How to remove battery acid from boards ?

[Vifa]

Hi

I have been changing some of the CMOS batteries in my old computers, but the old batteries had leaked acid on to the board. How do I clean this ?

 

[tezza]

I haven't done this myself but would a weak alkaline solution (Sodium bicarbonate?) help?

Tez

 

[Chuck(G)]

Unless the battery is carbon-zinc or lead-acid, it's not acid---it's alkaline. Use white vinegar and follow up with water.

 

[Vifa]

Thanks for the replies.

I will try it out tomorrow and post a update here.


Btw, the old battery was a Ni-Cd, and the new one I ordered came as a Ni-Mh. Is that a correct replacement ?

 

[FishFinger]

As long as the voltage is the same then there's no difference worth worrying about.

 

[Vifa]

Update

Update

Hey, I tried with white vinegar and water yesterday.

Some of the lanes on the board is no longer green anymore, and a strange dark spot has suddenly occurred.

 

[Chuck(G)]

The green stuff is the layer of solder mask on the board--and the dark spot is the PC board itself showing through. Neither is of real concern, but check the continuity of the traces. Battery electrolyte can and often does dissolve copper traces, though not as aggressively as cat urine (don't ask).

You can protect the traces and the board with some clear nail polish. Or, you can use a commercial solder mask that should do a better job of matching the green color of the original:

 

[Vifa]

Thanks a lot !

 

[Ec1564]

Get a can of PC board cleaner(Tech wash or equ), that will clean off most of acids and other not so PC board friendly stuff. Using vinegar or baking soda will leave residue(after a good rinse too) and will make more problems down the road. I lost a few motherboards that way. Just make sure the cleaner you get is safe for "most" plastics, there are a few that will eat up plastics really fast!