When people ask certain things (like trying to fit intakes and whatnot) people always respond "just turn your battery" like it's some cake walk 15 minute project. I have a feeling 95% of these people have never done it but just offer it up as some "duh" solution. Well it's not as easy as it sounds.

Anyways, I had a need to turn my battery and I spent a LOT of time figuring out how to do it easily. First off, you're NEVER going to do it with the stock battery. Sorry. It's just too big and bulky. And even if you do you're not going to gain much as the stock battery is almost square. You will only gain an inch or 2. Hardly worth the work involved.

It took me a LONG time to figure out how to do it the right way and I tried many different batteries until I found the right one. So I saved anyone who is interested in doing this a LOT of time. What I came up with is the easiest and best way to do it IMO and will gain you max room. The reason I did it was to clear the way for the DIY Volvo 850 CAI (note that the cone filter you see on the MAF is just temporary).

Anyways, here are the instructions:

Step 1. Get a Honda battery at your local parts store. The one I purchased was $65 (plus $8 core charge) and has 625 CCA. The stock wasn't mush more (700 I think), so this one was very close. It's the most powerful one of it's size I could find and starts the car just as well as the stocker, even in the coldest of temperatures. It's also 9bs lighter than the stock battery I was replacing so that is a definite bonus! The battery is used on most Hondas - I know for a fact it's used on all 92+ Civics, delSols, Acura Integras, and probably a million other Honda models. The parts guy just called it a "Honda battery". Any store will have plenty in stock. However, every battery store has "cheap" batteries for $39, middle batteries for $50-something, and high end batteries for $70+. I noticed the low end and middle batteries had significantly lower CCAs as the high end one I got. The $39 version of the Honda battery I got had something like 325 CCA, which is terrible and would probably not start your car in the dead of winter. I would NOT recommend getting the lower or middle end battery. If you want a stockish equivalent as far as CCAs is concerned, you have to spend the cash on the 5-year high end type battery. Mine was the "Duralast Gold" version. NAPA Gold are good batteries too. Deka makes great batteries too, and is what OEM is.

Here are the 2 batteries side by side:

It's hard to see from the pics but the Honda battery is a LOT smaller. It's shorter in length and width, but at least 2+" taller. The extra height makes room for large lead plates, which is how you can get the strong CCAs from the replacement battery because it probably ends up with a similar cubic volume as the stocker. And you have plenty of space for a taller battery in the engine compartment so you may as well take advantage of it.

Step 2. I used some scrap stainless sheet metal to build a battery tray. The tray is the sale length as the new battery for a tight fit, but the width is just slightly longer than the new battery. The reason for this is you have to allow room for the mounting bolts. I will take exact measurements later, but if I had to guess I would say the width is 1" wider than the battery. Also, if you don't have a sheet metal brake to make a tray like this on, you can simply put a short piece of wood i.e. 2x4 at the edge you want, put a c-clamp on it, and tap the overhang with a rubber mallet. It will form over the 2x4 and make your 90 degree lips. Once the tray was made, I drilled 2 holes in the battery tray for the mounting bolts:

Step 3. I bought some "J" battery tie downs at the auto parts store ($) and made an aluminum hold down from a strip of scrap aluminum (you can buy this at Home Depot ). I drilled 2 holes in the lips of the battery tray for the "J" tie downs, and test fit to make sure everything fits:

Step 4. Remove the stock intake and stock battery tray. You will use the exact same 2 bolts that bolted down the stock battery tray for the new battery tray. The frame rail is not 100% flat where the new battery tray will be sitting - the bolt holes are a little "sunk" down on that section of the rail. So you will have to put a few washers under the bolt holes of the new battery tray to get it to set level. If you skip this step, as soon as you tighten the bolts on the new tray the tray will tilt towards the center of the car cockeyed and the battery will not sit level. So the washers (or some other form of spacer) is required and not optional. I used stainless washers that were very thin, and used 6 washers for the hole closest to the firewall, and 4 for the hole closest to the front of the car. If you use zinc washers they will be thicker, so just adjust accordingly. Just set the new tray in it's place and you will be able to stack up a few washers and slide it in the space under the tray where the holes are and you will be able to gauge however many washers it will take to fill the space. Use only the number needed, no more or you will be raising the the tray up and it will lean the opposite direction towards the fender. Once you figure how many washers you need, slide the stack of them in place under each hole in the tray, and stick the bolts in to bolt the tray down to the frame rail.

You will also have to trim a very small section of the corner from the plastic frame that the stock airbox rests on using a Dremel cutoff disc. It will be obvious what you have to trim - the top left corner of the battery tray and battery will hit it and will not go into place without cutting it off.

Step 5. There is some sort of oval solenoid with a vacuum line (looks like the line that goes to the stock turbo gauge) screwed to the underside of the stock battery tray. You will see it as soon as you remove the stock battery tray. That will have to be relocated. You can see I relocated it right behind the + battery terminal to a hole that was on the fender. It's oval shaped and says "Volvo" on top. I just secured it with a nut and bolt. The solenoid is screwed to a metal bracket that can't be reused. Just unscrew it from the metal bracket and secure the solenoid itself to the fender:

Step 6. You have to extend the positive battery wire about 9" or so. To do this you simply buy a replacement positive battery terminal wire at the parts store ($6). I also bought a 2 gauge splicer at Home Depot ($2) in the electrical section. It's basically a little block of aluminum with a large hole drilled in each end, and 2 big screws that bite into the end of the wire when you tighten it down. You just strip the end of each wire, shove it into the hole in the aluminum block, and tighten the screw. Can't get any easier than that. Don't worry, it's designed to splice up to 2 gauge wire running 220v and 440v applications, so it can handle the amperage the car battery can put out no problem. The nice thing about the + terminal I bought at the auto parts store is that it came with a red rubber boot to protect the terminal. I can't tell you how many times I've arced tools to the + terminal accidentally. Once I extended the + battery wire I sealed the connection with liquid electrical tape, then once dry I wrapped the whole section in regular electrical tape, then finally wire loomed it just like the stock + battery wire.

Step 7. Bolt the new battery tray in place, put the battery in place with your tie down, run the + and - battery wires to it, and tidy up all of the misc wires hanging around with zip ties or whatever.

Completed pics:

Now you have a GIANT gaping hole with plenty of room for all sorts of goodies under the hood - intakes, FMIC piping, small animals, etc.

The only downside is that to change out the headlight bulb you will have to remove the battery because it's a pretty tight fit and there is very little room between the edge of the battery and the headlight adjustment post. But it takes all of 5 minutes to remove the battery. In fact, you probably don't even have to completely remove the battery - just loosen and remove the tiedown and shift the battery enough to get your hand where it needs to go. A small price to pay for the advantages of the rotated battery.

Finally, I'm sure some may say "why not just relocate the battery?". Well that would have been way more work and expense than necessary. And I have a wagon so I would have had to deal with a battery vent tube unless I wanted to buy a mucho $ sealed gel cell battery. And honestly moving the battery to the back isn't that great because you lose so much room in the cargo area with a gigantic ugly battery box (which runs $60 by itself anyways). Plus I don't like running live positive battery cable inside the cabin or under the car. No thanks. With my solution you can easily convert it back to stock for whatever reason.