Hearing the liquid inside battery when shaking?

Just curious - battery noob here. I had one battery fail on me, and when I tried shaking it around I could hear the liquid inside swishing around like I was shaking a bottle of water. It's a non-rechargeable D-sized LiSOCl2 cell for reference.

Could anyone explain to me what happened here? I understand primary lithium cells have electrolyte fluid inside them, but what could be the reason something like this happens? Is it a manufacturing error? Is it totally harmless? I have dozens of similar batteries and none of them have this issue.

SOCl2 is thionyl chloride - the liquid cathode adsorbed onto carbon..

Not very nice stuff.

I'm surprised you can hear anything slopping about in the cell - but you did say it was faulty..

Don't cut it open.


Really really don't let the contents leak out, it releases sulfur dioxide and hydrochloric acid when exposed to
moisture, meaning the fumes are extremely corrosive to flesh, can damage lung tissue rapidly. And it forms an
explosive mix with air or oxygen. In chemistry labs this stuff is only ever handled in a fume-hood.

If you suspect it is faulty do not leave it indoors or anywhere it could be a hazard if it catastrophically leaks,
ie take outside - perhaps put under brine like LiPo's are?

Thionyl chloride cells are specialist due to combination of very long life and high current capabilities (used for
burglar alarms I believe) I'd avoid using them if you can.

Thanks, I have enough common sense not to cut any batteries open. I know what LiSOCl2s usually are used for (very low self-discharge, high capacity) which is exactly why I'm using them for the device I'm building.

This is a new batch of batteries from a different vendor I usually buy them from - I only have about 4 of them, and in fact 2 of them now are showing this issue - it just feels like I'm shaking a bottle of water. The 20 or so other ones I have have it to a small extent - you can definitely feel something moving inside if you shake it hard enough, but it's not as noticeable.

I'm just wondering to what extent this is considered normal in a battery, and if this can be considered to be any signage of a faulty battery....the other one still works.

The chemistry of the battery utilizes liquid SOCl2 and gaseous SO2. What you are hearing is bubbles of sulfur dioxide churning around with the liquid thionyl chloride. I would recommend that you not shake them, and you won't hear a thing.