Overheating of the traction battery even though the cooling is fine.

Greetings from the Czech republic.

I am the owner of a Toyota Prius 3 with 230,000 km.
Summer has started for us and temperatures are rising to 30°C here. I always drive with the Hybrid Assistant app turned on. However, the temperature of the traction battery always rises to 48°C, when the recuperation is switched off during braking.

Because I thought the battery was poorly cooled, I disassembled the cooling from the seat to the fan. All ok, fan clean, tunnel clean. I didn't look under the battery cover. I always run the fan on level 6. The air conditioning in the car always goes to 22 degrees. Air at a temperature of about 33 °C is drawn into the battery fan.

According to Dr.Prius, my battery is at 60% capacity.

My question is: Can the battery overheat because it is already old? No error message pops up, no exclamation point. Yet.
I'll try to attach some photos.

 

Můj servis mi nabízí repasi baterie (pravděpodobně výměna špatných článků za nové) nebo novou baterii přímo od Toyoty. Za cca 2150 dolarů. Nevím, jestli je lepší oprava za neznámou částku nebo nová baterie.

 

My service offers me a battery overhaul (probably replacement of bad cells with new ones) or a new battery directly from Toyota. For about $2150. I don't know if a repair for an unknown amount of money or a new battery is better.

 

Thanks for the opinions. When I'm about to invest in a Prius, I came across an interesting Lithium project. Only on the website it is constantly sold out, is the project over?