DIY Battery Replacement-50i

[Tressler]

Hi all,

After some check engine codes were thrown and checking out the batteries it's seems like they are due for replacement. I've not replaced them in my ~2yr of ownership so this does seem to line up.

I never in my lift though replacing a battery would be so confusing! I've tried reading up on some threads here but seem to just confuse myself more.

1) I have two batteries, a 90ah and 50ah
2) what exactly should I order to replace these?
3) is there an upgrade or similar for the 90ah one that I should get?
4) what do I need to do regarding "registering" my new battery? Can I even do this myself?

Sorry for the noob questions and thanks in advance for the help!

[CatalinP]

You can replace the 90Ah one with the bigger 105Ah if you wish, but make sure it is AGM type.
Replacing the battery with a new one of the same size needs registering.
Replacing the battery with a bigger one requires a more complex coding.

Both can be done using ISTA+ and ENET cable.

[turboawd]

The main battery is a H8 AGM i believe

The second battery is hard to find.
Will cost 400 at the dealer.

I Came across a prius chat, and this battery was mentioned. It looks it'd work. Same dimensions and looks like same battery case. Could be same manufacturer...
Search for this ACDelco® LN1AGM

$150 at rockauto

https://www.rockauto.com/en/parts/ac...M,battery,2476
I didn't buy it yet. Barely drive my x5 lately so i procrastinated...

[Qsilver7]

Are you sure you need the smaller 50 AH battery? It is "nursed" by the PCU (power control unit) and may still be in good health.

As turboawd pointed out...the smaller battery is much harder to find...but it is an H4/140R (LN1) AGM battery. You can see its specs listed at the bottom of the chart below. If you find an H4/140R battery...make sure that is an AGM battery.

[ponytuning]

Make sure the terminals are not corroded. I got several battery discharge while stopped messages after replacing the main one and noticed terminals on the aux battery were severely corroded, likely preventing it from being charged. After cleaning them with baking soda and recharging it I stopped getting battery messages. It's been almost 1 year since.