# Battery dropped overboard **URL:** \ **Category:** Factual Questions\ **Created:** [December 19, 2016, 4:01pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139 "2016-12-19T16:01:35Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Ornery\_Bob](https://avatars.discourse-cdn.com/v4/letter/o/da6949/32.png) [@Ornery\_Bob](https://boards.straightdope.com/u/Ornery_Bob)\ **Post date:** [December 19, 2016, 4:01pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/1 "2016-12-19T16:01:35Z")
A fully charged 12V SLA battery got dropped into seawater. I’m thinking it must have shorted out and might be dead forever. I’ve got it on the charger now - any chance it’s going to be OK and actually hold a charge? ---
**Author:** ![Me\_Billy](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@Me\_Billy](https://boards.straightdope.com/u/Me_Billy)\ **Post date:** [December 19, 2016, 4:59pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/2 "2016-12-19T16:59:36Z")
Salt or sea water does conduct electricity. I don’t know if that would equal a dead short? So how long was it in the water? And those batteries are pretty well sealed, so I doubt any sea water got inside. If you don’t notice any melted plastic, then probably ok - just would have drained the battery. So just charge it and see it if holds a charge again??? (I would recommend doing this outside where it can’t catch anything on fire should anything happen while charging.) ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [December 19, 2016, 5:15pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/3 "2016-12-19T17:15:30Z")
Seawater is conductive but it’s not some kind of liquid copper or anything. It’s not that conductive. It’s not going to act like a dead short. It will drain the battery, so as **Me\_Billy** said, one of the important questions is how long the battery was in the water. Was this a marine battery? Those tend to be deep-discharge batteries which means that they have thicker plates internally. Thicker plates means less surface area, so they don’t put out as much current at peak, but the thicker plates also means that they can be discharged a lot longer. Automobile batteries, in contrast, tend to have thinner plates that give more instantaneous current but can’t supply current for as long. Put it on a charger and see what happens. Worst case, the battery was in the water for too long and discharged to the point where it chemically self-destructed and won’t hold a charge. ---
**Author:** ![Ornery\_Bob](https://avatars.discourse-cdn.com/v4/letter/o/da6949/32.png) [@Ornery\_Bob](https://boards.straightdope.com/u/Ornery_Bob)\ **Post date:** [December 19, 2016, 7:50pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/4 "2016-12-19T19:50:20Z")
Thanks! It was in the water for quite a while before we were able to recover it, so I’ll see what happens. I put it on the charger before I left for work, so I’ll see if it’s alive when I get home. Thanks again! ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [December 20, 2016, 5:07am UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/5 "2016-12-20T05:07:35Z")
So, what happened? Did it explode and destroy the neighborhood? Create a Superfund contamination zone? Charge, but now outputs only 312 V AC? We NEED to know! ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [December 20, 2016, 9:29am UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/6 "2016-12-20T09:29:16Z")
Bob? Bob? **Bob?** ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [December 20, 2016, 12:28pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/7 "2016-12-20T12:28:14Z")
How’d you get it back out of the water, and how did it fall in? ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [December 20, 2016, 1:37pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/8 "2016-12-20T13:37:33Z")
Crap, now I have to join this thread, just so I can learn of the final result of the seawater battery. Did it survive?..is it dead forever?.. Dammit, I want to know! ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [December 20, 2016, 4:31pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/9 "2016-12-20T16:31:49Z")
What’s a SLA battery? Is that like for a Buick, or a Timex? ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [December 20, 2016, 4:37pm UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/10 "2016-12-20T16:37:47Z")
SLA = sealed lead acid ---
**Author:** ![Common\_Tater](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/common_tater/32/13846_2.png) [@Common\_Tater](https://boards.straightdope.com/u/Common_Tater)\ **Post date:** [December 21, 2016, 8:08am UTC](https://boards.straightdope.com/t/battery-dropped-overboard/775139/11 "2016-12-21T08:08:24Z")
My dad served on a US Navy diesel boat (Submarine) in the late 40s, and as I recall him mentioning that seawater and batteries are a very bad thing, as sulfuric acid + seawater, as every schoolboy knows, makes chlorine gas. Not pleasant underwater. The sealed batteries aren’t completely sealed, if a significant amount of seawater made it inside the battery is probably toast. A conductance test would be interesting, load test etc.