I have the Interstate AGM MTX-35 (CCA 650 RC 100 Ah 55)
in my 2021 Crosstrek Limited.
I have the A-S-S Eliminator installed as well

 

I have the Interstate AGM MTX-35 (CCA 650 RC 100 Ah 55)
in my 2021 Crosstrek Limited.
I have the A-S-S Eliminator installed as well

Thanks. Do you have any idea why Interstate has that technician alert about it taking longer than 20 minutes to install and telling technicians to download the instructions? If you installed it yourself, did you have to do anything out of the ordinary to get it to fit?

 

I liked the Batteries Plus Bulbs X2 Power AGM battery.
The OEM LN2 in my 2024 works great, I just keep it on a battery charger.
There is a TSB for upgrading the battery on your 2021, I think, I just don't know what it is.

 

Group 35 battery fitment isn't the issue. Most, if not all, Group 35 batteries will fit the Crosstrek's battery tray. Group 35 is one of many Battery Council International (BCI) sizing standards.

The additional minutes quoted for the battery swap is likely due to dealing with the battery monitoring "block" on the negative (-) battery post (finicky) and having to hook up the Crosstrek to another 12VDC power source when the defunct battery is pulled, so as to not lose your BCM and radio preset settings, plus avoiding a throttle re-learn.

I swapped my 2021 Crosstrek's OEM battery for an Odyssey ODP-AGM35 using a spare 12VDC auto battery and this OBD II Vehicle ECU Emergency Power Supply Adapter. Working slowly and methodically, it took me 45 minutes. But then, I'm an old fart. YMMV.

 

Shame the units that hold those settings and throttle data don't have some sort of resettable non-volatile storage, seems like an easy problem to avoid for almost no extra cost on Subaru's part.

 

Good idea. Coin battery? Usb? SD card?

 

Does a 2021 need to Register the new battery???

 

Nope.

 

I disconnected the ground on my original battery and connected my 3 amp charger. It started charging 1,500 ma and after 24 hours was charging 500 mili amps. I lit the dash up after reconnecting the ground for one minute without touching the pedals. It idles OK. It remembered the radio and one touch down window settings.

 

We’re considering a non-OEM battery to replace the stock battery that has lasted three and half years so far. The Interstate Premium MTX-35 AGM battery has the following note regarding installation on its web page for our Crosstrek:

“Auto Technicians Note: Average install time is longer than 20 minutes. Log into your dealer account to download the instructions”

That note made me wonder if there is fitment issue with that battery or other group 35 AGM batteries I'm considering. If any of you have installed one of the three batteries below in a Crosstrek of this generation please post whether there were any additional steps required to get the battery to fit in the tray or re-attach the cables. I usually replace batteries myself so I'm looking for one that won't cause headaches in the process.

1. Interstate Premium MTX-35 AMG 650 CCA
2. Duralast Platinum Battery Group Size 35 650 CCA 35-AGM
3. DieHard Platinum AGM Group Size 35 650 CCA

Thanks in advance for the information.

PS: We always turn off the Auto Stop Start function each time we use the vehicle.

Ironic - just had Autozone install the Duralast Gold yesterday in my 2021 Limited.

I did some research and found that our cars don't need the Duralast Platinum and that the Gold was fine and...much less expensive.

And, you don't have to reprogram anything - just got in - it cranked really well and drove off.

 

Thanks. Good to know that reprogramming is not needed. I saw a reference while searching the forum where someone mentioned something about installation issues with the Duralast in another post but I was unable to find the post that was referenced. I assume that Autozone either didn't encounter those issues or they didn't mention them.

I like the idea of the AGM battery design so I'll probably pay the premium to get one. The OEM battery is still alive but cranked a little slowly during a very cold start the other day. It's over three and half years old and spent a lot of time in the Florida heat before we moved back north. I'll replace it soon since my wife hates being stranded and she's the primary user of the Crosstrek. I'm now down to deciding between the Duralast and the Diehard. There are too few Interstate retailers near where I currently live so I've ruled that out even though I was happy with them in the past.