Battery Isolator

[Ramiro0727]

I have a 69 Chevy C10. I added a accuair air ride system. I'm going with a dual battery setup. The batteries are behind the cab mounted on the frame. I'm trying where is a good place to mount the battery isolator. To keep it from.getting wet. If I mount it on the frame as well. Trying to keep the battery cables from.the isolator to the batteries short. Anyone have any ideas.

Thanks,
Ramiro

[PbFut]

Manual or electronic switch? Isolating what? Charging system, or suspension motors.
If you want to isolate the aux batteries from truck, you may want to wire like a oem aux rv battery. I am not familiar with these systems. When do you need to isolate? With a bit of planning you should be able to use a high amp relay or solenoid to do what you need electrically. My RV battery mimics OE option and only connects to the truck system in run position. Battery is isolated in all other states. Protects truck battery from draining while camping. Also isolates during start protecting from back feed and popping the fuse link

[Orange Crate]

I have had this one under the hood in my other 4X4 (dual battery sys) for probably 15 years. Never had any issues, it just works. Check out their site, they have a couple of different options with wiring diagrams.

https://www.hellroaring.com/bic95150B.php

[Ramiro0727]

Originally Posted by PbFut

Manual or electronic switch? Isolating what? Charging system, or suspension motors.
If you want to isolate the aux batteries from truck, you may want to wire like a oem aux rv battery. I am not familiar with these systems. When do you need to isolate? With a bit of planning you should be able to use a high amp relay or solenoid to do what you need electrically. My RV battery mimics OE option and only connects to the truck system in run position. Battery is isolated in all other states. Protects truck battery from draining while camping. Also isolates during start protecting from back feed and popping the fuse link

PBFut for the charging system. It's a manual switch I believe. It's a Stinger Isolator.

Ramiro

[mr48chev]

A lot of motor homes just use a continuous duty solenoid as the battery isolator for the coach batteries.

The ones I worked had the trigger wire wired through the ignition switch with a toggle switch in between so they could only be engaged when the key was in the run position. The toggle switch was so you didn't have to charge them if you didn't want to. A good Cole -Herse solenoid runs between 30 and 40 dollars depending on where you buy it.

[PbFut]

This is my idea with full disclosure, I have zero employment field experience on this subject. To me, it is a simple use case as follows.
1 Aux Batteries need connection to truck system solely to charge.
2 Batteries will provide very high amp service for short term to bag motors.
3 best practice would be to isolate aux batteries from truck system in off, start, and suspension adjustment periods to prevent back feed and high amp forward feed to protect charge curcuit.
This can be accomplished with a 1 high amp and 1 low amp standard relay as follows.
1 set up your bag system as normal to the aux batteries.
2 use a normally open high amp relay switching a fuse link or fuse protected line from truck system to positive aux battery terminal. A 10 or 8 guage wire is plenty capable. I like fuse links and are easy to learn how they work. Control the relay with a run only source.
Here's the important part. Add a standard relay in the control line. Use a normally closed relay. This allows the high amp relay to work only in the run position. Connect the control line of this second relay to the air bag system power running the motors This will interrupt the control lead to the high amp relay, isolating the batteries while you are running the bag motors.
Doing this second relay protects the truck system and charging line if the aux batteries are low and the motors try to pull high amp power from the truck.
I hope this all makes sense. Wiring in this manner will completely eliminate any manual switching of the charge curcuit.

[PbFut]

I think these will work
High amp.
True Mods 12V DC 120 Amp Split Charge Relay Switch - 4 Terminal Relays for Truck Boat Marine https://a.co/d/2dCPbbS
Low amp but still very high for this use can use much lower without issue
ZAHUO123 Car Universal Transparent Relay 12V 5 Foot 80A Car Waterproof with Indicator Light Relay for Car Modification Special Relay Durable（2Pcs) https://a.co/d/5nht1yK

[Ramiro0727]

Originally Posted by PbFut

I think these will work
High amp.
True Mods 12V DC 120 Amp Split Charge Relay Switch - 4 Terminal Relays for Truck Boat Marine https://a.co/d/2dCPbbS
Low amp but still very high for this use can use much lower without issue
ZAHUO123 Car Universal Transparent Relay 12V 5 Foot 80A Car Waterproof with Indicator Light Relay for Car Modification Special Relay Durable（2Pcs) https://a.co/d/5nht1yK

PbFut, Thank you.

[PbFut]

One other thing came to mind. This whole thing is to prevent back feeds between batteries. One thing I failed to do on the RV battery while working on my truck the other day. I needed to kill all voltage to the truck system for safety. I left the key in run position on accident, so RV battery relay was closed and RV battery was electrically connected to the truck system. Lazy me disconnected the neg line to truck battery. There were no accessories on, and it disconnected quick, so no alerting arc. Given the positive and neg line of the RV battery was still connected and the key was in run position, the RV battery back fed into the truck system and kept the hi amp relay trigger energized even though I had disconnected the truck battery and engine was off. So Truck battery was manually isolated but the RV battery was back feeding hot to the truck 8 gauge jump line and powering the truck system as if the truck battery was connected.
It is fuse linked so nothing would of fried had I arced a line, but it could have been an issue. So lesson learned. When working on the truck with a multi battery system, ALWAYS manually disconnect ALL batteries. Either all positive or all negative lines at the battery.

[Orange Crate]

Originally Posted by PbFut

One other thing came to mind. This whole thing is to prevent back feeds between batteries. One thing I failed to do on the RV battery while working on my truck the other day. I needed to kill all voltage to the truck system for safety. I left the key in run position on accident, so RV battery relay was closed and RV battery was electrically connected to the truck system. Lazy me disconnected the neg line to truck battery. There were no accessories on, and it disconnected quick, so no alerting arc. Given the positive and neg line of the RV battery was still connected and the key was in run position, the RV battery back fed into the truck system and kept the hi amp relay trigger energized even though I had disconnected the truck battery and engine was off. So Truck battery was manually isolated but the RV battery was back feeding hot to the truck 8 gauge jump line and powering the truck system as if the truck battery was connected.
It is fuse linked so nothing would of fried had I arced a line, but it could have been an issue. So lesson learned. When working on the truck with a multi battery system, ALWAYS manually disconnect ALL batteries. Either all positive or all negative lines at the battery.

All of this is taken care of with a good isolator. The one I linked to above has an optional manual switch so you can connect the second battery if the vehicle is not running or you can connect them before starting/winching ect...

[PbFut]

Originally Posted by Orange Crate

All of this is taken care of with a good isolator. The one I linked to above has an optional manual switch so you can connect the second battery if the vehicle is not running or you can connect them before starting/winching ect...

Yes, 100% agree the linked isolator will do the job. I struggle with the $200+ price tag given 2 relays for under 20 bucks will do the same thing. The device looks good with the heat sinks and all, but if there is overheat issues I would question if the device is correctly sized to begin with. This connection should not be heating up to a point of needing heat fins. This device looks to me to be nothing more than 2 high amp relays in a fancy box.

[Orange Crate]

Originally Posted by PbFut

Yes, 100% agree the linked isolator will do the job. I struggle with the $200+ price tag given 2 relays for under 20 bucks will do the same thing. The device looks good with the heat sinks and all, but if there is overheat issues I would question if the device is correctly sized to begin with. This connection should not be heating up to a point of needing heat fins. This device looks to me to be nothing more than 2 high amp relays in a fancy box.

Wow, you have no idea how good that isolator is and you are completely wrong about its engineering and performance. Maybe you missed that I've had one for 15 years working perfectly with no issues. I have a winch and "house" battery in that system. There are other really good isolators out there also. Could you please start a new thread in 15 years with your update on the relays.

[PbFut]

Not saying the isolator is not a good product. I am saying two relays, one high amp, one low amp, will do the same as the $200+ isolator device for 1/10 the cost. It also would not surprise me that these relays will last 15 years. The ones in my TBSS lasted 12 before I sold it and likely still clicking away. I think the isolator is a really cool product but I can swap out the relays 9 times and still be money ahead. It just occurred to me this may be your product you are selling. Apologies if I come across as dising the device. For many I am sure it is the perfect device. For me, i tend lean twords shade tree solutions since the bank account struggles to afford much more than a treehouse..

[Killer Bee]

late to the game but I'll throw in my two pfennigs

I manage a 9,400 unit utility company fleet, we have battery isolators in just about everything larger than a sedan

We replace solid state battery isolators probably 100:1 over solenoid types

I remember as a supervisor some lasting barely 1-2 years in a few trucks, along with a set of batteries usually

in fact, in many cases we replace the solid state with a solenoid when feasible because they're more reliable and last longer

sure power (like the stinger mentioned above) are the most popular solenoids with our techs

like I said, we replace the 140a and 200a diode cole hersees (installed by the body upfitters) by the dozens

now that's full time high use fleet experience, low personal use or recreational use may work differently

but as mr48chev mentioned above, my motorhome has a sure power in it

ymmv and good luck with your project!