The bad battery thread

MidnightMonkey

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Props on the thread. Just got the battery out of my new 2 slot. I'm wanting to run the battery away from the board in its own enclosure so I don't have to worry about corrosion at all. I'm just wondering if there's a maximum distance that I shouldn't go beyond with the wire which would lead to improper functionality?
 

Niko

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Props on the thread. Just got the battery out of my new 2 slot. I'm wanting to run the battery away from the board in its own enclosure so I don't have to worry about corrosion at all. I'm just wondering if there's a maximum distance that I shouldn't go beyond with the wire which would lead to improper functionality?

Nope, just make sure your wire is of an adequate gauge. Also storing batteries in an enclosure can be kinda dangerous. Is there a reason you prefer to not use a coin cell for replacement?
 

MidnightMonkey

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Well I want going to have it completely boxed up. More or less in a tray. And no particular reason for not going with the coin. It's not that it's not an option, I'm just trying to get as much info as possible before moving forward with my CMVS build.
 

Niko

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Well I want going to have it completely boxed up. More or less in a tray. And no particular reason for not going with the coin. It's not that it's not an option, I'm just trying to get as much info as possible before moving forward with my CMVS build.

Ahh ok, If your going toward a CMVS, I would definitely replace the standard battery with something else. Any 50ma or greater 3.6V battery should do you fine. The problem with the stock batteries is if there not constantly in use they start to break down and leak. This is why most people switch to a coin cell.
 

MidnightMonkey

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Sounds good. I'm about to submit this months order to DigiKey. Maybe the wife won't notice me buying a lot more than I'm used to.

So what Fygee said about solid state capacitors, I haven't seem any for sale on Digi-Key that I could find. Are they available for consumer use yet??? That would save a lot of hassle.
 

Niko

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Sounds good. I'm about to submit this months order to DigiKey. Maybe the wife won't notice me buying a lot more than I'm used to.

So what Fygee said about solid state capacitors, I haven't seem any for sale on Digi-Key that I could find. Are they available for consumer use yet??? That would save a lot of hassle.

Yea, you can get them on digikey. I think all super caps are drycell but not sure. The problem with super caps is they don't last long. They have a lifespan of like 1000 hours.
 

xsq

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Yea, you can get them on digikey. I think all super caps are drycell but not sure. The problem with super caps is they don't last long. They have a lifespan of like 1000 hours.
Do you mean lifespan or how long they hold a charge? AFAIK the supercabs with 1 farad charge up quite fast and can be used for a long time. I do not know how many hours they will provide enough energy to hold the data in BRAM with the board turned off though. Someone should try that out - it has been mentioned earlier that 3 months were claimed on youtube...
 

BLEAGH

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I was gonna change the battery on my 2-slot but those little pads on the bottom are really stuck on there. Any tips on removing them without taking part of the pcb with it?
 

grendelrt

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I just lightly cut into the hard portion on the top with a razor and then peeled it away.
 

MidnightMonkey

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I was gonna change the battery on my 2-slot but those little pads on the bottom are really stuck on there. Any tips on removing them without taking part of the pcb with it?

I just run hot water over them until the adhesive gets nice and loose and then peel/rub it off. The solder joints do a number on your thumbs but it's not that serious. Unless you got fragile girly hands.
 

Fygee

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A soft toothbrush, some lightly soapy water, and gentle elbow grease worked pretty well for me. The black foam on mine had crusted into a hard, semi-brittle caked mess so peeling it off wasn't an option. I managed to get just enough off to have a clear area for the battery solder points.

Just make sure you rinse it off with distilled water and let it dry when you're done.
 

Evilpoptart

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A soft toothbrush, some lightly soapy water, and gentle elbow grease worked pretty well for me. The black foam on mine had crusted into a hard, semi-brittle caked mess so peeling it off wasn't an option. I managed to get just enough off to have a clear area for the battery solder points.

Just make sure you rinse it off with distilled water and let it dry when you're done.

This, but I used a mixture of 90% isopropyl alcohol and distilled water. Mine was the same way, hard caked mess. It came off with some work
 

Fygee

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This, but I used a mixture of 90% isopropyl alcohol and distilled water. Mine was the same way, hard caked mess. It came off with some work

I considered using rubbing alcohol, but I was concerned that it would dissolve the protective coating on the board.
 

channelmaniac

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I considered using rubbing alcohol, but I was concerned that it would dissolve the protective coating on the board.

It won't. I use Goo Gone to remove the adhesive and it won't mess with the board either.
 

Ka0tiK

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I have no experience soldering but when I saw my 4 slot burning a hole through my board, I immediately reacted!

batt1.jpg

batt2.jpg

batt3.jpg
 

Niko

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nice save!

I hope you neutralized the area before installing the new battery. If not I would remove the new battery and holder, scrape up the damaged soldermask neutralize the area really well with baking soda. Then replace the C1815 transistor and the two resisters above/below it.
 

Ka0tiK

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nice save!

I hope you neutralized the area before installing the new battery. If not I would remove the new battery and holder, scrape up the damaged soldermask neutralize the area really well with baking soda. Then replace the C1815 transistor and the two resisters above/below it.

Area is well dry, so I didn't use baking soda though I have thought about scraping the green stuff but wasn't sure what kind of damage it would do. I'm not sure it's wise to invest any more time in repairing it because my slots are all crappy (not to mention I don't know how to solder) since the day I first got it - all I get is garbled images if the carts sway one way or another. For my first dip into the MVS, it was so disappointing. :(

Thanks for the advice!
 

Niko

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Area is well dry, so I didn't use baking soda though I have thought about scraping the green stuff but wasn't sure what kind of damage it would do. I'm not sure it's wise to invest any more time in repairing it because my slots are all crappy (not to mention I don't know how to solder) since the day I first got it - all I get is garbled images if the carts sway one way or another. For my first dip into the MVS, it was so disappointing. :(

Thanks for the advice!

Yea the problem is the acid gets under the soldermask and will actually start to run down the traces. If its already flaky, I'd just use it till it dies and then donate it for parts.
 

genetik

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I’ve just recently started to buy non-phoenixed CPS2 boards. This means that I had to swap out CPS2 batteries for the first time. What you see below is what I pulled out from my newly acquired 19XX and AvsP boards. It's kind of incredible that they were made 21 years and are still working. I've tested one, and it was still very close to 3.6V. Both are super clean, no leaks anywhere.

EDIT: Looks like I found a way to mess up something as simple as a battery swap :(. Both new batteries still give juice, but that didn't prevent 19XX from dying 10 days after the swap. AvsP took only one day to crap out. I just revived both of them using CPS2 decryption effort roms. I think I'll stick to doing this instead of battery swaps.

 
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delti90

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I picked up a dead six slot board over the weekend which has a green screen when I turn it on, from what I've found this is called calendar error? I went ahead and removed the battery and installed a button cell. It looks like the battery corroded the board a little bit, but all of the chips seem to be getting voltage from the new battery, the time crystal and D4990 specifically seem to be getting power from the battery. The corrosion doesn't look too bad to me, is there anything else obvious that I should try? I'm still new to NeoGeo so I don't know if it could still be the battery doing it?

Gksl1N2.jpg
 

Fygee

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The board should still function fine without a battery. If it doesn't boot up after the battery has been removed or properly replaced, then something else is going on.

The battery solder point looks pretty well corroded, and its harder to tell with the others as they appear to be covered in dirt/funk. I'd recommend cleaning the gunk off of the board so you can inspect it for corrosion and problems easier.
 
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channelmaniac

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Make sure you have 5v to pin 14 of the D4990 chip with the power on. If not, one of the traces from the battery section is damaged.
 
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