Trunk Mount Battery Options - Which Battery Box, Which Battery, finally... Terminals

[vdubn]

Ok, so I am sure that this has been discussed many times, and in my searching, I found some good threads, but none that really talked about using a battery other than a std Ford battery, or the Optima 34/78 dual post battery. I found some talk of an Odyssey style battery, which is smaller, but won't crank our cars for long if needed, so was curious if there were other common sizes that people had decided to run, that they make billet battery boxes for.

As many others, I am moving the battery to the back hatch area, but I will be mounting mine up just behind the passengers side rear fold down seat. Not back right next to the pass side 6x9 speaker, which is what I usually see. I am doing this so that I can keep as much open space for cargo, or my T-tops, and also keep the speaker area clear so that I can actually hear the music when I'm not listening to the symphony under the hood.

So, I found a couple different battery box options; I want to go with a billet design regardless, not a sheet aluminum box, or a plastic box. I even found a billet style through some marine supply places that have a cover over the top that matches their upper deck, to prevent accidental shorting across the top of the terminals... which is a concern.

Here are the box styles I found:

I like this design the best, nice and simple, but would be awesome if it had a lid like the 2nd pic.


Here is a cast aluminum box, with a top plate and a lid:


Both of the above boxes assume a battery style/type. They assume the Optima 34/78 style, and I am ok with the Optima, its a great battery, but at $170 my cost (which is a decent discount over retail), its still expensive to me. I wondered if there weren't some different options of gel style batteries (want to avoid corrosion, degassing, etc.) that others have had good experience with.

Finally... battery terminals. I will be making my own leads, and the plan is to solder the cables to the terminals, as I don't care for the clamp-on style... they are prone to issues. I saw some of these quick disconnect style connectors, which look pretty slick, but they don't seem to have a solder option. Curious if anyone has found any creative quick disconnect terminals that solder to the battery cables?



If not, no biggie, as I will be running 2 gauge wire, and if there aren't any good quick connect options, I will just run these:

[never]

I’m running this setup...not cheap but small and works awesome!

[brianj]

I know you said you don't want a sheet aluminum box, but I'm posting this anyhow. It lets me use a really large Chrysler lead battery (I wanted the weight ) and it sticks 4" above the trunk floor. I'm going to strap the floor up 4", cover it in luan, and fold the original carpet back down. If you don't know these cars, you won't even know it is there.

[BMW Rider]

Go with the Optima Batteries. Good batteries and lots of nice brackets made for them.

[vdubn]

Any links to the box and battery to see what the price is? How is the Cold Cranking Amps?

I’m running this setup...not cheap but small and works awesome!

[vdubn]

Go with the Optima Batteries. Good batteries and lots of nice brackets made for them.

I think that even though these are a bit more than I want to spend, its probably the most realistic option. Just seeing what others are recommending.

[vdubn]

I still think that the aluminum boxes can be a clean install, like yours, I am just hoping for a more minimal footprint. Nice job on your setup.. and you are right, once you raise the deck and cover it, no one will be the wiser.

I know you said you don't want a sheet aluminum box, but I'm posting this anyhow. It lets me use a really large Chrysler lead battery (I wanted the weight ) and it sticks 4" above the trunk floor. I'm going to strap the floor up 4", cover it in luan, and fold the original carpet back down. If you don't know these cars, you won't even know it is there.

[never]

Any links to the box and battery to see what the price is? How is the Cold Cranking Amps?

Link to the manufacturer:

https://www.braillebattery.com/index...atteries/b3121

The bracket is listed as an add on there.

It’s 1380 pulse cranking amps and something around 550-600 cranking amps...not sure what the CCA is rated at though.

You can get it cheaper at Summit or Jegs.

[erratic50]

You need to ensure the battery is well ventilated to the outside or use a fully sealed battery design.

Additional thoughts - personally I would want something as ridgid as a firewall between me and a battery full of acid -- for personal safety reasons. This is coming from someone who used to tear apart multiple identical batteries and rebuild one. Get burned once pretty good and you'll feel the same way, believe me! And it could have been in the eyes or on the face, luckily it was not.

[steam_mill]

I wanted to put my battery in the hatch on my ‘85. Much like you, I didn’t want to block my 6x9 jbl’s and I didn’t want get rid of my bazooka bass tube.

Where would I put my t-tops if I moved my battery?

[erratic50]

I saw someone do some serious tweaking once that just might work. Was complicated so stay with me

1 - Remove entire cat-back and H
2 - Remove back seat
3 - Cut battery box into floor in front of torque box
4 - box out around opening for strength. Frame around box for protection
5 - connect high flow cat to header
6 - connect custom bent exhaust pipe to cat
7 - turn left exhaust 90 degrees and pass under tail section of T5
8 - route both exhaust pipes immediately after cats down the passenger side.
9 - use a straight-through muffler design staggered on passenger side for space
10 - route pipes out the side or ..... (their answer) or identify route to left side above rear axle
11 - route wires along frame and install battery in box
12 - add vent tube out right rear corner of box passing fumes into trans tunnel
13 - fabricate hard tiedown and lid
14 - re-install back seat

Works out well with some of the short height rectangular batteries

My other idea is to stash small batteries into a stacker grid - wire them in parallel to reach required amperage. I think 6 motorcycle batteries in parallel would do it and they would all fit in the drivers side quarter panel behind the quarter trim. Even easier in a coupe.

The idea I haven't played with before is copy the design of the Porsche Cheyanne - battery in box cut into the floor under the drivers seat basically. Crazy like a fox....

[vdubn]

I wanted to put my battery in the hatch on my ‘85. Much like you, I didn’t want to block my 6x9 jbl’s and I didn’t want get rid of my bazooka bass tube.

Where would I put my t-tops if I moved my battery?

That is a great question.... do you have pics of where your T-Tops stow now? I would like to see some pics of how the T-Tops normally are stored under the hatch. Are you still keeping a spare tire in your spare tire well? One thing to do would be to make a new trunk floor, install your sub into the spare opening, and that way you still have your sub without taking up any space in the cargo area. That is probably what I will do, if I decide to run a sub.

[vdubn]

I saw someone do some serious tweaking once that just might work. Was complicated so stay with me

1 - Remove entire cat-back and H
2 - Remove back seat
3 - Cut battery box into floor in front of torque box
4 - box out around opening for strength. Frame around box for protection
5 - connect high flow cat to header
6 - connect custom bent exhaust pipe to cat
7 - turn left exhaust 90 degrees and pass under tail section of T5
8 - route both exhaust pipes immediately after cats down the passenger side.
9 - use a straight-through muffler design staggered on passenger side for space
10 - route pipes out the side or ..... (their answer) or identify route to left side above rear axle
11 - route wires along frame and install battery in box
12 - add vent tube out right rear corner of box passing fumes into trans tunnel
13 - fabricate hard tiedown and lid
14 - re-install back seat

Works out well with some of the short height rectangular batteries

My other idea is to stash small batteries into a stacker grid - wire them in parallel to reach required amperage. I think 6 motorcycle batteries in parallel would do it and they would all fit in the drivers side quarter panel behind the quarter trim. Even easier in a coupe.

The idea I haven't played with before is copy the design of the Porsche Cheyanne - battery in box cut into the floor under the drivers seat basically. Crazy like a fox....

That does seem crazy like a fox

It could be pretty cool, but it seems like a lot of work. My issue with rerouting any exhaust, is that with a Panhard bar, rear sway, and coilovers, there isn't much room for a single tube, much less 2 going down one side.

I agree with you on the battery venting, but that is only with Lead-Acid. For the Optima gel-cell batteries, they shouldn't require any vent to outside the car, right? I think that is the advantage of the gell-cell, unless I misunderstood.

[mikestang63]

You should run at least 1/0 or 0/0 gauge cable. I use the Taylor box and put a 150 amp inline fuse next the the battery.

[steam_mill]

That is a great question.... do you have pics of where your T-Tops stow now? I would like to see some pics of how the T-Tops normally are stored under the hatch. Are you still keeping a spare tire in your spare tire well? One thing to do would be to make a new trunk floor, install your sub into the spare opening, and that way you still have your sub without taking up any space in the cargo area. That is probably what I will do, if I decide to run a sub.

I’ll post some pics next week. Car is in the city.....

I drive my car regularly to the cottage. We are there about 40 weekends per year. I would be paranoid driving without a spare.

[vdubn]

Link to the manufacturer:

https://www.braillebattery.com/index...atteries/b3121

The bracket is listed as an add on there.

It’s 1380 pulse cranking amps and something around 550-600 cranking amps...not sure what the CCA is rated at though.

You can get it cheaper at Summit or Jegs.

Any chance you could take a pic of the terminals that you crimped or soldered onto your battery cables? I looked on Brailles site, but they don't show any terminals.

Additionally, what gauge wire are you running? I was planning to run 2 gauge, as its more manageable than say 0 gauge, which gets tough to go around corners.

My compression is decent, just under 11:1, what is yours? Just curious if yours is around mine, and if you've had any issues with starting, like in hot weather, etc.? I have a torque-reduction starter too, so that should help.

[never]

They don’t really have standard battery terminals. The cables just need 1/4” end ring terminals and you bolt those to the battery. So you can run whatever you want for cable.

I’m running 2 gauge on mine, 4 gauge alternator wire, and multiple 4 gauge grounds (battery to frame in the back, front, etc). No issues with the car. Battery power/alt power (when running) everywhere in the car.

My compression is 10.5:1 with a big turbo and heavier oil (15-40). Starts fine in all weather...but I haven’t tried to start it in anything colder than about 4-5C (whatever that is in F).


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[wdanison43103]

Are you using standard wire? I would recommend getting welding cable in 1/0 or 2/0 just so you have no worries of voltage drop etc. plus the welding cable is very flexible since it uses tons of super small strands


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[vdubn]

Are you using standard wire? I would recommend getting welding cable in 1/0 or 2/0 just so you have no worries of voltage drop etc. plus the welding cable is very flexible since it uses tons of super small strands


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Welding wire made of Tinned Copper is what I will be running, but honestly, it seems like 1/0 or 2/0 would be too big, and from all of my research, overkill for the kinds of current that our starters and alternators demand. It certainly won't cause any performance issues to run that big of wire, but trying to maneuver that around bends, through firewalls, etc. gets really tough... even with the finely stranded wire. Totally up to each person, but 2 Gauge is what I will run for the negative, and maybe 1/0 for the long battery positive lead running through the car. Considering that 6 gauge was factory, 2 gauge should really be fine.

[vdubn]

They don’t really have standard battery terminals. The cables just need 1/4” end ring terminals and you bolt those to the battery. So you can run whatever you want for cable.

I’m running 2 gauge on mine, 4 gauge alternator wire, and multiple 4 gauge grounds (battery to frame in the back, front, etc). No issues with the car. Battery power/alt power (when running) everywhere in the car.

My compression is 10.5:1 with a big turbo and heavier oil (15-40). Starts fine in all weather...but I haven’t tried to start it in anything colder than about 4-5C (whatever that is in F).


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Thanks for passing on what you are running, that is exactly what I will be running. As for your engine setup... oh man, I was going to do the same thing as you... run high compression and a turbo or supercharger, I ended up forgetting to tell my builder to set my ring gap to .035 (better for forced induction), he set it at .025 which was what Keith Black recommended for NA applications. So, probably not safe for me to add a supercharger down the road.... Curious what you set your ring gap to, running 11:1 with a turbo?

[never]

Thanks for passing on what you are running, that is exactly what I will be running. As for your engine setup... oh man, I was going to do the same thing as you... run high compression and a turbo or supercharger, I ended up forgetting to tell my builder to set my ring gap to .035 (better for forced induction), he set it at .025 which was what Keith Black recommended for NA applications. So, probably not safe for me to add a supercharger down the road.... Curious what you set your ring gap to, running 11:1 with a turbo?

Not sure what the gap is...whatever the engine builder set it up with. He knew the planned combo and it works so I would assume it’s all good.