In retrospect, after installing the new battery, I came to realized that original battery had been at below ~70% capability for most of its life beyond probably 1 year. Let me explain. Even after a full overnight trickle charge the OEM battery would start the GT-R just fine, but the starting would be somewhat sluggish, almost as though the starter was not sufficient to crank the engine over. This behavior, to me became normal over time, but it was not until the new battery was installed that I realized how snappy the GT-R startup can actually be. So to those on stock GT-R battery, I urge you do a simple voltmeter test.
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| Topping off new battery. |
So I used some simple procedure to test the battery. Why? Because it is winter and I don't have anything better to do. And I did nto want to have to remove the battery, take it to a shop and have them tell me that it just needs a good overnight charge.
1. Charged the battery using a 8A/6A/2A Boost/Normal/Trickle Charger over night. I have a $20 Stanley charger.
2. Removed the charger and put a voltmeter (multimeter) on the battery immediately and noticed a nice 13.3V charge which was dropping down slowly.
3. Measured the voltage across the battery at various time intervals in a cold garage. Basically after 8 hours the resting state is reached.
4. Compared it to the battery voltage on healthy battery from my Nissan Truck and also repeated the test with new battery.
All batteries have a nice high residual charge once the charger is removed, it normalizes quickly, after that the drop slows down; except if the battery is going bad then it drops quickly and achieves a final resting voltage. The best way to get to that is 24hrs with no load (no starting, no accessories). As you can see my truck and new battery were at 12.74V resting voltage after 24hrs and the OEM GT-R one was 12.2V.
There are multiple charts on the internet that show the voltage vs. condition. This is the one I used is below. There are complicated charts that show drop of each cell with temperature and specific gravity. But, surprisingly dropping temperature from 80F to 20F only changes the values by 0.08V. So 0.02V per 10 F drop, which is nothing really. It is an unhealthy battery which suffers quickly in the cold.
As a final hope to revival. after the OEM GT-R battery was removed, I removed each cap from the battery and topped off with some distilled water, considering that 5 years resulted in some evaporation, using a syringe up to the MAX line of the OEM battery. Ran through the charge cycle overnight again and monitored the voltage drop. Same results. Finally took the battery into a local O'Riley Parts, who put it on the battery Tester for free and it came back with 65% Life! So the charts on the internet work! The trick is checking the battery after full charge and 24 hours of no load.
Unlike most things in life, 70% of a battery doesn't mean it still has 70%useful life, In my opinion if it drops below 80% time for a new battery.
After much searching and reading forums and reviews, also based on local availability and warranty, I decided to go with an Interstate MT-51R battery. It has 500CCA (Cold Crank Amps) and weighs 27lb. Come with a 5 years warranty and is made locally to me. Well worth the 3lb increase to get a few more CCA compared to stock. I think these are the batteries that Nissan uses in non-GT-R applications and I have never had a problem in any other Nissan or Infiniti in the last 10 years.
While it may appear that there are many battery choices, it appears that there are simply 3 main stream manufacturers and everyone else rebrands. e.g. Sears and Walmart come from the same source. This guy has good information, too much to ever need.
Basically the GT-R uses a 51-R model battery. The Stock battery is rated at 433CCA and weighs ~25LB. The specs for the Interstate is below.
Product ID: MT-51R
Cranking Amps: 625
Cold Cranking Amps: 500
Voltage: 12
Capacity: 75
Termination: Common Code A
Weight: 27.9
Width: 5.13
Length: 9.38
Height: 8.88
Plates: 24
WET/DRY: W
It is simple 15-20 min swap of the battery.
How to change your battery without paying the GT-R Tax:
How to change your battery without paying the GT-R Tax:
Step 1: Buy the replacement battery of your choice and open the hood.
Step 2: Roll the windows down while you still have power.
Step 3: Record your stored radio station presets as those will get wiped.
Step 4: Remove the battery cover plastic by releasing the 2 tabs.
Step 5: Remove the plastic retainers shown in the picture.
There is plastic tab under the cover that looks like this (below), it maybe hard to remove, it required quite a bit of force to pull straight up. Even then it came out of the wrong end, so big deal, head up.
Step 6: Remove the plastic retainers shown in picture below in green. Pull up each of the 5 little white tabs that are connected to the weather stripping.
Remove the additional 2 plastic retainers that are holding the plastic finisher underneath the wiper.
There is no need to remove the wipers of the entire finisher, the battery can be accessed by simply moving the finisher back and up. The finisher under the wiper should be able to be moved aside enough to give access to battery mounting posts.
Step 2: Roll the windows down while you still have power.
Step 3: Record your stored radio station presets as those will get wiped.
Step 4: Remove the battery cover plastic by releasing the 2 tabs.
Step 5: Remove the plastic retainers shown in the picture.
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| Remove Pastic Retainers |
There is plastic tab under the cover that looks like this (below), it maybe hard to remove, it required quite a bit of force to pull straight up. Even then it came out of the wrong end, so big deal, head up.
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| Front Clip holding Finisher. |
Remove the additional 2 plastic retainers that are holding the plastic finisher underneath the wiper.
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| Remove more clips and fasteners |
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| Pull up Finisher under Wiper, no need to remove it or wiper. |
Step 7: Remove the Negative -VE terminal of the battery first by using a 10mm wrench. Always remove -VE first so as to avoid a mistaken short. Tuck the terminal lead back. Put back in reverse, -ve 2nd.
Step 8. Remove the Positive +VE terminal of the battery second. Tuck it away carefully not to damage the fusible links. Always remove the +VE terminal second so that if the wrench slips it does not short with the car's body which is essentially the -VE. Put back is in reverse, +VE first.
Step 9: Using a 10mm socket or wrench remove the rear battery holder nut connected to the post. Remove the cross member. Do not let the post fall, otherwise you're gonna have a bad day. Remove the post and put it aside. DO NOT let the cross member short between the -VE and +VE terminals.
Step 10: Using a 10mm socket or wrench remove the front battery holder nut. The front post is supported by a small plastic tab which prevents it from falling down as shown below. The post can be left in place or it can be removed. Don't drop it into the engine bay. Now remove the cross member.
Step 11: Push the finisher below the wiper back a little and pull the battery up by tilting it a little. Do not tip it enough to cause any leak of acid.
Step 12: Make sure the battery tray is in place. It slots into two holes and does have a little movement. Place the new battery in the same position. +VE terminal towards the inside. The nice little plastic caps on the Interstate battery protect from any shorting. You will need to push the front finisher up a little to get the battery in.
Step 13: Once the battery is in. Test fit the +VE terminal and move the battery as needed to ensure that the terminal goes back in the same position. Look at the pictures above for exact angle position of the +VE terminal with stock battery. Remove the +VE terminal.
Step 14: Put back the bottom of the post into the slots one at a time, and make sure NOT to drop them. While holding each post, place the cross member in and lightly thread the nut to hold the posts and once everything is set, tighten each nut for both the posts. DO NOT over-tighten.
Step 15: Connect the +VE terminal first. Clean if necessary. Tighten the 10mm bolt. Do not over tighten.
Step 16. Connect the -VE terminal second. Clean if necessary. Tighten the 10mm bolt. Do not over tighten.
Step 17. Put the finisher under the wiper back in place. See picture below if you have forgotten the placement relative to the weather stripping on the windshield. Put the 2 plastic fasteners to hold the finisher.
Step 18. Snaps the 5 white plastic tabs for the weather stripping.
Step 19. Place the battery area finisher back into place. If the long white plastic tab was improperly removed, then put it back and push it though the hole in the body. Put back the 5 black plastic fasteners.
Step 20. Put back the battery cover. Start the Car. Restore the radio stations. Do not forget to adjust the audio properties - Bass, Treble, Fade, etc.
Enjoy the new battery and saving a few $ on GT-R taxed labor and knowing it was a job well done.
With the new battery in and fully charged, my GT-R has sat for about 3 weeks without moving, as I was traveling, and it started snappily on the first try despite a few nights of going below 0F.
Step 8. Remove the Positive +VE terminal of the battery second. Tuck it away carefully not to damage the fusible links. Always remove the +VE terminal second so that if the wrench slips it does not short with the car's body which is essentially the -VE. Put back is in reverse, +VE first.
Step 9: Using a 10mm socket or wrench remove the rear battery holder nut connected to the post. Remove the cross member. Do not let the post fall, otherwise you're gonna have a bad day. Remove the post and put it aside. DO NOT let the cross member short between the -VE and +VE terminals.
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| Battery Mounting Pieces. |
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| Plastic Tab that hold mounting post. |
Step 12: Make sure the battery tray is in place. It slots into two holes and does have a little movement. Place the new battery in the same position. +VE terminal towards the inside. The nice little plastic caps on the Interstate battery protect from any shorting. You will need to push the front finisher up a little to get the battery in.
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| New Battery is in! |
Step 14: Put back the bottom of the post into the slots one at a time, and make sure NOT to drop them. While holding each post, place the cross member in and lightly thread the nut to hold the posts and once everything is set, tighten each nut for both the posts. DO NOT over-tighten.
Step 15: Connect the +VE terminal first. Clean if necessary. Tighten the 10mm bolt. Do not over tighten.
Step 16. Connect the -VE terminal second. Clean if necessary. Tighten the 10mm bolt. Do not over tighten.
Step 17. Put the finisher under the wiper back in place. See picture below if you have forgotten the placement relative to the weather stripping on the windshield. Put the 2 plastic fasteners to hold the finisher.
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| Finisher Position relative to weather stripping. |
Step 18. Snaps the 5 white plastic tabs for the weather stripping.
Step 19. Place the battery area finisher back into place. If the long white plastic tab was improperly removed, then put it back and push it though the hole in the body. Put back the 5 black plastic fasteners.
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| Everything Assembled. |
Step 20. Put back the battery cover. Start the Car. Restore the radio stations. Do not forget to adjust the audio properties - Bass, Treble, Fade, etc.
Enjoy the new battery and saving a few $ on GT-R taxed labor and knowing it was a job well done.
With the new battery in and fully charged, my GT-R has sat for about 3 weeks without moving, as I was traveling, and it started snappily on the first try despite a few nights of going below 0F.
