51R Interstate Battery in 2009 - won't fit, I swear
 

2009 Fit Sport, original battery if you can believe it, showed signs of failure the other day --> time to replace. So after researching this ad nauseum, watching every video and reading every blog I could find, I thought I could be a hero on my DW's daily driver. The road to hell is paved with good intentions as they say. Anyway, so far I:

1. Bought a 51R from Costco (Interstate battery fwiw)
2. Cut the right side of battery tray
3. Cut the positive cable hook on left side of tray
4. Cut the fins on the right side of the air filter housing

But to no avail. Even if I leave the tray out altogether, the battery is so wedged in there the top of the air filter housing won't fit. Something tells me not all 51Rs are the same size. No way this one works -- I think I need a good 1/2" less width.

Input?

I installed the same battery purchased from Costco, and replaced my original battery in my '09 last month. All I had to do is angle the battery without the battery tray. Unhook the positive cable stay from the left side of the mount, no cutting or cursing.

Wrong battery--It's not worth it!
 

IMHO its not worth putting the wrong battery in. Even if you can somehow get it in, you probably cannot really fasten everything as designed, so you risk the battery, or its connections, to move around if you have an accident. Is it really worth the risk of a fire? Why don't you get yourself a 151R and call it a day. They are cheap enough at Batteries Plus Bulbs, or you can pay a little more at most auto part stores.

Because the 151 is right at the ragged edge of being enough cranking amps to start the car reliably. (Yes I've measured it... ) And nothing ticks me off like a non starting vehicle. Plus with the 151 I can't run my radio (Stock) while waiting for the wife at the store, it will kill the battery.

If its an easy fit its worth it otherwise the next best choice is a Oddesey. Mine is held in with the stock holder and in the same location. With noting but a little sanding on the edge of a piece of plastic to get it in clean. YMMV I have a 2007 Sport Auto.

I chose to stick w/ 151R. What is right / wrong for each of us depends on personal specifics. I live in a temperate climate. The standby power risk is acceptable. While I'm all for a hack to get the thing in there, I didn't want a kludge and that's what I'd end up with. If only there was a battery sized between the 151R and the 51R. (DwTaylor at first I thought you were suggesting I get a minivan!)

I got the 51r at walmart. I nudged ever so slightly the air filter over by slightly loosening the bolts that were holding it down. I of course took out the plastic battery tray. I temporarily removed the cable from where it was mounted before putting the battery in and put it back when I was done. I put the 51r in at a slight angle. The hardest part was fitting the red cable back down onto and behind it. That was a bit of a squeeze, and getting the cable to fit and hold the terminals took a little bit of work.

@ interestingstuff: Thanks for posting your experience. The battery upgrade is on my list. :)

I've never understood the battery upgrade.

I live in one of the coldest states in the country and my Fits have never not started.

I never had an issue with the temperature. It's just the lack of battery charge that has been a problem for me.

In some cases I've been sitting in a parking lot enjoying some food and the radio... and then.. poof.. the car won't start again.

Or the trunk doesn't get closed completely, and the trunk light is left on without knowing and the car won't start.

Or I go away for an extended period of time and when I get back, the car won't start.

This might be less of a problem for people who drive more frequently and longer distances than I do, but this has been a problem for me through two batteries.

I've had an issue with temps. By the 3rd year the car was struggling on the coldest days. I could start it, but the auto-start would not do it.

I almost made it through 4 years, but one day it dropped below 0 and no cranking. >10 was fine. Luckily not on a work day! But you know, this was kind of upsetting to me. 3 years is not sufficient margin of safety; plenty of people push it to 5 and expect to get home when it's super cold out.

The battery is too small. Probably it's because it's the largest engine from this model (1.5L).

Costco does not carry the size. My tire shop did, but man it was an arm+leg ... surprised as heck to pay $150 for a battery change! As I told Wife: You don't have this problem if you buy a Ford :P

Can be worse, my BMW uses a gigantic AGM in the trunk. 235 bucks.. Exide.

yep, don't have to worry about the battery in a ford when the transmission doesn't work ! j/k
there is a chrysler where you pretty much have to take the front wheel off to change the battery

I have a Advance Auto 51r in my car. I also bought a universal battery tray, had it trimmed down to fit the battery incase the battery wanted to slide out.

I live where we can get below -40C -40F. My battery didn't freeze, but the engine did not start on a recent -38C morning.

I have an oil plug and a battery blanket plugged. I drove away while it was still plugged in and didn't notice the blanket was unplugged.

That is why the 151r is a problem