How to make a cheap isolated dual-battery setup for $50
- Thread starter evldave
- Start date
I'd put the switch under the hood to save the trouble of running a wire into the cab. You're likely going to have the hood open anyways at that point to look at the engine.
Otherwise carry a small piece of jumper wire with some gator clips on the ends to power up the solenoid.
I've used a coin to jumper solenoids for self-jumping before. But I'm lazy that way. I prefer to keep the vehicle as simple as possible instead of planning ahead for the worst case scenario since its likely to happen ONCE and not on a regular basis.
Fwiw I have a Landcruiser that has auto-off for the headlights so a bad 'starting' battery is somewhat low probability.
The important thing is to be able to self jump. Spending hours of time to be able to do so at the flick of the switch from the drivers seat is a waste IMO. I'd rather take that time to go fishing with my kids
Otherwise carry a small piece of jumper wire with some gator clips on the ends to power up the solenoid.
I've used a coin to jumper solenoids for self-jumping before. But I'm lazy that way. I prefer to keep the vehicle as simple as possible instead of planning ahead for the worst case scenario since its likely to happen ONCE and not on a regular basis.
Fwiw I have a Landcruiser that has auto-off for the headlights so a bad 'starting' battery is somewhat low probability.
The important thing is to be able to self jump. Spending hours of time to be able to do so at the flick of the switch from the drivers seat is a waste IMO. I'd rather take that time to go fishing with my kids
Another option, if you don't want to run the switch (which hopefully you don't have to use very often) is to buy or make a short 'jumper cable' using a couple roach clips and a short piece of 12 gauge wire...just clip it between the aux battery post and the 'engage' post on the solenoid and you are solid (in a pinch, you can also use a wrench, don't ask how I know
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Fresh
New member
Thanks evldave for for posting this. I used this diagram as a guide for installing another battery in my car. So far so good.
Time for another update!!!
Thanks to dwh, we now have fully grounded switches in our cab! Please note that you can't run the switch power off a Duracell battery - that is for illustrational porpoises only!
I caught an error myself - remember to use the same gauge wire for ground that you use for power! I had the diagram with 4GA ground in the 'high-current' circuit...not a great idea! It's been upgraded to 2GA
Making the system modular on the cheap
So, you want to make it so you can quickly disconnect your solar panel? Easy! Use a weatherpack connector!
Get them from our friendly Amazon tribe HERE - you only need a 2-pin connector. Just wire it in between the charge controller and the battery. Then, when you want to disconnect your solar circuit, just unplug the connector! (note: to prevent risk of fire or explosion, disconnect the sun from your circuit before unplugging the weatherpack connector).
Addendum: If you want to leave the charge controller plugged into your battery and just disconnect the panel, you can do this by moving the weatherpack connector between the panel and the controller. See how easy, cheap and flexible this is????
So you went right out and wired up your trailer based on the first diagram and now you are wondering how to disconnect your trailer? Yes, I forgot trailer disconnects!
Easily fixed! Go HERE and buy part number SB50. Then just wire this into your 4GA wire where it shows in the new diagram (the connector is for 6GA, but you can shove the wire into the connector and using the smaller connector is important for...). While you are at it, order a few extra connectors of the same size (we'll need them later on in this thread, trust me
Here's the new diagram!
Changes:
- Added ground for switch and illustrated power source in dash
- Updated ground wire in high-current circuit to 2GA
- Added connectors to both solar and trailer circuits
- Changed main power lines to red to make it easier to see
would this do the same thing?
http://www.princessauto.com/pal/product/8235673/Battery-Accessories/90A-Battery-Isolator
http://www.princessauto.com/pal/product/8235673/Battery-Accessories/90A-Battery-Isolator
4RunAmok
Explorer
No, these devices reduce the amount of charge each battery will receive, keeping them from ever getting a full charge.
Stick with a solenoid.
http://www.princessauto.com/pal/product/1270088/Solenoids/12V-DC-Grounded-Solenoid
this one? Sorry very new to this. slow learner. been reading a ton before posting...some things i just havent been able to get lol.
this one? Sorry very new to this. slow learner. been reading a ton before posting...some things i just havent been able to get lol.
That looks to be a starter solenoid, which means it's only rated for a short-burst of current. What you want is called a constant (or continuous)-duty solenoid...something like this from Amazon (plus it's cheaper).
If you do use a starter solenoid, it may work, but if it fails, you'll likely never know until it's too late - many times they fail in the 'on' position inside the solenoid, which means you will have a full-time connection between both batteries without any external indication of failure. If you run down both batteries in the middle of nowhere, you're stuck
4RunAmok
Explorer
Yup.
That looks to be a starter solenoid, which means it's only rated for a short-burst of current. What you want is called a constant (or continuous)-duty solenoid...something like this from Amazon (plus it's cheaper).
If you do use a starter solenoid, it may work, but if it fails, you'll likely never know until it's too late - many times they fail in the 'on' position inside the solenoid, which means you will have a full-time connection between both batteries without any external indication of failure. If you run down both batteries in the middle of nowhere, you're stuck
sweet thanks!