What causes battery crusties

[Blmpkn]

Do the AGM batteries do better? I know they have tighter voltage requirements and may get killed on older vehicles, but they seem more sealed.

Unrelated story but somewhat same subject: My dad had a Navy story of sacrificial anodes on the ships. They replaced them on a ship, but plugged them in backwards so the ship became the sacrificial part. It sat in port for a couple days before they noticed. That ship had to be scrapped and the ship next to it had to be taken to dry dock for critical repair.

Yeesh. How big of a ship? If that's not one of the most expensive mistakes ever made I don't know what would be lol.

 

[Curious Hound]

As written, that's a strange story. Sacrificial anodes are usually chunks of zinc bolted to the steel structure of the ship. Pretty hard to hook them up backwards. Must be a misunderstanding somewhere.

 

[Chapap]

His ship was something like 250 or 300 feet. Not big enough to actually be an ocean going ship. I think the anodes are supposed to be negative and the salt water is positive, and somehow the zinc corrodes first amd protects the iron hull. This was some kind of system that was hooked to a power source of some kind that was supposed to give them a negative charge. Instead, they got a positive charge which ruined everything. I suppose it’s possible that they were a storage system that’s only used in port. It does seem like a tall order to charge a piece of metal that’s welded to the ship without charging the ship too.

 

[Curious Hound]

Ship's electrical systems can be tricky for this very reason.

 

[Chapap]

Correction. It wasn’t sacrificial anodes. It was impressed current cathodic protection (ICCP).

 

[fixizin]

On a related note, the only difference between electric (tanked) water heaters with the 6-Year warranties, and the "premium" ones with 12-Year warranties, is the former have only 1 sacrificial anode, and the latter have 2!... you can add your own and save a lot of $$.

 

[Dirtman]

Sacrificial anodes only work when suspended in an electrolyte solution, aka salt water or mineral (hard) water. My water heater doesn't even have one cause I have neutral PH water with nothing in it so it wouldn't do anything anyway. (I've had people tell me my water tastes bad, I say no that's just how pure water tastes lol). The ones on my boat don't have power to them, the difference in metal creates the charge, that's how the anodes work. I dunno about big ships but that's the basis of a battery, suspend two different metals in a electrolyte solution and a charge is created, give that solution something to run through better besides the good parts and it'll attack that and run power through that first aka the sacrificial anode.

Navy ships work different because they actually put out a charge to demagnetize the entire hull. (Philadelphia experiment) thought this was cloaking technology but it's basic anti mine technology. So who knows how sacrificial anodes work on those things.

 

[RonD]

Ships like Seaview and Enterprise put electrical charge on hulls to prevent creatures from crushing them or sucking them dry