After my post, I read another 100 posts and found some other pictures as well. All your great advice regarding the post caps, checking the water level in each cell, and cutting of the plastic base are greatly appreciated. It did take a lot of hunting to piece together all the facts, but it is great to know that the 51r will squeeze in and save me a lot of money and ultimately be a better battery than the Honda OEM. Thanks also to MTLian for posting this latest picture of the Kirkland battery. While my water levels were quite low in most of the cells, I'm hoping the Honda battery (unknown age) will last me. I just hope that Costco doesn't decide to stop selling the 51r due to low sales. Also, is there a reason why the battery NEEDS to sit on the plastic base? Is there any danger in having the battery sit on the metal base which is below the plastic?

 

In the unlikely event of a leak of battery acid (unlikely because of the "sealed" nature of modern batteries), or the more likely event of accidental overfilling of the cells), leaking acid will cause severe corrosion of the steel battery platform. When I installed my Kirkland 51R, I placed a sheet of 1/8" thick rubber under the battery to protect the steel platform.

 

What's wrong with the OEM? Do you mean what came with the car from Japan or what the dealers are actually selling? The reason I ask is because I have run into this with Yausa motorcycle batteries, meaning some last a very very long time and others are very short lived.

My motorcycle mechanic worked for Honda for 30+ years and believes the issue is there are 2 different grades of the their batteries. One that is shipped dry and the other shipped ready to go. He is not 100% sure but believes the ones shipped ready to go are the problem. At one time, I thought all sealed batteries were the same but he told me that with new bikes the dealer has to prep the battery and as long as he doesn't screw it up, those tend to be the long lasting ones. But he's still not 100% sure on that , other than there appear to be 2 different grades.

My first car, a Toyota Corrola had an Yausa that lasted 6 years on the original battery. I bought a small Yausa for a vintage Honda minibike in '99 from a dealer that did prep it and it lasted at least 10 years. It may still be working but bike is in storage. For Christmas 2000, I bought my mom a small Honda scooter. As my mom got older she was worried about wreaking it so it went into a shed. I bought a used Yamaha in 08 that needed a battery. Although it was undersized , I used the battery out of my mom's scooter and it worked fine. Still I wanted higher amp/hr battery so I ordered a Yausa over the internet . It was $80 and ready to go, no prep needed. It only lasted about 2 years and was dead. My mom's battery went back in the Yamaha and keep working until recently. That battery lasted about 12 years despite the fact we never cared for it at all.
My fit battery is going on 6 years and still going strong. But after reading your post , I wonder if the replacement OEM's are not dealer prepped and crapola like what I ordered over the internet for my Yamaha.

 

Good post HondaGuy. Yeah, my comments were actually an unscientific reflection of the hundreds of posts I read over the past couple of weeks. As a result of a lot of good advice on these pages, I uncorked all of the cell caps and refilled with distilled water. While everything is running fine, I am just glad that there is a Kirkland battery out there with our name on it. Knowing the 51r will shoehorn into our GD gives me great piece of mind. For one, I don't have to dole out any money to the lousy dealerships. And two, the Kirkland brand seems to be beloved by Consumer Reports. Those two reasons alone are good enough to down a box of California red wine. Which reminds me; it's time to celebrate. No driving tonight!

 

I have heard that Kirkland is good for the $$ and I think I will give them a try when the time comes, which is probably not too far off.

Here is some more folklore for you:

About 7 years ago, my dad was selling his scooter due to declining health. It needed a battery. I called my Honda (motorcycle) dealer to get me a replacement. He has always been very honest with me and this time was no exception. He told me to NOT buy the battery from him as the Yausa replacement OEM was $140. For a 250cc scooter! He told me a place near my work that had them for at least 1/2 price. I went to the place and yea it was about 1/2 or maybe even a bit more. I was talking with one of the owners and he told their batts are made in a former Yausa factory. In the usa? yes..on the east coast. So that told me they are now making them in America and I wonder if that is part of the reason some are very good some are not. I was at the same shop last year getting a batt for my Ninja bike. I was telling them how my mom's battery lasted for 12 years. They told me they could almost guarantee their batts would not last near that long and would only last a year or two unless I used a batt tender, which I do for most of my bikes as a precaution.

Enjoy the long weekend!