Thanks for the heads up for everyone who has an old Toshiba laptop, although I would like to note that Toshiba isn't the only brand prone to this issue. I have an NEC Versa FX laptop that uses the same dreaded green cell RTC battery of doom, as someone who has taken these laptops apart during his childhood, I took note of that, so I recently opened it up to remove the CMOS battery, it was the right time to do so because it was just about to leak.

I know a lot of Dell laptops from that generation and later (including the Latitude C-series and their Inspiron counterparts) have used those batteries.

I'll be sure to remove the CMOS battery (or batteries) from my Toshiba Tecra 720CDT very soon. I've already removed the batteries from my Toshiba Satellite 315CDS so I don't have to worry about that one.

Off-topic: this is my 423th post (might be worth mentioning when post counts correspond to a socket model (in this case: Socket 423)).

Thanks for the information, I did not know that NECs and Dells were also susceptible to this problem. I'm sure that besides Toshiba, NEC and Dell, a lot of other brands will also suffer from this.

I usually open all old computers right after I buy them, doesn't matter the brand and model, to clean them and to check if everything is ok. I guess the lesson here is to also always remove anything that is prone to leaking sooner or later.

so sad, my toshiba has the same green batteries
i removed them and never put new ones

I like to use a mild acid or acidic solvent to clean those battery corroded boards.

Like Vinegar and then Ethylacetate.

You should neutralize it somehow. You can also use destilled water a couple of times to rinse it. But be sure to dry it well.

Edit: I think it is unlikely but not impossible that it will work again after cleaning. check the boards for potential broken traces or corroded copper parts like IC legs etc.
If you can't see any damage, prepare for a long multimeter session.

@BLockOUT I do the same in all my hardware, soldered or socketed, I remove the batteries (even lithium ones) and never put new ones. It's safer that way.
I also remove those capacitors used to store information or keep time, like the ones used on the original Xbox.
If a battery is required, I try to solder some wires leading to a socket where a CR2032 can be placed, that way I can remove the CR2032 when I'm not using it.

@mcobit I started to clean the Tecra, because it is the one in better shape and I don't want it to deteriorate even more. I will try to start cleaning the Satellite next weekend. I don't have ethylacetate, but I'm going to use vinegar like you suggested to remove the corrosion, and then I'll clean with ethyl alcohol and destiled water.

Thank you.

This weekend I got to work on a laptop that I have, a Compaq Armada 7380DT.
This is one of those Compaq laptops that has a strange PSU connector, fortunately I have the PSU.

The laptop never worked, but the PSU seems to be working. Anyway, I finally found time to open it up. I discovered a battery of doom, leaking all over the place.

Will clean it all up when I have time, I hope I can fix it. It has a Pentium MMX 266Mhz and ESS ES1878.

------------------

About the Toshibas, I started cleaning the Satellite with cider vinegar (I didn't have white wine vinegar). I tried to remove all those corroded blue/green spots from the circuits with a toothbrush and vinegar, but some of them didn't come off. Should I scrub them harder until they come off, or is it OK for some of them to stay?
The blue/green corrosion, is it toxic? Should I wear gloves?

After that, I removed the vinegar with bi-demineralized water. In the end I cleaned the boards with ethylic alcohol.

I have an Omnibook 800 with a dead CMOS battery but function-wise it doesn't matter at all since the battery (the big one) also holds the BIOS and time settings etc.
I know, this topic is about leaking batteries but if you're like me and aren't really good at taking things apart, it might be a better idea to leave the laptop as it is, because plastic can become brittle and break and then you might end up with a broken case even though the battery wasn't even leaking.
Not all batteries leak and even if they do it doesn't necessarily mean that anything important will be damaged so...

NoNameNeeded wrote:

I have an Omnibook 800 with a dead CMOS battery but function-wise it doesn't matter at all since the battery (the big one) also holds the BIOS and time settings etc.
I know, this topic is about leaking batteries but if you're like me and aren't really good at taking things apart, it might be a better idea to leave the laptop as it is, because plastic can become brittle and break and then you might end up with a broken case even though the battery wasn't even leaking.
Not all batteries leak and even if they do it doesn't necessarily mean that anything important will be damaged so...

I had to break a little bit of the Armada 7380 DT case, because the battery had fully corroded one of the screws and I couldn't unscrew it 🙁
I should have used a driller to drill the head of the screw instead of cutting the plastic around the screw in order to remove it.

But I rather damage a little of the case instead of leaving the batteries inside. According to my experience, nothing good will come from leaving the batteries inside 🙁

My working Compaq LTE5000 series laptop is kept stored without ANY battery at all, when i got it it had his nicad cmos memory starting to leak, i guess i had good luck it only spread to the plastic casing of the battery.
Even my mobos with CR2032 batteries are stored without the battery, its pretty hard to CR2032 to leak but better be safe than sorry.
A nice way to sotre them are in a ESD safe plastic bag without the battery and some silica gel packs inside a black box on a place without heat.

.legaCy wrote:

A nice way to sotre them are in a ESD safe plastic bag without the battery and some silica gel packs inside a black box on a place without heat.

That is a very good way of preserving your hardware. I store mine in a closed room with a dehumidifier (I only need to turn on the dehumidifier on Winter). I try to keep most of them out of the sun, but space is limited. I usually place towels on top of the ones that catch sun.
The batteries I remove and close them inside not ESD safe plastic bags.

I still haven't finished dealing with my other laptops, and I already have more.

This time it's a FIC (First International Computer) DESIGNote 5200CDT / 5220CDT - Leo Cedar, same problematic batteries:

The battery was leaking, but the laptop still works. I removed the battery (and I'm going to clean the leakage as soon as I end dealing with my other laptops). More information about this laptop here:
Re: Leo Cedar - laptop with logo similar to Peugeot

peido wrote:

.legaCy wrote:

A nice way to sotre them are in a ESD safe plastic bag without the battery and some silica gel packs inside a black box on a place without heat.

That is a very good way of preserving your hardware. I store mine in a closed room with a dehumidifier (I only need to turn on the dehumidifier on Winter). I try to keep most of them out of the sun, but space is limited. I usually place towels on top of the ones that catch sun.
The batteries I remove and close them inside not ESD safe plastic bags.

I guess i didn't wrote in a clear way, i store all my hardware without the batteries and inside ESD safe, the hardware is stored this way, not the batteries, i store old batteries on a separated plastic container that usually go to proper battery disposal services.

Btw where i live it is the opposite, the summer is hot and wet and the winter is still hot but very very dry(esd discharges happen more often than corrosion/oxidization because of the humidity).

More two Toshibas...

A Toshiba T2130CS:

And a Toshiba Satellite Pro 440CDX:

I find the inside of the Satellite Pro 440CDX very similar to the Satellite 230CX.

The first laptops I found without batteries leaking, but I removed them the same. It's best to prevent.

.legaCy wrote:

I guess i didn't wrote in a clear way, i store all my hardware without the batteries and inside ESD safe, the hardware is stored this way, not the batteries, i store old batteries on a separated plastic container that usually go to proper battery disposal services.

Btw where i live it is the opposite, the summer is hot and wet and the winter is still hot but very very dry(esd discharges happen more often than corrosion/oxidization because of the humidity).

Thanks for the clarification.
It's great that you have your hardware properly stored 😀 I hope that feature generations can appreciate what we preserved.

I didn't know that ESD discharges could be such a problem 😵

I've disassembled and repaired many laptops from the 80-90's era and I've found that the majority of these classic laptops/notebooks all have some from of leaking issues with the batteries and capacitors. Sometimes a battery may look fine but on closer inspection if you follow the wires from the battery to the board connector, the acid has travelled through the wire and onto the board. Only a slight leak is required to corrode the tracks and if the board is a multi-layer board the repair is not going to be easy.

I find it is always a good idea to replace internal backup batteries with the same type and not to just attach a CR3032 as this would
then affect the charging circuit if there is one and is also prone to leaking if it is a cheapie. A much better solution is to use a super capacitor or a large value capacitor in place of the battery. A super capacitor will not leak and to extend the amount of charge the capacitor holds, a 10k resistor could be used for current limiting.

Just my 2 cents on the issue.

peido wrote on 2018-07-25, 10:39:

This weekend I got to work on a laptop that I have, a Compaq Armada 7380DT. This is one of those Compaq laptops that has a stran […]
Show full quote

This weekend I got to work on a laptop that I have, a Compaq Armada 7380DT.
This is one of those Compaq laptops that has a strange PSU connector, fortunately I have the PSU.

Compaq Armada 7380DT PSU connector.jpg

The laptop never worked, but the PSU seems to be working. Anyway, I finally found time to open it up. I discovered a battery of doom, leaking all over the place.

Compaq Armada 7380DT leaking battery and damage 1.jpg Compaq Armada 7380DT leaking battery and damage 2.jpgCompaq Armada 7380DT leaking battery damage 1.jpg Compaq Armada 7380DT leaking battery damage 2.jpg

Will clean it all up when I have time, I hope I can fix it. It has a Pentium MMX 266Mhz and ESS ES1878.

------------------

About the Toshibas, I started cleaning the Satellite with cider vinegar (I didn't have white wine vinegar). I tried to remove all those corroded blue/green spots from the circuits with a toothbrush and vinegar, but some of them didn't come off. Should I scrub them harder until they come off, or is it OK for some of them to stay?
The blue/green corrosion, is it toxic? Should I wear gloves?

After that, I removed the vinegar with bi-demineralized water. In the end I cleaned the boards with ethylic alcohol.

Hello,

I randomly found this link..you have the similar notebook like me - Ihave Compaq Armada 7360DT. Unfortunately I dont have a power adapter, the one with a strange PSU connector. I would like to ask you for a help. Can you measure a voltage of each pin of the PSU connector?

Have a nice day,
Dave

Dave Bursik wrote on 2021-02-19, 14:08:

Hello, […]
Show full quote

Hello,

I randomly found this link..you have the similar notebook like me - Ihave Compaq Armada 7360DT. Unfortunately I dont have a power adapter, the one with a strange PSU connector. I would like to ask you for a help. Can you measure a voltage of each pin of the PSU connector?

Have a nice day,
Dave

Hi!

Yes, no problem.
I'll try to do that this weekend.

BTW, it might be easier to solder some wires on the battery connectors of the Armada and connecting a power supply to those wires (simulating a battery). I believe I've seen some people doing that on Compaq LTE and SLT (I'm also planning to do this on my old Compaqs, I don't have the PSU for them).

I hope that your laptop works.

I will add some to that list. But as was stated earlier, everything that has batteries can be damaged at some point (though I think that mainly Ni-Mh and Ni-Cd are prone to leak, lithium batteries not so much).

Laptops with Ni-Mh batteries:
Toshiba Libretto 70CT/100CT/110CT (and one of them has leaked)
Texas Travelmate 4000M (leaked)

Post 2000- laptops still using Ni-Mh batteries:
Dell Inspiron 8100/8200 - pretty big battery under keyboard. Didn't leak, but that would be a huge mess if it ever does.
Dell Inspiron 8600 - battery has it's own compartment, it's under a lid next to the main battery. It didn't leak, but even if it leaks, it probably won't be super disastrous.

And something interesting: Siemens Nixdorf PCD-4/5ND. 486/Pentium 1 laptop with rechargeable lithium battery soldered to the mainboard. I don't think that they are prone to leak as much as Ni-Mh.

peido wrote on 2021-02-20, 13:45:

Hi! […]
Show full quote

Dave Bursik wrote on 2021-02-19, 14:08:

Hello, […]
Show full quote

Hello,

I randomly found this link..you have the similar notebook like me - Ihave Compaq Armada 7360DT. Unfortunately I dont have a power adapter, the one with a strange PSU connector. I would like to ask you for a help. Can you measure a voltage of each pin of the PSU connector?

Have a nice day,
Dave

Hi!

Yes, no problem.
I'll try to do that this weekend.

BTW, it might be easier to solder some wires on the battery connectors of the Armada and connecting a power supply to those wires (simulating a battery). I believe I've seen some people doing that on Compaq LTE and SLT (I'm also planning to do this on my old Compaqs, I don't have the PSU for them).

I hope that your laptop works.

Thank you for your help. What I know now:
Upper left pin=GND
Upper right = 18.5V
Down left = ??
Down right = ??

About battery connector..do you know the connector pinout ?

Thank you very much.
Unfortunately I expect the laptop is dead...

Dave Bursik wrote on 2021-02-20, 14:12:

Thank you for your help. What I know now: Upper left pin=GND Upper right = 18.5V Down left = ?? Down right = ?? […]
Show full quote

peido wrote on 2021-02-20, 13:45:

Hi! […]
Show full quote

Dave Bursik wrote on 2021-02-19, 14:08:

Hello, […]
Show full quote

Hello,

I randomly found this link..you have the similar notebook like me - Ihave Compaq Armada 7360DT. Unfortunately I dont have a power adapter, the one with a strange PSU connector. I would like to ask you for a help. Can you measure a voltage of each pin of the PSU connector?

Have a nice day,
Dave

Hi!

Yes, no problem.
I'll try to do that this weekend.

BTW, it might be easier to solder some wires on the battery connectors of the Armada and connecting a power supply to those wires (simulating a battery). I believe I've seen some people doing that on Compaq LTE and SLT (I'm also planning to do this on my old Compaqs, I don't have the PSU for them).

I hope that your laptop works.

Thank you for your help. What I know now:
Upper left pin=GND
Upper right = 18.5V
Down left = ??
Down right = ??

About battery connector..do you know the connector pinout ?

Thank you very much.
Unfortunately I expect the laptop is dead...

COMPAQ ARMADA 73xx and 74xx (7360 , 7380 , 7400 , ....) - PINOUT OF POWER SUPPLY (PSU) CONNECTOR

https://imgur.com/a/0ftizzH

-------
| 1 3 |
| 2 4 |
\____/

1 - +18,5V (19V will work too)
2 -
3 - Ground
4 -

Betwen 1 and 4 connect 2,2kohm resistor.