to be honest quite expensive. canadian dealership selling for 90CAD.
i think a few us online dealership part stores were selling it around 45-50USD,
the Mexico one with the stupid notch thing was significantly cheaper like 25usd or something from that same place.
i know most would just cut it like the person above. but i'm anal/paranoid about these things. ie. if the battery ever leaked, i'd much rather it leak into the tray under it and not have acid all over in the engine bay.. but it is a very minor concern. and most wouldn't care.. but i'm stupid like that so i guess stupidity costs money haha.

whats the part number of the full size japanese one? i might spend the 90 CAD like you.

The part you want is : 31521-T5A-000 in the description it will say something like (B19L / B24L)
in diagrams they may show online shows the wrong part, but that is the correct part number. I think they just re-use the same diagram for both.

the shitty wrong part that came with our crappy mexico built fit is 31521-T9P-000 (note the P) in the description it would say something like B19

the main reason i'm changing to 51R is the really bad battery in my fit. i got it replaced once under warranty after year 1 already. and its dead again. its just undersized for the amount i drive... which is not too much.

Thanks for the part #, did a quick lookup, lowest is a used one on eBay for $45.

Your battery = dead often is likely due the environment you are in (Calgary, CA). I am in SoCal, so the original battery lasted a little over 4 yrs, when it started requiring me to push start a few times at times before the engine would fires up, it is time to replace it. Why for me? 51R battery(Costco) costs a lot less for more crank = no-brainer.

I had my 2015 Fit battery replaced at Pep Boys this morning. Bosch 51R with 25% online ordering discount and free installation. $125 with tax included. They trimmed the plastic battery tray to accommodate the larger 51R.

Nice. What did that cost and where?

I'm very envious that you got an Optima battery the Fit.

I have a 2015 Fit EX-L and the battery tray is longer than the battery. The battery looks like it belongs in a lawn mower but still works after almost 5 years.

My 2015 has the small battery and the tray is designed to "fit" the smaller battery. I will need to modify the tray to accept the 51R. I just saw 51R at Costco for $78 if anyone is interested.

I have a 2016 EX and an Autozone 51r fit perfectly

I have a 2016 LX CVT and Interstate 51r from Costco fits perfectly with no cutting. My car is a J-vin with the big battery tray.

https://cimg0.ibsrv.net/gimg/www.fit...2d9fe60288.jpg
.

I needed to replace my 2015 EX's original battery and went with a 51R based on what I found in this thread.

Using a Honda VIN decoder, it told me my Fit was produced by Mexico Honda Passenger Cars. It had the short tray, as seen below.

Hoping these pics and info can help someone out. Thanks everyone!
https://cimg8.ibsrv.net/gimg/www.fit...c540445a0e.jpg
151R (Left) 51R (Right)
https://cimg0.ibsrv.net/gimg/www.fit...b94b406131.jpg
151R (Top) 51R (Bottom)
https://cimg4.ibsrv.net/gimg/www.fit...7c2ffa52b0.jpg
Snippety-Snip
https://cimg7.ibsrv.net/gimg/www.fit...350e07252b.jpg
Made it easy and just cut off the right side.
https://cimg2.ibsrv.net/gimg/www.fit...cade0beb17.jpg
Trimmed
https://cimg3.ibsrv.net/gimg/www.fit...4a53dd9e83.jpg
51R sitting in the newly-cut tray
https://cimg1.ibsrv.net/gimg/www.fit...81d132b589.jpg
No battery tray
https://cimg5.ibsrv.net/gimg/www.fit...6ada7ee489.jpg
Battery tray re-installed
https://cimg6.ibsrv.net/gimg/www.fit...78bd0d1c07.jpg
Done!

I wouldn't have cut the tray like that. I think it would have been better just to cut the raised edge (only!) around the circumference of the tray as necessary and leave the bottom of the tray completely intact to provide maximum support for the larger battery.

I could have, but I'm comfortable with the amount of tray that remains and the fitment is still solid.

Sorry to resurrect an old thread. Do you need to use a memory saver or is it a straight battery swap? I've heard horror stories from people (with other vehicles, granted) that the car had to re-learn everything, idling, radio stations, etc. Thanks!

I don't remember anything being an issue because I did the install a while ago.

I would make sure anything pertaining to the radio, presets, etc. are written down before doing the swap. Better safe than sorry.

I also can't remember if you need your radio code:

https://www.rensselaerhonda.com/how-...da-radio-code/

I haven't switched batteries but I have disconnected the battery terminals in order to clean them (which is pretty much the same thing) and I don't recall any issues after I put the terminals back on the battery. I suspect that radio codes and the like are becoming a thing of the past because thieves no longer steal radios. They want your air bags, your alloy wheels and other things. Radios? pffft!

All my headunits (stock and aftermarket) have retained all the settings when the power was disconnected (or battery was so low that it essentially is dead.

The GK dash clock will need to be adjusted. The stock headunit will require a code, but if you hold power for a few seconds, I believe that it will accept that.

Don't recall any of that. In my 2018 LX the clock picks up daylight savings time changeovers automatically (presumably from local radio stations) so I've never had to adjust it. You just have to wait a while for that to happen. I would think that that would also correct any time loss from disconnecting the battery. Again though, it's not instantaneous, you have to turn the car on for a few minutes. I don't believe this feature was in earlier GK models.