... you'll never find an aircraft or sub with soldered connections.

Of course, Dads Truck isn't going to fall out of the sky or sink to the bottom of the ocean...

 

I hope not.

But, setting aside the question of soldering, what about a solenoid with which to parallel batteries? How much current capability does it need? This is for the boat and the alternator appears to be capable of 60 amps, so the bigger load might be one battery charging the other after running the stereo for a while when stopped.

 

I think you want an isolator, not a relay.

 

My understanding of isolators is that most are solid-state devices and, because of that, have a voltage drop across them. Typically that is up to .7v, which results in the battery or batteries never getting fully charged. But, do I have that wrong?

 

Isolators usually are covering a house deep cycle battery.
.7V from 14.35 is still 13.65V.... and that's charging in my mind.

 

my advice is to buy the battery cables!

 

You are correct in that there will be a voltage drop across a diode style isolator and it is really nothing that your alternator cannot compensate for if hooked up correctly. Problem is you must sense your voltage output after the isolator and if you are charging 2 batteries, well you must pick one and hope for the best on the second one. Any sort of solenoid, (and wiring) must be capable of handling the full output of the alternator. For example, a 100A alternator could easily overtax an 85A rated solenoid, even though normal charging current would be far below that. Just a bit of worst case planning. Now, assuming the second battery will only power non vehicle operating equipment, such as an RV hookup, you could run a lesser rated solenoid for charging purposes only, but would fuse the circuit at the rating for the solenoid to protect it. A blown fuse is easier to deal with than a fire.

 

... and a 130A 3G that can easily put out 160 if the belt doesn't slip?

That's a hell of a continious rated relay.

Check; Texas Industrial Electric

http://www.texasindustrialelectric.com/battery_isolators.asp

 

I really need to get one of those crimpers too, as I have some cables to replace also. The only bad thing I've heard about them is the sizing is off a bit. Start big if you're not positive which size die to use as you can always go down a size.

Those battery terminals are awesome! I've used them before and love 'em. Not sure if you know, they are sized for positive and negative terminals and can not be switched, so get them in sets.

I also really need to get away from soldering terminals too. When you solder, the flux creeps up the wire under the insulation, slowly ruining the wires over time (think our factory type connectors that turn green and stop working over time). That is the main reason I am buying the expensive automotive crimp-type terminals now, and use adhesive-lined heat shrink on all exterior connections.

 

You use rosin flux on electrical connections.
Pine pitch isn't going to attack the copper.

(Why do I feel I shouldn't be encouraging this?)

 

I dont know where the best place to get cable is anymore/ I used to get it at this place called Great Lakes Skipper. However, they dont seem to have anywhere near the selection they used to. I would be interested myself if someone has a great site. I looked at DelCity and they had some stuff.

 

Flag Battery Terminals (Automotive Post)

This place looks good

 

Wow. Paused to see Star Wars, in 3D no less, and got 8 responses. Thanks, guys!

Matt - Buying battery cables isn't happening as it doesn't require a new tool. Seriously though, there's no way I could get the cables just the way I want them w/o making them. And, as said, I have at least 5 sets of cables that need to be made, which easily justifies a $45 tool.

And, speaking of the tool, I'm wavering on which one to get. Here's my thinking:

• 10 Ton unit
  10 Ton unit
  : According to what I've read, this one has die that will crimp from 10 gauge to 2/0. This seems to be just the right range for me as I can't imagine needing anything larger than 2/0, and certainly have done a lot of 10 gauge stuff in the past. So, this is now my plan.
• 16 Ton unit
  16 Ton unit
  : I thought this one was what I wanted, but then I realized that it does from #6 to HUGE - way beyond 4/0. So, since I can't see crimping anything that big, I'm leaning to the other one. However, what are the odds those
  crimp-style battery terminals
  crimp-style battery terminals
  have a barrel bigger than 2/0?

As for the battery isolator vs solenoid thing, this is for my boat and, as I said, it has a 60 amp alternator. So, even the 85 amp solenoid would be adequate for the alternator's output. But, my question was how much current I might expect when one battery has been pulled down quite a bit and the other is fresh. Will 85 amps of capacity be enough, or do I need the 200 amp unit?

And, I'm aware I could modify the sensing of my charging system, but I don't want to do that. So, I'll either use a solenoid or a battery isolator. But, as I think about it, I've made things too simple in my mind. I have two batteries, a Perko battery selector switch that can choose none, 1, 2, or 1 & 2, and an on/off battery switch. And I have the engine to power as well as a significant stereo system. So, it is going to take some thinking to figure out how best to use this "stuff" in an efficient manner.

81ChopTop - The undersized issue appears to come from the Harbor Freight 10 ton crimper. Luke shared a link in Dad's Truck thread to a web site where that problem was cussed and discussed over 7 pages. So, today I held one of their crimpers in my hands and discovered that their die are now labeled in AWG, but it tops out at 1/0 instead of the 2/0 that I'm assured the 10 ton unit above will do. So, for $55+tax I put it back on the shelf and will order one from Amazon.

Brandon - Thanks for the link. I'll follow up.

 

Followed up on the link Bruno gave, and there's a section on battery isolators. In that section there are instructions for marine battery isolators, and here's an excerpt from them:As it turns out, my boat has a Chevy engine w/a single-wire Delco alternator. Guess I'll call Sure Power tomorrow.

 

Did you look at my link to TIE?

You can browse from that isolator page to their relays and the rest of their products.