MasterApex

Happy Father's day.
My battery died and I went buy a new battery. Both AutoZone and Advanced Auto database say the car battery is H8 AGM.
I bought one , took it home only to discover that it was way too big.
Long story short, I measured the battery dimension, it is actually H5 AGM.
So, save yourself time, make sure you order H5 AGM.

Replacing the battery is simple.
Remove the two screws from the tire inflator housing.
Remove one bolt that holds the bottom bracket
Remove two nuts that hold the top bracket.

There will be error message "Steering Support Restrictive ..." upon starting the car since the battery was removed.
Just turn the steering wheel lock to lock , it will reset itself.

RocketGuy3

I'm way late here, @MasterApex, but can you tell me in what dimension the H8 was too large? Was it too wide? If so, I noticed the same problem, but there was plenty of room to fit it, and I thought there may be value in buying a larger battery since my first battery didn't last very long...

Only issue was that there was one bolt on the floor of the housing for the battery I had to remove. As far as I could tell, that bolt wasn't serving a very important purpose (and it's been over a year now), but would still be curious to know if I made a booboo that I'll pay for with lost chassis rigidity at the track or something, hah.

Also curious if anyone knows anything about us needing to go to the dealership to have certain settings reset when replacing the battery...?

okie981

The Autozone Duralast that Autozone says fits the car will in fact fit the 981 cars, but it is longer and the bracket in the battery tray has to be moved to accommodate. Of course with a bigger battery you are also adding weight and that isn't popular with a lot of people, me included.

mannym5

Has anyone found an oem equivalent that is around the same weight or slightly lighter? All the agm’s at auto parts stores I found are huge at 60lbs. I believe oem is about 40lbs. I know antigravity makes very light ones, but I was hoping not to spend that much.

Antigravity

Hi Manny, if if's something you might be a little on the fence with in regards to price I just wanted to let you know we'll be having a sale on the automotive line coming over Black Friday. If not, completely understand but just wanted to be sure and mention.
Best regards,
Chad
chad@antigravitybatteries.com

ajw45

Awesome. This is the black friday sale I'm most excited about this year, thank you!

mannym5

thanks chad I will keep this in mind and look out for the sale. I may send you a secondary email with some questions if that’s ok.

Antigravity

Please always feel free to do so! chad@antigravitybatteries.com

okie981

I think Interstate offers one that is only slightly heavier than the OEM one, but lighter than the Autozone Duralast. Seems like it is around $275, IIRC.

NoGaBiker

Is there no programming that needs done if you put a new battery in?

bigwong

If you hook up a battery charger or maintainer to the battery terminals while you change the battery, the car doesn't know the battery has been removed and nothing is lost. Make sure you don't touch the hot (+) to ground and short it out, you should be good to go.

jakermc

Bummer, it seems I jumped the gun. I just ordered a 30amp H6 from you on Sunday

NoGaBiker

Thanks! That's solid. I figured the whole car would shut down if it found a new battery in there when you went to start it.

And congrats on your wong!

okie981

I've disconnected the battery on my car without adding any power supply to keep the car powered at least a dozen times if not twenty times. Never had a problem with anything not being as normal after reconnecting other than doing the power window reset by selecting up again once the window is all the way up and down again when it is all the way down.

I think with PIWIS you can reset the aging parameters for the battery that are calculated within the ECU. Don't know what that affects or helps with, but I believe that is the only thing PIWIS could possibly be needed for when replacing a battery.

DrBillyD

IDK about a GT4 but on a 2016 Spyder (981), an H8 will fit. The single bracket that holds the bottom of the battery has to be moved to the far end of driver's (left hand driver) side but there was a drilled and tapped hole for it.

However, I opted to replace with H5 (OEM size) as I didn't want the extra weight and don't need the extra amps as I don't drive it when it's less than 50 degrees outside.

I hook up a 12 VDC lantern battery to the jumper points in the driver's side fuse box and have retained settings.