates that it’s copper sulphate and the recommended cleaning solution is hydrogen peroxide.

https://classicmacs.org/2010/06/powerbook-180c-acquired/

I picked up some (3%) hydrogen peroxide to try on the case and should have some baking soda around, I'll give those a try. Should still have some isopropyl alcohol around as well for cleaning the board. I'll post results when I get a chance to work on it.

 

[sutekh]

My 180c looked similar when I received it a couple of months ago. Although it was a leaky NiCd vs. NiMh, it had the same blue fuzz. There's some sort of thin metal finish that's been sprayed (or ion transferred or something) onto the inner surfaces of the chassis plastic which is, I suspect, intended to provide RF / EMI shielding. My take on the blue fuzz was that the battery's caustic electrolyte had been attacking that. Thankfully all of my PCBs were unscathed, but as Papichulo recommends, I had good success removing all of it with baking soda in solution and Isopropyl. Good luck!