Battery terminal - What is this?

[john61ct]

Batteries are consumables, if more than 3-4 years starts like that just replace it.

 

[Padeen]

Dielectric grease is an insulator. If you dress a battery connection with dielectric grease, I assume it is only applied after the connection is made up?

 

[john61ct]

Only the silicone-based type, and a very thin coat, gets gummed up over time.

Really the spray is better.

And not gassing too much, plus not having a leak.

 

[FF]

"This is happening because you are overcharging the battery.
Get a better charger. Do not put charging voltage on a battery that is fully charged or you will get corrosion."

This is a good possibility, dock side a dumb charger may go to full charge before switching back to float.

This could happen with every operation of the FW pump , bilge pump, reefer operation , or even just lights.

Solar is also a suspect as most go to top voltage then drop to float.

On an unused boat this can easily cause overcharging.

In the "old days" folks installed converters ,( very poor as chargers) to reduce the battery overcharging and the need for watering.

Solar and some modern chargers can be adjusted , to keep the boil down.

 

[Art]

IMO - Don't charge batteries till they need it [especially good condition ones - the only type I keep on our boat]. How many cars and trucks have you had where soon as you stopped using it for relatively short period of time [couple weeks and even up to six months or longer] you felt need to immediately put their battery on "float charge". Yes, batts will slowly discharge on their own... but unless they have an actual draw on their energy their cranking power will last at least somewhat in tact for months at a time with no charging necessary. When engine is started the batts are soon fully recharged. If I'm to leave a batt idle for very long period I check it with multi meter occasionally [every two to three months]. When it hits 12.3 I place a full charge back into the battery by one means or another and the cycle of "let the battery alone for prolonged period" starts all over. Goes without saying that the batt must be isolated with no draw on its energy whatsoever.


In other words... all the float this and float that BS about constantly keeping batts up on full charge is unnecessary [unless you have some sort of constant energy draw]. And charging-equipment failure or mal adjustment can really create havoc with batteries and even a fire if things get too far out of whack.


Due to our family life conditions and 99.8 mile distance to our boat's dock... We too often need to leave our boat sit idle for up to three months. I leave all the batteries at 100% charge [12.7 on multi meter]. By turning off the Perko switches they sit isolated with absolutely no draw on their energy. When we return, even after two to three months, the batts register 12.4 to 12.5. So... as we ready to leave the slip for a long weekend of play on the water, I turn on the charger using shore power. Soon as heck the batts are back to 100% and we hook up our tow behind Crestliner runabout for going out to have repeat days of fun times on the boat.


I believe in and practice - KISS!

 

[john61ct]

But deep-cycle batteries on cruising boats are online with variable constant loads sometimes large ones. This makes it hard for normal charge sources to guess their SoC based on circuit voltages.

If an expensive bank, best to put them behind an AH -counting batt monitor and let its intelligence control charge sources.

This is more critical with cruising sailboats, stinkpots get away with a lot less since alts mostly running all the time.

 

[sdowney717]

For DC power usage, I worry about those unexpected events where bilge pumps need to run, and that will drain down batteries unless they are being charged. I have 6 DC Rule bilge pumps, and on several different circuit breakers.

 

[Art]

For DC power usage, I worry about those unexpected events where bilge pumps need to run, and that will drain down batteries unless they are being charged. I have 6 DC Rule bilge pumps, and on several different circuit breakers.

Repeat need for bilge pumps while away from boat is a worry for sure...

However, I believe that worry should be mitigated against worry for other calamities that may happen due to incessantly charging batteries. Such as fire due to charger failure/short - Battery over heating and/or melting/exploding - Improper wire gauge that heats too much and has its casing melt creating a hazard - fire from shore power hookup... I do not know the stats regarding what % of sinking occurs from unattended leaking raw water as compared to fire from electrical items on a boat; batteries and chargers and shore lines specifically. I'd imagine that unattended leaking is more often the cause. But don't forget... just because a boat sinks at dock does not mean it was a "leak" of raw water per say... heavy rain is also a culprit.

Anyway - I believe that by Keeping my boat hulls and thru hulls in good condition as well as that not keeping my boat electrically hooked to shore power and therefore having no battery charger running while I'm away give me best chance for continued battery life and floating boat having no complications.

Don't forget - Insurance company pays for replenishment or replacement of sunken boats... but not for replacement of ruined batteries or fried chargers... that I know of!

All in all... boats are a some what of a worry regarding always keeping them floating. It is my feeling that as long as I keep all thru-hulls well sealed and in good condition and make sure other potential raw-water intrusion locations are in a leak proof state that my boat will sit fine on its bottom in the water without need for charging batteries.

Happy Boat-Float Daze! - Art

 

[dhays]

Dielectric grease is an insulator. If you dress a battery connection with dielectric grease, I assume it is only applied after the connection is made up?

I use it before the connection is assembled. The grease simply displaces air in the space between the connectors. Where the two connectors touch, there is no grease and you have a good connection. Besides keeping water away from the connections, the grease helps eliminate air gaps that can cause sparking and heat.

At least that is my own simple understanding. As with many things, I could easily be wrong.

 

[sdowney717]

Repeat need for bilge pumps while away from boat is a worry for sure...

However, I believe that worry should be mitigated against worry for other calamities that may happen due to incessantly charging batteries. Such as fire due to charger failure/short - Battery over heating and/or melting/exploding - Improper wire gauge that heats too much and has its casing melt creating a hazard - fire from shore power hookup... I do not know the stats regarding what % of sinking occurs from unattended leaking raw water as compared to fire from electrical items on a boat; batteries and chargers and shore lines specifically. I'd imagine that unattended leaking is more often the cause. But don't forget... just because a boat sinks at dock does not mean it was a "leak" of raw water per say... heavy rain is also a culprit.

Anyway - I believe that by Keeping my boat hulls and thru hulls in good condition as well as that not keeping my boat electrically hooked to shore power and therefore having no battery charger running while I'm away give me best chance for continued battery life and floating boat having no complications.

Don't forget - Insurance company pays for replenishment or replacement of sunken boats... but not for replacement of ruined batteries or fried chargers... that I know of!

All in all... boats are a some what of a worry regarding always keeping them floating. It is my feeling that as long as I keep all thru-hulls well sealed and in good condition and make sure other potential raw-water intrusion locations are in a leak proof state that my boat will sit fine on its bottom in the water without need for charging batteries.

Happy Boat-Float Daze! - Art

Guy I knew had a steel sailboat docked in deep water marina at Fort Monroe, Hampton VA. A rubber hose too big in diameter popped off a thru hull when the single clamp broke. Boat sank in the slip down 12 feet. Cost him $12,000 to raise it and tow it to another marina where he then gave up his dream of sailing round the world (I think). He went back to working as an electrician to raise funds, but his boat now is sitting on the hard at Marina Cove Boat Basin in Hampton Va for at least 5 years now.

He was skimpy on his batteries and his pumps.

 

[dhays]

He was skimpy on his batteries and his pumps.

Lose his dream over the lack of a second SS clamp.

 

[Mako]

He was skimpy on his batteries and his pumps.

A hundred batteries and pumps wouldn't have saved his boat... it was doomed.

But look at the good side... at least it didn't happen at sea.

 

[HopCar]

I use it before the connection is assembled. The grease simply displaces air in the space between the connectors. Where the two connectors touch, there is no grease and you have a good connection. Besides keeping water away from the connections, the grease helps eliminate air gaps that can cause sparking and heat.

At least that is my own simple understanding. As with many things, I could easily be wrong.

Exactly right. The grease squeezes out where there is metal to metal contact. If there is room for the grease between the metal surfaces, you don't have contact anyway.

 

[Art]

Exactly right. The grease squeezes out where there is metal to metal contact. If there is room for the grease between the metal surfaces, you don't have contact anyway.

I've found that felt pads under battery clamp with red coating liberally sprayed onto posts, clamp and felt works for years in a row to keep terminals in good condition.