Does this just apply to just the Prius or all Gen 5 Hybrids? I have a 2025 Camry that apparently has a flooded battery located in the trunk area.
I don't know, but I would upgrade to an AGM battery when I needed an out-of-warranty replacement. The reason why OEMs use flooded-cell batteries is because they cost much less for them, but for us buying an aftermarket battery, they cost the same; so, there is no point in opting for a far inferior technology.
If, as implied, they have differing charge requirements, could that not cause an issue? IIRC my 2017 Prius had a flooded battery under the hood. I replaced it once between October 2016 & September 2024 when the car was totaled.
I and @Roy Peterson both have an AGM battery in my Gen 4 Prius Prime and in his Gen 5 Prius Prime, and we have been observing much better performance with it. In fact, Roy was having problem with his OEM flooded-cell battery, and he is very happy with the AGM battery now. See the thread I linked. Virtually all owners report poor performance with their OEM flooded-cell battery. One possibility is that the BMS was originally designed and tested for an AGM battery, but Toyota replaced it with a flooded-cell battery during production to reduce the costs, which is causing problems with the 12-V battery. The even smaller Gen 2 and Gen 3 batteries were AGM, and they lasted for ten years without any problems.
Thank you. I had no issues with my 2017 Gen 4 Prius and did replace the flooded cell battery with another one due to aging out.