Two Stupid Battery / Connector Questions

[Ward H]

1. My OB neg terminal connector is one size too small for my busbar. Busbar is 3/8, connector is 5/16. I see two options. Drill the connector bigger or install a fuse block terminal with 5/16 stud. OK to just drill it?

2. Studs on battery have wing nuts. OK to just change over to SS hex nuts?

 

[Stu Jackson]

If you drill it out, it'll have less surface area. Not a great idea. Easy fix though, ain't it? Either pull the wire and put the correct lug on it, or do a splice somehow, as you suggest.

Wing nuts are now a no-no. While I don't agree with it with proper lock washers, get some nylocks and do it right.

Good luck.

 

[Joe]

Wing nuts are now a no-no.
Good luck.

????

 

[JK_Boston_Catalina310]

????

Wing nuts can loosen due to vibration and cause all kinds of problems. Use hex nuts or lock nuts if you know what you are doing.

 

[Stu Jackson]

????

Joe, Maine Sail has mentioned this many, many times.

While I personally disagree with it, since wing nuts are not different with split lock washers, he & ABYC recommend using nylocks. I have never had any issues with wing nuts in 35 years, but what the heck...

 

[Ron20324]

...While I personally disagree with it, since wing nuts are not different with split lock washers, he & ABYC recommend using nylocks. I have never had any issues with wing nuts in 35 years, but what the heck...

+1

 

[Benny17441]

Oh, for all these years I have not known what I was doing! I'm still using wing nuts and have never had a problem. I do know the importance of a tight connection to prevent arching and check my batteries and connections regularly.

 

[mitiempo]

Problem is it is hard to tighten a wing nut enough, unless you have a wing nut wrench. Most I see are not tight enough.

 

[seadaddler]

Wing Nuts

I did change my wing nuts to hex nuts but be careful not to strip
them on the battery lugs and have had wing nuts and just use adjustable wrench always works.

 

[slaume]

If you need to use a wrench to tighten them, what is the point of using wing nuts?

 

[Ward H]

The light bulb came on while driving to work this morning.
Batteries have one size stud for + terminal (3/8") and another size for - terminal (5/16").
I should have used a busbar with 5/16" post for the negative connections. Easily fixed, parts ordered.

As to the wing nuts, that is easily fixed also. Stu gave the info I needed. I will use nylocks.

Thanks

 

[JK_Boston_Catalina310]

The light bulb came on while driving to work this morning.
Batteries have one size stud for + terminal (3/8") and another size for - terminal (5/16").
I should have used a busbar with 5/16" post for the negative connections. Easily fixed, parts ordered.

As to the wing nuts, that is easily fixed also. Stu gave the info I needed. I will use nylocks.

Thanks

Read this link if you plan to use nylocks. http://www.pbase.com/mainecruising/battery_meltdown_averted

Back to your above post, I haven't seen batteries that have different size terminals. The only place I have 3/8" on my system is the shunt for the battery monitor. Everything else is 5/16". If you have a 3/8" buss bar, is this new or something existing?

 

[Stu Jackson]

jk, thanks, I was completely WRONG.

I stand or sit corrected.

 

[Joe]

Joe, Maine Sail has mentioned this many, many times.

While I personally disagree with it, since wing nuts are not different with split lock washers, he & ABYC recommend using nylocks. I have never had any issues with wing nuts in 35 years, but what the heck...

Thank you stu.... at least you didn't infer I don't know what I'm doing like JK did... I guess I read that before but I've never had a problem with it on my boat... 'course I don't feel much vibration from my outboard.

I will probably NOT rush down and change the nuts.... but perhaps, casually pick some up while shopping for other things. heh, heh.

I did change my wing nuts to hex nuts but be careful not to strip
them on the battery lugs and have had wing nuts and just use adjustable wrench always works.

So.... I guess I should "torque" them... what setting is recommended.

 

[JK_Boston_Catalina310]

Thank you stu.... at least you didn't infer I don't know what I'm doing like JK did...

Sorry man, that was an accident. I was responding on my phone while laying in bed and typed too quick.

Also, to be clear I meant that you should only use nylocks if you know what you are doing and that you have to be sure to torque them correctly or you can create other problems.

I apologize if I offended you or gave the impression that you didn't know what you were doing.

Jesse

 

[mitiempo]

... I haven't seen batteries that have different size terminals. The only place I have 3/8" on my system is the shunt for the battery monitor. Everything else is 5/16". If you have a 3/8" buss bar, is this new or something existing?

4D and 8D batteries usually have 3/8" positive and 5/16" negative posts. Group 24, 27, and 31 usually have 5/16" for both posts. Many Agm batteries have 1/4" for both posts.

 

[Stu Jackson]

I just bought new batteries, US 310s. 3/8 and 5/16. Who says the old days are gone?

 

[mitiempo]

It does vary. I am going by the batteries we sell.

Golf carts are 5/16" for both posts also.

 

[Ward H]

JK,
I did make a couple of assumptions since i did not actually measure the threaded post on the battery. Here are the points I considered.
1. I seem to remember that on car batteries the positive post was larger than negative post. Its been awhile since I have changed a battery. Could be wrong.
2. Blue Sea Fuse Block Terminals have 3/8 hole for battery terminal. 5/16 post for fuse and ring terminal. Lit says 5/16 or 3/8 ring terminal can be used. Since positive side is only side to be fused assumed positive post was 3/8.
3. Blue Sea Power Buss Bar with two posts only available with 3/8 posts. Assumed this was for positive connections.
4. Blue Sea Power Connector for extending outboard electric cable has 3/8 post w/red cover and 5/16 post w/black cover. Leads me to believe OB positive ring is 3/8 and neg ring is 5/16. Found this out this morning.
5. Marina connected outboard directly to battery last year. No bat switch in place.
6. I added BS mSeries bat switch, which has 3/8 posts. Also added two power bus bars with two 3/8 posts. Bat positive cable runs from bat fuse block terminal to switch, then to buss bar 1. Neg cable runs from bat to buss bar 2. Have not connected bat yet.
Outboard positive cable ring terminal fits 3/8 buss bar. Outboard neg cable ring terminal does not fit 3/8 post on buss bar. Must be 5/16.
All this has led me to believe the battery threaded positive post is 3/8 and neg post is 5/16.

I plan on putting a fuse block terminal on neg buss bar 2 so i have a 5/16 post to connect OB neg cable to. I will not use a fuse. If that does not work i will change cable terminal size to 3/8.

And after reading the link to Maine's comments on nylocks i think i will go with hex nut and lock washer. Thanks for the link.

My main question was would it be OK to drll out the under sized terminal. Sounds like no so i will change what is needed to make proper connections.

Thanks

 

[Ron20324]

Drill it out. No need for the hassle and expense. The O.D. may well be the same for both sizes, just different holes, so no advantage to chg lugs.