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LTX and LSXPutting LT1s, LS1s, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects including repairs, swap info, and performance upgrades.
When it comes to where to put the battery, the members of this forum have options. Put it on the driver's side? On the passenger side? Totally abandon the engine compartment and put it in the back of the car? Yeah. Options. Options bring decisions, which brings research, which is why this thread exists.
For those of you who made the decision to keep it in the engine compartment, what influenced your decision? Factory placement probably weighs in heavily here, so I want to hear from those of you who got past that small bit of inertia. Let's see some good reasons for one side or the other, along with some awesome pictures of your engine bays
Battery can be treated as weight ballast so put it wherever the corner weights tell you.
And then there's the real world....
I left mine in the engine bay because it was easy. It seemed routing main power distribution is easier from driver side, but routing starter cables is easier from passenger side. So the deciding factor for me was where the air filter needed to go. I preferred air filter placement on passenger side, so battery stayed in stock location (Firebird) on driver side. It was reasons of practicality.
The huge turn off for me of ever doing a rear battery mount is you'll never be able to go to a track without a battery disconnect switch poking out the back of your car. I am not putting those tacky devices through my tail light or bumper. I've done a lot of things to my car but messing up the body is not one of them.
The primary reason for moving the battery to the rear was the ABS and air cleaner box in the front battery trays (see above picture). Since I redesigned the entire electrical system for the car, I decided to mount the battery in the “trunk”, centered because of the IRS, if a live axle is used, then you can mount it in the spare tire well. The starter circuit and full length ground circuit run along the right side and the power distribution/charging circuits are on the left side. The rear mount battery is also a convenient location for the “hot” fuel pump wiring. Moving the weight to the rear was just an added benefit, but not the primary reason for this modification. This is a street car, with an occasional open track day, so I do not need to have a cut off switch. Which begs the question, why is a cut off switch “required” for a rear mount battery, but not for a traditional front mount battery? Why are they not required for an OEM rear mount battery?
I like to get as much junk out of our Engine-Compartments as possible...
Getting our Engine-Compartments to look good, takes a ton of work (Deleting, Shaving, Smoothing, Etc).
Unless someone competes in a class where use of a Remote Battery Disconnect is required...
The Battery always goes in the back!
I like to get as much junk out of our Engine-Compartments as possible...
Getting our Engine-Compartments to look good, takes a ton of work (Deleting, Shaving, Smoothing, Etc).
Unless someone competes in a class where use of a Remote Battery Disconnect is required...
The Battery always goes in the back!
I prefer this as well. I did install a cutoff switch and although my current one is ugly, there are a few coated billet ones out there that will blend in better. With the camaro taillights you can cut into the inner shroud piece. I can always do away with the switch and get a new shroud cover. My biggest reason for adding the cut off swtich was for safely disconnecting all power when adding custom circuits and such to the car. It saved me from a fire early on in my wiring adventures.
I prefer this as well. I did install a cutoff switch and although my current one is ugly, there are a few coated billet ones out there that will blend in better. With the camaro taillights you can cut into the inner shroud piece. I can always do away with the switch and get a new shroud cover. My biggest reason for adding the cut off swtich was for safely disconnecting all power when adding custom circuits and such to the car. It saved me from a fire early on in my wiring adventures.
exactly exactly. I love having the ability to park the car and flip the switch and have all the electronics be dead. if I am doing work on the car, or welding, or just want the power off, its a flip of the switch. My battery is in the back also, for the performance purposes, weight distribution, and mostly because it allowed me to really clean up the engine bay. it was a hassle (and a bit of added weight) to run all the heavy 1-gauge power/ground cables back there, but everything has worked just fine and I am glad I have it this way. I have a distribution block and a jump-post up where the battery used to be.
edit:
better photo showing what the area looks like with no battery.
Last edited by IROCZman15; 06-12-2022 at 06:42 PM.
Gota move it to the back to make up for the weight of a turbo in the front
I recommend if you move it to the back, run separate ground and power wires to the engine block, not just chassis grounds.
I put a 150amp fuse right off the battery primary wire so if anything happens like an accident crushing the 1/0 feed wont weld and start a fire.
Another thing I do is use terminals which can be easily kicked off or knocked off in the event of an emergency, don't use powerful terminals that are going to heat up and turn molten red then attached so strongly you can't pry them off with your bare hands quickly or easily.
What I like about the back is the power lead to fuel pump and relay is extremely short.
The annoying part is running those huge long wires somewhere safe inside the cabin. I wrapped my power wire completely in a giant fuel hose, surrounded that with convoluted tube and around that some bubble wrap and additional leather sheath. Where it goes through the firewall use a bulkhead style connector not a regular grommet.
Its super annoying but if you ground properly, protect it, fuse it, and use terminals that remove easily, it can be made quite safe and effective.
The Images below will show one of my favorite Rear-Mounted Battery Power-Distribution Connections...
This works well for a 0/ 2/ 4AWG Cable being split into Three-Branches (8AWG or so) that can be Locked with CPAs or completely disconnected quickly:
Further down the line, individual Connections can be made:
Each of the 3 Branches have a maximum continuous Ampacity of 60A, which supports Power-Distribution Systems up to a combined 180A.
If Higher Amperage Branches are required, the next size up is for 125A:
Last edited by vorteciroc; 06-07-2022 at 07:35 PM.
instead of fuses, i like to use those large weatherproof circuit breakers that you can simply click-to-reset. yes fuses are cheap, but then you have to keep spares around and whatnot. This style breaker does the same job , and you can open it (cut power) if you needed to work on the car....just the same as if you removed a fuse.
Another amazing example of cleaning-up the Engine-Compartment!
Would you PM me some Images, or direct me to some Images of the Engine-Compartment, as well as the work that you did.
So many different members here have completed similar processes; Its fun to find new/ different ways people work towards similar goals!
Another amazing example of cleaning-up the Engine-Compartment!
Would you PM me some Images, or direct me to some Images of the Engine-Compartment, as well as the work that you did.
So many different members here have completed similar processes; Its fun to find new/ different ways people work towards similar goals!
sure thing, will send the Pm to you in a few minutes. I do need to get better engine bay pictures out in the sunlight; that photo I just walked out to the garage and snapped it with a flashlight and the iphone. I'll get some better ones soon, but I will send you a PM to my build thread(s), so we can keep the OP's topic on topic.
Those engine bay pics have been nice guys! I figured some of the "move it to the back!" crowd would be first up
I'm a bit surprised nobody has chimed in about one side in the engine bay being easier vs. the other for the air intake given clearance with the radiator hoses. I'm inclined to put the battery back where the factory put it (driver's side on the Pontiacs like mine). I'll need to figure out how best to run the starter cable again as what was left of the plastic piece along the bottom of the radiator is long gone which held it before.
I'm a bit surprised nobody has chimed in about one side in the engine bay being easier vs. the other for the air intake given clearance with the radiator hoses.
Another option is to leave it in engine bay and use a lightweight battery. They got those now and it's popular with the C5/C6 Corvette crowd. Kind of checks all the boxes for weight reduction and simplicity, but it ain't cheap and I think cold start performance suffers (pretty much a warm season battery).
I'll tell you what, those lithium starting batteries are some sensitive stuff though and I've witnessed one fail during life cycle testing. Heard a pop and wooosh! noise through thick blast window, then flames shooting 4 foot straight out the side, followed by smoke filling a room about the size of a small house in seconds. Personally, I'll pass.
I'll tell you what, those lithium starting batteries are some sensitive stuff though and I've witnessed one fail during life cycle testing. Heard a pop and wooosh! noise through thick blast window, then flames shooting 4 foot straight out the side, followed by smoke filling a room about the size of a small house in seconds. Personally, I'll pass.
Yes, Thermal Runaway. This has happened with aircraft and electric cars. It's been well documented, and I also will pass.
There is a company called Mighty Maxx , they make sealed lead acid battery,
I got a couple to play with 5 years ago, it says 35AH on the side which is nothing and this little battery only weighs maybe 28lbs, its 8.5x6x7" and this little thing cranks over my 5.3L V8 faster than the huge typical lead acid battery that we are used to seeing. I tested it's resting voltage is still 13.25v after a month of sitting un-used, as opposed to 12.65 typical lead acid battery will supply fully charged.
It's around $55 shipped and I am so impressed for the price.
I bought an even smaller one for like $33 shipped and I keep it as a battery jump box, literally turn it upside down with a short 6" cable for ground to jump start peoples dead battery, stuck anywhere. I also put a very tiny one as a normal battery into a corolla and its just been perfect. I mean, an almost laptop sized battery runs the car.
Well actually capacitors are quite leaky and it would drain the battery quickly if there was a cap inside, you can't just leave a cap charging its constantly losing energy
Also if you charge a cap at 12.65v the maximum a cap can charge to is 12.649999v it can never charge to supply rail fully due to the leaking
If you want to take say 3v or 12v and turn it into 15v or 200,000v that takes some doing. Either an oscillator with transformer type of deal or some creativity involving diodes and transistors. I used to play around with stun gun circuits here are some voltage increasing circuits
I also used to make my own fireworks, mortars, flash powder, every color lance... but some things no matter how interesting and pretty are dangerous enough that eventually it chips your tooth or stops your heart. I won't mess with it again until I am better equipped for safety...
Well actually capacitors are quite leaky and it would drain the battery quickly if there was a cap inside, you can't just leave a cap charging its constantly losing energy
Also if you charge a cap at 12.65v the maximum a cap can charge to is 12.649999v it can never charge to supply rail fully due to the leaking
No, often times the super cap will have an isolation switch that preserves the charge after engine shut down so it's at 14V or whatever the alternator was charging. Not all are that way but the better units are. Super caps used with starting systems actually have extremely good leak down rates and hold high charge for many months. But yes, units without the isolator will be at battery voltage.
I never tried it or used it before, we don't get the cool stuff at school
Symmetrical EC’s, supercapacitors, or ultracapacitors, are powerful devices but have shortcomings when used for engine starting or high pulse-power applications. The shortcomings of a symmetrical design include a high self-discharge rate, the need for voltage balancing between the cells, the type(s) of electrolyte, and the methodology used to enclose each of the cells.
I guess days is possible from the nickle version?
Thats amazing if its truly a cap. I see 13.25v after a couple months I think. idk whats inside but they are good
It says supercapacitors will "Modules will leak down to 0 volts quickly. Must be “re-charged” prior to use, causing un-due stress on the batteries in the circuit."
But the KApower nickle carbon "Will not “drain” batteries if left in a parallel connection" so its not a supercapacitor exactly?
The reason caps scare me is their rapid discharge rate can be deadly. In a vehicle where we come into contact with the battery and charging circuits I don't think such a design is wise. I just don't know the safety issue there.
And being a cap I don't see how it could charge above supply rail voltage anyways.
I think the cells inside are just higher voltage than typical lead acid is all. I think the starting power is just from higher resting voltage.
Moved mine to back when i went turbo so i had room for the snail and piping. Ultimately i dont think it matters for most applications. You either need the room or you dont. And for a serious fast drag car, it becomes ballast in a sense. Put it where its needed. We all put them in the back to get weight off the nose…then some become so fast on a radial, we actually need more front bias in weight to keep nose down. Sometimes you want it on the rear for no prep or street traction.
It seemed routing main power distribution is easier from driver side, but routing starter cables is easier from passenger side. So the deciding factor for me was where the air filter needed to go. I preferred air filter placement on passenger side, so battery stayed in stock location (Firebird) on driver side. It was reasons of practicality.
I agree on the electrical distribution advantages for one side vs. the other. Why did you prefer the air filter placement on the passenger side?
Why did you prefer the air filter placement on the passenger side?
Driver side is congested. More room on passenger side and better line of sight. More room for filter. More room under the tray if you want to pass thru. And there's more cool air source from fender on passenger side too.
I had one of those you build it kits and just started mocking up stuff and situating in the engine bay. No planning needed, just hands-on with some parts and a miter saw.
I considered moving it.... Kept it in the engine because
1. Easy access
2. That's a lot of cable to run to the trunk
3. It works fine as is
4. need to make a vent system in the back. Also, inevitable spills / battery acid in the back / passenger compartment.
5. Itd take up trunk space.
6. Possibly scratching up the palstics / trim when removing / installing
7. Routing that cable under the car... lots of potential for it hitting / rubbing things / corrosion / damage
If you do not carry the Mini Spare Tire ( for example, I do not, as it will not fit over the larger Brakes that I installed)...
You can mount the Battery in the Spare Tire Compartment.
Fab a Mount and retaining Bracket for the battery.
...and keep 2 Cans of Tire Sealant/ Inflator in your Car in addition to your Fire Extinguisher and Tool Case.
06-05-2022, 10:57 AM
