Sony a9 battery leak
p.1 #1Sony a9 battery leak
Wonder if anyone has experienced battery leak inside their a9 or other cameras using Sony brand NP-FZ100 batteries.
Mine suddenly leaked inside battery compartment, ruining battery door seal, making on/off switch nearly impossible to move and who knows what other damage was caused by acid inside the camera.
I wrote to Sony and will see how they will handle it, but curious to know if this has happened to others and how it was handled.
Thanks all!
Below are the links to the pics of the battery etc:
https://ibb.co/JWV5KskC
https://ibb.co/0pyK20b8
https://ibb.co/HL8xV03h
https://ibb.co/7JhkkDVX
https://ibb.co/hJsj4Qfc
https://ibb.co/DDQ2qY86
Edited on Mar 30, 2026 at 06:40 AM · View previous versions
Mine suddenly leaked inside battery compartment, ruining battery door seal, making on/off switch nearly impossible to move and who knows what other damage was caused by acid inside the camera.
I wrote to Sony and will see how they will handle it, but curious to know if this has happened to others and how it was handled.
Thanks all!
Below are the links to the pics of the battery etc:
https://ibb.co/JWV5KskC
https://ibb.co/0pyK20b8
https://ibb.co/HL8xV03h
https://ibb.co/7JhkkDVX
https://ibb.co/hJsj4Qfc
https://ibb.co/DDQ2qY86
Edited on Mar 30, 2026 at 06:40 AM · View previous versions
Mar 29, 2026 at 07:31 AM
p.1 #2Sony a9 battery leak
I’ve been shooting Sony mirrorless cameras since 2013 with the introduction of the A7 and have owned every A7x, A7Rx, and both the A9 and A9II and the A1 and have never suffered the issue i think you are describing. I assume you have only used Sony branded batteries. I personally have only used a third party battery on rare occasions. I think we will all be interested to hear from you if Sony is able to diagnose what happened in your specific case. Let us know.
Mar 29, 2026 at 07:51 AM
p.1 #3Sony a9 battery leak
swldstn wrote:
I’ve been shooting Sony mirrorless cameras since 2013 with the introduction of the A7 and have owned every A7x, A7Rx, and both the A9 and A9II and the A1 and have never suffered the issue i think you are describing. I assume you have only used Sony branded batteries. I personally have only used a third party battery on rare occasions. I think we will all be interested to hear from you if Sony is able to diagnose what happened in your specific case. Let us know.
Yeah, I switched to Sony from Canon in 2015 or so, have taken my old a7II diving, no issues ever.
Only used Sony batteries on both A7II and A9. A year ago one of the old A7 batteries swelled a bit, just barely noticeable when Inserting it, so I threw it out - but that was after 10 years of use and it wasn't a leak.
In fact I've never encountered Li-ion battery leak in ANY device, camera or otherwise. Didn't even know they could leak.
I'll keep you posted on the developments
I’ve been shooting Sony mirrorless cameras since 2013 with the introduction of the A7 and have owned every A7x, A7Rx, and both the A9 and A9II and the A1 and have never suffered the issue i think you are describing. I assume you have only used Sony branded batteries. I personally have only used a third party battery on rare occasions. I think we will all be interested to hear from you if Sony is able to diagnose what happened in your specific case. Let us know.
Yeah, I switched to Sony from Canon in 2015 or so, have taken my old a7II diving, no issues ever.
Only used Sony batteries on both A7II and A9. A year ago one of the old A7 batteries swelled a bit, just barely noticeable when Inserting it, so I threw it out - but that was after 10 years of use and it wasn't a leak.
In fact I've never encountered Li-ion battery leak in ANY device, camera or otherwise. Didn't even know they could leak.
I'll keep you posted on the developments
Mar 29, 2026 at 08:06 AM
p.1 #4Sony a9 battery leak
I never had a leaking Li-ion battery. I had several that swelled, in some cases critical as the were difficult to remove from the camera. But no leaks. And my smaller Sony batteries were especially durable, my NP-FZ100 not old enough to give trouble.
The Sony batteries consist of two cells in row. This makes it necessary to balance them to avoid that the weaker cell gets weaker and weaker. This can be a point where third party batteries or chargers differ from the originals. Did you use third party chargers?
There are also fake copies of chargers and batteries around.
The Sony batteries consist of two cells in row. This makes it necessary to balance them to avoid that the weaker cell gets weaker and weaker. This can be a point where third party batteries or chargers differ from the originals. Did you use third party chargers?
There are also fake copies of chargers and batteries around.
Mar 29, 2026 at 09:26 AM
p.1 #5Sony a9 battery leak
Was it being charged inside of the body when it happened or was recently charged and put in the body?
Mar 29, 2026 at 09:30 AM
p.1 #6Sony a9 battery leak
ftllens wrote:
Was it being charged inside of the body when it happened or was recently charged and put in the body?
Recently charged and was in the body for a few days.
Picked up the camera, tried to turn it on, but the switch barely rotated. Tried taking the battery out, but the door was stuck - had to use a plastic prying tool to open the battery door. That's when I discovered that the battery leaked and melted the seal of the door. Battery itself had plastic melted as well - the part that normally has US & Canada Only marks is melted.
Was it being charged inside of the body when it happened or was recently charged and put in the body?
Recently charged and was in the body for a few days.
Picked up the camera, tried to turn it on, but the switch barely rotated. Tried taking the battery out, but the door was stuck - had to use a plastic prying tool to open the battery door. That's when I discovered that the battery leaked and melted the seal of the door. Battery itself had plastic melted as well - the part that normally has US & Canada Only marks is melted.
Mar 29, 2026 at 09:37 AM
p.1 #7Sony a9 battery leak
Never had that happen. *knocks on wood*
mt-m wrote:
Wonder if anyone has experienced battery leak inside their a9 or other cameras using Sony brand NP-FZ100 batteries.
Mine suddenly leaked inside battery compartment, ruining battery door seal, making on/off switch nearly impossible to move and who knows what other damage was caused by acid inside the camera.
I wrote to Sony and will see how they will handle it, but curious to know if this has happened to others and how it was handled.
Thanks all!
mt-m wrote:
Wonder if anyone has experienced battery leak inside their a9 or other cameras using Sony brand NP-FZ100 batteries.
Mine suddenly leaked inside battery compartment, ruining battery door seal, making on/off switch nearly impossible to move and who knows what other damage was caused by acid inside the camera.
I wrote to Sony and will see how they will handle it, but curious to know if this has happened to others and how it was handled.
Thanks all!
Mar 29, 2026 at 09:49 AM
p.1 #8Sony a9 battery leak
Altglas wrote:
I never had a leaking Li-ion battery. I had several that swelled, in some cases critical as the were difficult to remove from the camera. But no leaks. And my smaller Sony batteries were especially durable, my NP-FZ100 not old enough to give trouble.
The Sony batteries consist of two cells in row. This makes it necessary to balance them to avoid that the weaker cell gets weaker and weaker. This can be a point where third party batteries or chargers differ from the originals. Did you use third party chargers?
There are also fake copies of chargers and batteries around.
Sony original charger and the original battery that came with the camera.
I never had a leaking Li-ion battery. I had several that swelled, in some cases critical as the were difficult to remove from the camera. But no leaks. And my smaller Sony batteries were especially durable, my NP-FZ100 not old enough to give trouble.
The Sony batteries consist of two cells in row. This makes it necessary to balance them to avoid that the weaker cell gets weaker and weaker. This can be a point where third party batteries or chargers differ from the originals. Did you use third party chargers?
There are also fake copies of chargers and batteries around.
Sony original charger and the original battery that came with the camera.
Mar 29, 2026 at 10:03 AM
p.1 #9Sony a9 battery leak
Approximately, how old is the battery? There should be a date stamp on it. And, is this really a genuine Sony NP-FZ 100? My understanding is, there are fake batteries, parading as genuine...
Mar 29, 2026 at 10:07 AM
p.1 #10Sony a9 battery leak
AGeoJO wrote:
Approximately, how old is the battery? There should be a date stamp on it. And, is this really a genuine Sony NP-FZ 100? My understanding is, there are fake batteries, parading as genuine...
Yes, genuine, the one that came with the camera originally. So 2019 if not older. Don't really see a date stamp, just some random numbers
EDIT: It says 20180717WBA, so 2018 I guess?
Edited on Mar 30, 2026 at 06:45 AM · View previous versions
Approximately, how old is the battery? There should be a date stamp on it. And, is this really a genuine Sony NP-FZ 100? My understanding is, there are fake batteries, parading as genuine...
Yes, genuine, the one that came with the camera originally. So 2019 if not older. Don't really see a date stamp, just some random numbers
EDIT: It says 20180717WBA, so 2018 I guess?
Edited on Mar 30, 2026 at 06:45 AM · View previous versions
Mar 29, 2026 at 10:43 AM
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p.1 #11Sony a9 battery leak
Did the plastic melt or does it look as if it were softened by chemicals? Li-ion batteries can get very hot, maybe your camera saved you from a fire.
Mar 29, 2026 at 11:18 AM
p.1 #12Sony a9 battery leak
Altglas wrote:
Did the plastic melt or does it look as if it were softened by chemicals? Li-ion batteries can get very hot, maybe your camera saved you from a fire.
Hard to tell, but probably softened by chemicals - there was still liquid under the arca-swiss plate when I took it off.
Did the plastic melt or does it look as if it were softened by chemicals? Li-ion batteries can get very hot, maybe your camera saved you from a fire.
Hard to tell, but probably softened by chemicals - there was still liquid under the arca-swiss plate when I took it off.
Mar 29, 2026 at 11:26 AM
p.1 #13Sony a9 battery leak
A battery that was over seven years old failed. This is very annoying, especially considering the consequences for the camera, but these things happen. Technology, especially when it comes to consumable parts, breaks down. I don't understand what kind of reaction you expect from the manufacturer. And even if the defect was caused by the camera, the warranty expired many years ago. As I said, I understand the frustration, but things happen.
Mar 29, 2026 at 11:41 AM
p.1 #14Sony a9 battery leak
Nifty Fifty wrote:
A battery that was over seven years old failed. This is very annoying, especially considering the consequences for the camera, but these things happen. Technology, especially when it comes to consumable parts, breaks down. I don't understand what kind of reaction you expect from the manufacturer. And even if the defect was caused by the camera, the warranty expired many years ago. As I said, I understand the frustration, but things happen.
That's certainly a way to look at it.
My view is different - in a camera marketed as a professional tool, the battery should not fail in such a way that the camera is destroyed. Not in 7 years, not in 10.
Sure, things happen, but I haven't had any li-ion battery fail in any of my devices in such a destructive way. I don't think it should.
I expect the manufacturer to repair or replace the camera - now whether or not it will happen, we shall see.
A battery that was over seven years old failed. This is very annoying, especially considering the consequences for the camera, but these things happen. Technology, especially when it comes to consumable parts, breaks down. I don't understand what kind of reaction you expect from the manufacturer. And even if the defect was caused by the camera, the warranty expired many years ago. As I said, I understand the frustration, but things happen.
That's certainly a way to look at it.
My view is different - in a camera marketed as a professional tool, the battery should not fail in such a way that the camera is destroyed. Not in 7 years, not in 10.
Sure, things happen, but I haven't had any li-ion battery fail in any of my devices in such a destructive way. I don't think it should.
I expect the manufacturer to repair or replace the camera - now whether or not it will happen, we shall see.
Mar 29, 2026 at 06:36 PM
p.1 #15Sony a9 battery leak
I doubt your expectations will be met.
I'd be feeling lucky it did not burn your house down.
I'd be feeling lucky it did not burn your house down.
Mar 29, 2026 at 07:08 PM
p.1 #16Sony a9 battery leak
My oldest NP-FZ100 were from 2017 and they worked fine 5.5 years from mfg. date compared with overlaid disharge curves of new batteries. I've not seen any leaks with INR cells in camera battery packs or any other application. The metal cylindrical cells are hermetically sealed. Leakage must be rare or serious failures can occur, unlike alkaline cells that commonly leak.
It's probably worth contacting Sony about it, since leaks should not happen.
EBH
It's probably worth contacting Sony about it, since leaks should not happen.
EBH
Mar 29, 2026 at 10:47 PM
p.1 #17Sony a9 battery leak
mt-m wrote:
Hard to tell, but probably softened by chemicals - there was still liquid under the arca-swiss plate when I took it off.
Melting is thermal and dissolving is chemical. Did you send the camera in for service?
EBH
Altglas wrote
Did the plastic melt or does it look as if it were softened by chemicals? Li-ion batteries can get very hot, maybe your camera saved you from a fire.Melting is thermal and dissolving is chemical. Did you send the camera in for service?
EBH
Mar 29, 2026 at 10:49 PM
p.1 #18Sony a9 battery leak
mt-m wrote:
That's certainly a way to look at it.
That's not a way to look at it; it reflects the legal situation.
mt-m wrote:
I expect the manufacturer to repair or replace the camera - now whether or not it will happen, we shall see.
One can expect a lot, and who knows, maybe you'll get lucky and the person handling your request will have a good day and, as a gesture of goodwill on Sony's behalf, will accommodate you.
But how you arrive at such an expectation is still a mystery to me. As far as I know, no camera manufacturer offers a free lifetime warranty on "professional equipment."
Anyone who wants to be protected against all possible defects has the option of insuring their equipment as they see fit. There are many possibilities. But of course, it's not free.
That's certainly a way to look at it.
That's not a way to look at it; it reflects the legal situation.
mt-m wrote:
I expect the manufacturer to repair or replace the camera - now whether or not it will happen, we shall see.
One can expect a lot, and who knows, maybe you'll get lucky and the person handling your request will have a good day and, as a gesture of goodwill on Sony's behalf, will accommodate you.
But how you arrive at such an expectation is still a mystery to me. As far as I know, no camera manufacturer offers a free lifetime warranty on "professional equipment."
Anyone who wants to be protected against all possible defects has the option of insuring their equipment as they see fit. There are many possibilities. But of course, it's not free.
Mar 30, 2026 at 02:35 AM
p.1 #19Sony a9 battery leak
FZ100 is a very good battery but eventually it will age just as all other batteries. I think this discussion is a good reminder for us all.
Edited on Mar 30, 2026 at 07:05 AM · View previous versions
Edited on Mar 30, 2026 at 07:05 AM · View previous versions
Mar 30, 2026 at 05:26 AM
p.1 #20Sony a9 battery leak
EB-1 wrote:
My oldest NP-FZ100 were from 2017.
My original A7RVI battery is also marked as 2017; almost 10 years now...
Thankfully I don't use my camera every day, but this thread sure got me a bit paranoid. The battery sure is something I'll keep an eye out for from now on.
My oldest NP-FZ100 were from 2017.
My original A7RVI battery is also marked as 2017; almost 10 years now...
Thankfully I don't use my camera every day, but this thread sure got me a bit paranoid. The battery sure is something I'll keep an eye out for from now on.
Mar 30, 2026 at 05:35 AM