My Battery is bigger than yours.
 

It all started when I tried to start my car, and it won't crank. I'm thinking WTF. It work fine, and ran fine last night. I figured it might be the battery. I pull out my battery charger, and I see the thing go up to 16.3 volts on my charger. I didn't think this was normal. I usually charge my battery once a year for good measure. I never seen it hit 16 volts period. So I unplug the charger. I wait for a bit, and try the to start the car again. This time the charger stays in a normal range, starting from 11.xx volts to around 14.3 ish. The battery charger indicates that my battery is 100% charged. It seems a little odd because I only left it there for around 20 minutes. Anyways, I tried starting the car, and nothing happens.

The battery that was in my car today, was an Optima Yellow Top group 51 battery. They don't make the optima group 51 yellow top any more. I wanted another optima battery, and I figure I'd get a red top, because I don't really use my audio with the car off. I figured, I just need a good starter battery. There are not many places here, where you can just go in and pick up an optima battery around my city. Only small performance stores usually sell them, even then, they usually only have a few in stock. So I end up going to Sam's Club, because I heard from someone that they do sell Optima batteries there.

So I get to Sam's club, and I see 2 different red tops, and 1 yellow top. One of the red tops were clearly too wide to fit into the 7thgen civic. The other red top I bought was pretty wide compared to the stock size battery. However, I figured it might fit, but it'll be a tight squeeze if it does. So I bought a group 34/78 red top battery, not knowing if it'll fit. So I take my old battery out.

http://www3.sympatico.ca/phuvong/bat1.jpg

Oh that's not dirt on the battery, well some of it is. Most of it is that rust proof oil thing that they use to spray your car. I do it every year. As you can see, the battery is fairly small. Its skinny and tall.

http://www3.sympatico.ca/phuvong/bat2.jpg

Ok, so the battery fits, even with the stock battery holder (plastic holder thing underneath the battery). The one thing that doesn't line up is the battery tie down. So what I did was take out the metal stick part which hooks onto the car. I used some twist ties instead. Yeah its a little ghetto, but it gets the job done. You can see some of the twist ties in the picture above.

http://www3.sympatico.ca/phuvong/bat3.jpg

Everything was a piece of cake. I had to flip the battery the opposite way, otherwise the terminals would be on the wrong side. Only one issue though. The battery I bought has side terminals, and it does have the stock covers on the side terminals. However, the cover on one of the side terminals is rubbing against my intake. It pushed it in slighty, but nothing to worry about.

The good news though. 1000 cranking amps, and 800 cold cranking amps.

I hope this helps anyone who wants an optima battery for their 7thgen, yes it'll fit, with minor modifications. Oh, it may not fit if you have the stock intake box. I'm not sure, because I don't have mine in there.

Re: My Battery is bigger than yours.
 

I had this size in my civic and it worked fine. I removed the plastic stuff and used the stock tiedown. Worked fine for me and is still in there since I've sold it.

Re: My Battery is bigger than yours.
 

ive been thinking about going with a bigger battery too, I need room under my hood so ive been debating putting a big battery in the trunk. Since I already have 4 awg going to my amp, i think it'll be a pretty easy setup.

Re: My Battery is bigger than yours.
 

yeah they discontinued the grp51 yellow because it sucks and barely lasts 2 yrs. ive never had problems using a regular $50 battery from advance auto parts. starts fine even in extreme cold and never gave me weird problems like optima did. higher amps is really a waste for a civic anyway but good job making it fit.

Re: My Battery is bigger than yours.
 

Damn your old battery is dirty as hell. Good Job on making it fit. You also have a higher reserve capacity now too, so you can listen to your system with your car off longer.

Re: My Battery is bigger than yours.
 

I try not to use my system, when the engine isn't started.