Perko switch question (1 engine 2 battery)

Nextelbuddy

Petty Officer 2nd Class
Joined
May 4, 2020
Messages
156
So I wanted to install a second battery with a perko switch.

I purchased a second battery, battery tray, two new 24-in battery cables, One new 24-in ground cable, and the perco switch

All three new cables have the 3/8 lug ends.

Well I want to go install today and on my current installation the wire that goes from my starter to my battery is a 2 gauge And when it terminates at my battery it uses a ring terminal.

My understanding I'm supposed to take that wire off the battery and attach to the common post on the perko switch but the perko switch uses a 3/8 lug stud.

So what am I supposed to do? Cut off the ring terminal and attach a two gauge 3/8 lug end what am I supposed to run a completely new 2 gauge wire that's 3/8 lug on both ends?


The starter wire that goes from the starter to the battery is a 0 or 2 gauge (I can't tell) wire but the two new 24-in power wires I got are 4 gauge

I figure since it's only about 12 from the perko switch to the battery itself that running 4 gauge wire should be okay.

My main thing is just trying to figure out what to do about the ring terminal end.

If I have to replace the ring terminal end with a 3/8 lug it's not a crimp connection I assume it has to be tinned/soldered to be proper?

PXL_20210905_184530081.jpg
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,757
Best to have ring terminals on Bat cables on a boat. Terminals should be crimped and then sealed. No soldering because if cable gets hot it could melt the solder and pull out

Below uses an ACRTwo Bat one switch and ACR.jpg
 

Nextelbuddy

Petty Officer 2nd Class
Joined
May 4, 2020
Messages
156
Best to have ring terminals on Bat cables on a boat. Terminals should be crimped and then sealed. No soldering because if cable gets hot it could melt the solder and pull out

Below uses an ACRView attachment 349179
I I think my terminology is incorrect. When I said ring terminal I meant the large clamp terminal you see in the picture... Just like on a car or a truck battery my boat has a large clamp terminal on the battery post and that wire goes to the starter.

So I'm trying to figure out what other people are doing when they use a perko switch.

Every YouTube video I see nobody ever talks about this they all just install the switch and good to go.

So I'm curious if my battery terminal wire from the starter to the battery has an incorrect terminal clamp? Or if that's normal and I'm supposed to replace that terminal clamp with the standard 3/8 ring terminal instead?

The perko switch that I have has three posts on the back for common one and two and they all use a 3/8 post with a nut So obviously I can't attach the large terminal clamp from my starter wire to the common post like that.

Just find it so hard to believe that of all the videos and DIYs that I'm looking online nobody ever says oh by the way you need to remove your terminal clamp and install a standard 3/8 ring terminal...
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,757
Yes I understood what you had when replying

Someone replaced the cables with incorrect ones and this is the reason no one on you tube talks about them
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,503
So I'm curious if my battery terminal wire from the starter to the battery has an incorrect terminal clamp? Or if that's normal and I'm supposed to replace that terminal clamp with the standard 3/8 ring terminal instead?

The perko switch that I have has three posts on the back for common one and two and they all use a 3/8 post with a nut So obviously I can't attach the large terminal clamp from my starter wire to the common post like that.

Just find it so hard to believe that of all the videos and DIYs that I'm looking online nobody ever says oh by the way you need to remove your terminal clamp and install a standard 3/8 ring terminal...
You do not use automotive style battery clamps on a boat for a number of reasons.

While we are at it, what is with all the cables connected to the battery?

Should be one cable between battery and switch. Some tie bilge pump wire to battery as well. Otherwise, accessory connections acc terminal on switch
 

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
Yep, and that automotive battery cable is most likely not of the marine variety, so it should probably be completely changed anyway.
Marine wire is tinned throughout it's entire length.

You can buy a custom cable with the ends already terminated. There are online sites that will make it up for you.
Or you can buy the cable, crimps, heat shrink, crimper and do it yourself.
 
Top