Voltage drop

Pilar · 11-04-2009, 11:01 PM

I'm working on a boat and solving a problem for another salty dog. I won't mention his name. Anyway the symptoms are unreliable starting, charging problems, electrical part failure (relays) and a few other things not related.

This boat has twin cat diesels and is pretty big. Nice boat BTW, especially for as old as it is.

I noticed right away that there was a pretty big voltage drop when the engine electrical power was switched on. Starboard side was much worse than port but both engines. After a day of tracing wiring and cleaning up rotten ring terminals and corroded connections I moved on. Mainly because nothing I repaired really changed the voltage drop. It dropped from 13.5 volts to 10.2 on the starboard side and down to 12.3 on the port. 10% is the max acceptable for anything other than electronics which is 1 to 2%. Something was eating up the power needed to operate the engine controls and instruments.

I opened the battery box and

found this

Not right away of course but it was pretty obvious when I tried to break apart the worst looking terminal.

As near as I can tell what happened was the connection was loose and heat under high current load built up and melted the starboard (+) battery terminal. The starboard engine would still start if you cross connected the 2 batteries but the charging indications were erratic. It would not start at all on it's own battery.

The puddle of lead did not damage the case other than looks. Actually the "post" is formed with an acetelyne torch, a post mold and a 1/4" square stick of lead like giant solder at the battery factory. The case lid has extra thick plastic to withstand this heat.

Corrosion makes high resistance connections. This causes heat build up and a voltage drop which may prevent starting or make your electronics drop out when you crank it up. Bad grounds can cause things to work only some of the time or not at all. Any of this main power wiring on starters, battery isolators or battery terminals that is discolored (dark, heat) or green or white (corrosion) may cause you grief. This is a good time of year to look at your power wiring, clean it up if needed and tighten any loose connections.

For a limited amount of protection you can spray on a cosmoline type spray like LPS 3 or the Boeing boe spray. Coat the assembled connections and when dry coat again. This stuff makes a waxy coating that will repel moisture and help prevent the green stuff from growing.

It took a little while to pull the cables off the starters and the batteries and clean it all up. I replaced the 4 battery terminals with new ones. They only last a few years before the stuff starts to rot. This totally fixed the problems or most of them anyway. I also sealed the cable ends with heat shrink and liquid tape. Here's the rest of the 'before' pictures. More tomorrow of the 'after'.

PapaHog · 11-04-2009, 11:12 PM

That does look ugly. Hope it fixes the problems. Look forward to tomorrows pictures.

Good Job.

MattPark · 11-04-2009, 11:44 PM

That's some serious corrosion/damage, and a great reminder for the rest of us.

Hoghunter · 11-05-2009, 05:45 AM

Those batteries were obviously neglected for a long time.

Keta · 11-05-2009, 06:36 AM

Yuck!

Bluefinn · 11-05-2009, 06:36 AM

Great post John.Thanks

Wet Fly · 11-05-2009, 06:43 AM

Speaking of Batteries is there a product that will disconnect the battery if the voltage drops below a certain range. I have a set up that I need something like this so if I forget to turn off the system it would do it for me.

Nice post John.

HOGGEMIN · 11-05-2009, 07:40 AM

Great post John keep them comming...............

:applaus e:

Seefood Man · 11-05-2009, 10:01 AM

That is pretty bad. I have seen where the battery cables themselves have corroded on the inside of the insulation, without having any visible indication of a problem.

Teton · 11-05-2009, 11:57 AM

Great work John.

Now, if we could just figure out the other problem...but hey, that's what the offseason is for. Working on equipment.

Megabites · 11-05-2009, 12:49 PM

I've seen this before. In that case the connection was lose not dirty. Check and make sure your connections are tight as well as clean. Then seal them as Pilar mentioned.

On a more scary note that connection most likly arced as well. Any fuel fumes and your boat becomes a terrorist weapon. This should be on the "I check every year list" at a minimum.

ripnlips1 · 11-05-2009, 12:55 PM

Quote:

Originally Posted by Megabites

I've seen this before. In that case the connection was lose not dirty. Check and make sure your connections are tight as well as clean. Then seal them as Pilar mentioned.

On a more scary note that connection most likly arced as well. Any fuel fumes and your boat becomes a terrorist weapon. This should be on the "I check every year list" at a minimum.

It's a diesel boat. Diesel fumes don't ignite but a gas powered boat would.

Pilar · 11-05-2009, 02:16 PM

Yep twin diesel. That's how you get enough heat to melt the terminal. The starter is almost as big around as a coffee can. So there is some amp draw when you crank it.

The dirty connections, loose connections, corroded connections thing is kind of a circle.

Robin, I think you might find some kind of battery charging/protection relay that will do that. You just have to connect a big contactor to break the circuit.

HOGGEMIN · 11-05-2009, 03:16 PM

Looks much better John. Nice clean connections now, nice work.

fyshndad · 11-05-2009, 03:31 PM

Nice job John
Thanks for sharing
It is timely indeed

fishin"G"man · 11-05-2009, 03:44 PM

Perhaps unrelated but have you looked for issues with electrolysis/ power cord polarity issues and the like? What do zincs, fastners etc look like if that much corrosion is on the battery?

Corrosion begins with an unexpected problem every time. Just a thought provoking suggestion... look at the dock wiring or perhaps boats around you. Are they having similar issues?

Woody · 11-05-2009, 03:57 PM

Atta boy John!

s20055 · 11-05-2009, 04:17 PM

Load test the battery as well. You might have some bad cells, which means cleaning won't be enough. You'll need to replace the batteries.

tracker · 11-05-2009, 05:40 PM

Good thing to be checking! Thanks John!

tomictime · 11-05-2009, 06:22 PM

tinned lug on connectors
bond and ground relies on 5 factors:
clean
similar metals
no corossion
surface area, only 1% cold welded really carries the load
torque

Onokai · 11-06-2009, 08:55 AM

One little thing that also helps after cleaning it all up is current conducting grease -I use a product called De-OX made by Ilsco good for aluminum and copper conections
Mark

Keta · 11-06-2009, 09:03 AM

Quote:

Originally Posted by ripnlips1

It's a diesel boat. Diesel fumes don't ignite but a gas powered boat would.

Uh..... If diesel fumes are between the LEL and the UEL (LEL %: 0.3 / UEL %; 10.0) it WILL ignite with bad consequences. Diesel is a far safer fuel than gas though.

Here's a MSDS for diesel.

http://www.petrocard.com/Products/MSDS-ULS.pdf

"Unusual Fire & Explosion Hazards:

This material is flammable and can be ignited by heat, sparks, flames, or other sources of ignition (e.g., static electricity, pilot lights, or mechanical/electrical equipment, and electronic devices such as cell phones, computers, calculators, and pagers which have not been certified as intrinsically safe). Vapors may travel considerable distances to a source of ignition where they can ignite, flash back, or explode. May create vapor/air explosion hazard indoors, in confined spaces, outdoors, or in sewers. Vapors are heavier than air and can accumulate in low areas. If container is not properly cooled, it can rupture in the heat of a fire."

Critr Gitr · 11-07-2009, 11:07 PM

Nice work John ... nothing helps one's confidence on the blue like a solid clean electrical system...

Billfisher · 11-09-2009, 09:16 PM

Quote:

Originally Posted by Critr Gitr

Nice work John ... nothing helps one's confidence on the blue like a solid clean electrical system...

A-MEN!

Cliff D. · 11-11-2009, 11:02 AM

The Johnson Control days have served you well. Good find.

flapbreaker · 11-11-2009, 11:49 AM

I spray all my electrical connections with Corrosion X. It works fabulous at preventing rust ect.. I even sprayed it on nuts and bolts on the trolling motor. Works great.

big fishy · 11-11-2009, 12:40 PM

Thanks Keta for pointing out the "Diesel Thingy". I was a Fire-fighter for 28yrs and I ALWAYS had a job.

		Fish the difference!
IFish Mortgage Special!	THE SALTY DOG SPONSORS!	IFish Investment Advisory Services

11-04-2009, 11:01 PM	#1
Pilar Mr. Carkington Join Date: Aug 2000 Location: Not all that wander are lost. Posts: 10,035	Voltage drop I'm working on a boat and solving a problem for another salty dog. I won't mention his name. Anyway the symptoms are unreliable starting, charging problems, electrical part failure (relays) and a few other things not related. This boat has twin cat diesels and is pretty big. Nice boat BTW, especially for as old as it is. I noticed right away that there was a pretty big voltage drop when the engine electrical power was switched on. Starboard side was much worse than port but both engines. After a day of tracing wiring and cleaning up rotten ring terminals and corroded connections I moved on. Mainly because nothing I repaired really changed the voltage drop. It dropped from 13.5 volts to 10.2 on the starboard side and down to 12.3 on the port. 10% is the max acceptable for anything other than electronics which is 1 to 2%. Something was eating up the power needed to operate the engine controls and instruments. I opened the battery box and found this Not right away of course but it was pretty obvious when I tried to break apart the worst looking terminal. As near as I can tell what happened was the connection was loose and heat under high current load built up and melted the starboard (+) battery terminal. The starboard engine would still start if you cross connected the 2 batteries but the charging indications were erratic. It would not start at all on it's own battery. The puddle of lead did not damage the case other than looks. Actually the "post" is formed with an acetelyne torch, a post mold and a 1/4" square stick of lead like giant solder at the battery factory. The case lid has extra thick plastic to withstand this heat. Corrosion makes high resistance connections. This causes heat build up and a voltage drop which may prevent starting or make your electronics drop out when you crank it up. Bad grounds can cause things to work only some of the time or not at all. Any of this main power wiring on starters, battery isolators or battery terminals that is discolored (dark, heat) or green or white (corrosion) may cause you grief. This is a good time of year to look at your power wiring, clean it up if needed and tighten any loose connections. For a limited amount of protection you can spray on a cosmoline type spray like LPS 3 or the Boeing boe spray. Coat the assembled connections and when dry coat again. This stuff makes a waxy coating that will repel moisture and help prevent the green stuff from growing. It took a little while to pull the cables off the starters and the batteries and clean it all up. I replaced the 4 battery terminals with new ones. They only last a few years before the stuff starts to rot. This totally fixed the problems or most of them anyway. I also sealed the cable ends with heat shrink and liquid tape. Here's the rest of the 'before' pictures. More tomorrow of the 'after'. __________________ Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart; the centre cannot hold; Last edited by Pilar; 11-04-2009 at 11:07 PM.

11-04-2009, 11:12 PM	#2
PapaHog Super Moderator Join Date: Apr 2002 Location: Canby Oregon Posts: 20,823	Re: Voltage drop That does look ugly. Hope it fixes the problems. Look forward to tomorrows pictures. Good Job. __________________ Ken papahog Lane ifish Christmas party December 1, 2009 Pietro's Pizza Restaurant 10300 SE Main Milwaukie 503.659.7770 5 to 8 (ish) pm

11-04-2009, 11:44 PM	#3
MattPark Ifish Nate Join Date: Sep 2005 Location: Vancouver, WA Posts: 2,799	Re: Voltage drop That's some serious corrosion/damage, and a great reminder for the rest of us.

11-05-2009, 05:45 AM	#4
Hoghunter Chromer Join Date: Oct 2003 Location: Snohomish, WA Posts: 680	Re: Voltage drop Those batteries were obviously neglected for a long time.

11-05-2009, 06:36 AM	#5
Keta Tuna! Join Date: Aug 2009 Location: Klamath Falls...for now Posts: 1,033	Re: Voltage drop Yuck! __________________ Support OCEAN for the future of Oregon saltwater fishing OCEAN Pro Staff, Hogg's Hardcore Tuna Tackle Fred Archer's Bartender Club, Ask me about Archer Super Bars

11-05-2009, 06:36 AM	#6
Bluefinn Ifish Nate Join Date: May 2003 Location: Turner Oregon Posts: 2,303	Re: Voltage drop Great post John.Thanks __________________ May you always have fair skies,calm seas,fair currents,following winds and tight lines. Boat 29' Open Ocean "WILDCAT" slip C-56 Newport. Oregon Coalition for Educating Anglers board member http://www.oceaned.org/

11-05-2009, 06:43 AM	#7
Wet Fly Ifish Nate Join Date: Aug 2002 Location: Or. Posts: 2,214	Re: Voltage drop Speaking of Batteries is there a product that will disconnect the battery if the voltage drops below a certain range. I have a set up that I need something like this so if I forget to turn off the system it would do it for me. Nice post John. __________________ The Lady Irish Now a Tuna Captain Morrage location Newport Boat length 26' North West Custom Boat Works We build custom Boat Arches

11-05-2009, 07:40 AM	#8
HOGGEMIN Sturgeon Join Date: Sep 2002 Location: Gresham Posts: 4,336	Re: Voltage drop Great post John keep them comming...............:applaus e: __________________ Owner of HOGG'S Hardcore Tuna Tackle If its not 200lbs just chunk it, member of the 200lb club Profesional Boat HO Take your kids hunting or fishing so you don't have to hunt for your kids. Team EAT ME lures

11-05-2009, 10:01 AM	#9
Seefood Man Ifish Nate Join Date: Nov 2001 Location: Woodland Posts: 2,991	Re: Voltage drop That is pretty bad. I have seen where the battery cables themselves have corroded on the inside of the insulation, without having any visible indication of a problem.

11-05-2009, 11:57 AM	#10
Teton Ifish Nate Join Date: Nov 2005 Posts: 3,356	Re: Voltage drop Great work John. Now, if we could just figure out the other problem...but hey, that's what the offseason is for. Working on equipment. __________________

11-05-2009, 12:49 PM	#11
Megabites Tuna! Join Date: Apr 2002 Location: Aurora, OR Posts: 1,060	Re: Voltage drop I've seen this before. In that case the connection was lose not dirty. Check and make sure your connections are tight as well as clean. Then seal them as Pilar mentioned. On a more scary note that connection most likly arced as well. Any fuel fumes and your boat becomes a terrorist weapon. This should be on the "I check every year list" at a minimum. __________________ You know your a redneck if you think megabytes is a good day fishing.

11-05-2009, 02:16 PM	#13
Pilar Mr. Carkington Join Date: Aug 2000 Location: Not all that wander are lost. Posts: 10,035	Re: Voltage drop Yep twin diesel. That's how you get enough heat to melt the terminal. The starter is almost as big around as a coffee can. So there is some amp draw when you crank it. The dirty connections, loose connections, corroded connections thing is kind of a circle. Robin, I think you might find some kind of battery charging/protection relay that will do that. You just have to connect a big contactor to break the circuit. __________________ Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart; the centre cannot hold;

11-05-2009, 03:16 PM	#14
HOGGEMIN Sturgeon Join Date: Sep 2002 Location: Gresham Posts: 4,336	Re: Voltage drop Looks much better John. Nice clean connections now, nice work. __________________ Owner of HOGG'S Hardcore Tuna Tackle If its not 200lbs just chunk it, member of the 200lb club Profesional Boat HO Take your kids hunting or fishing so you don't have to hunt for your kids. Team EAT ME lures

11-05-2009, 03:31 PM	#15
fyshndad King Salmon Join Date: Jul 2006 Location: Milwaukie OR Posts: 5,209	Re: Voltage drop Nice job John Thanks for sharing It is timely indeed __________________ Hank Capt' 07 OTC Team "MEMORIES" Depoe Bay/Newport Team member Dances with Tuna Astoria OTC 08 Capt team "MEMORIES" REPORT GAME VIOLATIONS WA 1800 477 6224 OR 1800 452 7888 Sleep is for people that don't know how to fish! Making "MEMORIES" one day at a time Member CCA, NWSteelheaders,

11-05-2009, 03:44 PM	#16
fishin"G"man Steelhead Join Date: Jun 2009 Location: Long Beach, WA Posts: 147	Re: Voltage drop Perhaps unrelated but have you looked for issues with electrolysis/ power cord polarity issues and the like? What do zincs, fastners etc look like if that much corrosion is on the battery? Corrosion begins with an unexpected problem every time. Just a thought provoking suggestion... look at the dock wiring or perhaps boats around you. Are they having similar issues?

11-05-2009, 03:57 PM	#17
Woody Ifish Nate Join Date: Mar 2003 Posts: 3,423	Re: Voltage drop Atta boy John! __________________ "How inappropriate to call this planet Earth when it is quite clearly Ocean." Sir Arthur C. Clarke DTR Woodcraft is now an Ifish sponsor. Contact me for all your custom woodworking needs. If it's wood, I can build it. Have an idea? Lets talk!

11-05-2009, 04:17 PM	#18
s20055 Steelhead Join Date: Jul 2007 Location: Oregon City Posts: 396	Re: Voltage drop Load test the battery as well. You might have some bad cells, which means cleaning won't be enough. You'll need to replace the batteries. __________________ "They say you forget your troubles on a trout stream or an elk trail, but that's not quite it. What happens is that you begin to see where your troubles fit into the grand scheme of things, and suddenly they're just not such a big deal anymore."

11-05-2009, 05:40 PM	#19
tracker King Salmon Join Date: Jul 2004 Location: Graham Wa Posts: 5,123	Re: Voltage drop Good thing to be checking! Thanks John! __________________ Third 2008 OTC Garibaldi event! OTC participant 2005-2009 Third overall combined weight-2009! Only participant to fish all OTC events!

11-05-2009, 06:22 PM	#20
tomictime Ifish Nate Join Date: Dec 2004 Posts: 2,971	Re: Voltage drop tinned lug on connectors bond and ground relies on 5 factors: clean similar metals no corossion surface area, only 1% cold welded really carries the load torque

11-06-2009, 08:55 AM	#21
Onokai Ifish Nate Join Date: Jul 2003 Location: Arcata Posts: 2,783	Re: Voltage drop One little thing that also helps after cleaning it all up is current conducting grease -I use a product called De-OX made by Ilsco good for aluminum and copper conections Mark __________________ ONOKAI ...................... TUNA is a STATE of MIND

11-07-2009, 11:07 PM	#23
Critr Gitr Tuna! Join Date: May 2003 Location: Veneta (The Gateway to Elmira) West of The Peoples Republic of Eugene Posts: 1,228	Re: Voltage drop Nice work John ... nothing helps one's confidence on the blue like a solid clean electrical system... __________________ <')))< “The mountains, the forest, and the sea, render men savage; they develop the fierce, but yet do not destroy the human.” ~~ Victor Hugo Team

11-11-2009, 11:02 AM	#25
Cliff D. Tuna! Join Date: Jan 2006 Location: Colton Posts: 1,277	Re: Voltage drop The Johnson Control days have served you well. Good find.

11-11-2009, 11:49 AM	#26
flapbreaker Ifish Nate Join Date: Jul 2004 Location: Hillsboro, OR Posts: 3,232	Re: Voltage drop I spray all my electrical connections with Corrosion X. It works fabulous at preventing rust ect.. I even sprayed it on nuts and bolts on the trolling motor. Works great.

11-11-2009, 12:40 PM	#27
big fishy Steelhead Join Date: Jul 2003 Location: Boise, ID Posts: 241	Re: Voltage drop Thanks Keta for pointing out the "Diesel Thingy". I was a Fire-fighter for 28yrs and I ALWAYS had a job. __________________ BiG FiShY

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode