Battery replacement, quick/fast charge is now slow charge

After several years I’ve replaced the first battery with a replacement purchased at Fairphone’s shop. With the new battery I experience that fast charging isn’t possible, with the old battery after I placed it back, it is possible again. I’ve no clue what the reason is for that.

What I’ve done? At first I had the old battery discharged down to around 50%, powered off the phone and replaced the old battery with the new one. I’ve turned on the phone and everything was fine so far. Several days later I’ve updated the phone to Android 13 after few recharge cycles. Prior and afterwards I’ve charged the battery with my Quick Charge capable charger (Qualcomm Quick Charge). When the charger is connected I can see at the bottom of the display that there’s something written regarding fast charging. So my assumption is that fast charging is working but from the first recharge cycle until now there’s obviously no fast charge available because a complete charge cycle from 0% up to 100% takes around 5 hours. With a really fast charge cycle this was in the past something around 1,5 hours so more or less 2% per minute. Now it’s around 0,33% each minute. During the fast charge cycle the charger gets slightly warm and also the battery. With the new battery this is not the case.

I’ve tried this several times and I’m really sure that this has to do with the new battery and not with Android 13. With the old battery (phone powered on or off) fast charging is possible, with the new battery not. In both cases on the screen is visible that the the charging takes place in fast charge mode.

My assumption is that this has perhaps to do with something inside the battery like a digital identifier which is not known from the new battery and so fast charging is disabled. This battery ID is well known for the old battery and then the fast charge mode is available. If that is not the case is could be also possible that the new battery is simply not capable to handle a fast charge cycle.

Has anyone an idea why I can’t fast charge the new battery and how to solve it?

Below there are these two batteries. The left one is the new battery, dated 2023/03/24 (at the botton right) and the right one the old battery, dated 2019/09/02.
The difference between both are that the new battery has around 2% nominal less capacity (new: 3000 mAh, old 3060 mAh) and the manufacturer is obviously an unknown one while the old battery was made by Fuji Electronics. That’s all I know.