It arrived in an open bag with the MI logo, supposedly genuine... I put it in the phone, it works, I can't say otherwise, but it lasts exactly as long as my old, worn-out one. I waited for a few cycles for the phone to get used to it, but nothing... I measured with a USB analyzer and it shows a capacity of about 50%, that is, around 2500mAh (3000 on the analyzer without the conversion from 5V)... So... The aftermarket is new with lower capacity OR the used old one in, let's say, good condition... I am very disappointed as I put in so much work for an unexpected result... I'm thinking of sending it back to get my money and IF I find a real 5000 new one... Otherwise, I'll put my original one back... Even if it's worn out... There's no point in such a change with the same performance as the old one...

I forgot to mention that my old one says year 2019, when the phone came out... Makes sense... The new one says 2023 as the year... If that means anything... MI, chatgpt told me, DOES NOT sell batteries... So this is the new aftermarket as I said with lower capacity OR the used original... The thing is, it has an MI logo with 2023 manufacturing... The redmi 8 series wasn't sold as a new device in 2023, I think... So it's questionable how such a battery was produced in 2023...

Okay, in an emergency it saves you if you just want a battery... But it does NOT seem to be 5000... My old 9T and 9A with 5000 batteries, years old, charge more in capacity...

I used the phone several times open to calibrate, for the phone to learn the new battery, and charged a few times with the phone both on and off to get a correct capacity reading... But as I said, the treasure was coal... The battery curve looks weird... The % drops quickly and then empties more slowly... The phone shuts off at 0% but it seems the battery still has more to give... Batteries don't fully discharge of course, but something seems off...

I'll try a few more and if I don't find a 5000 battery, I'll let it die with my original even if it's worn out... Such mediocre solutions make no sense...

Personally, I've started the return process but I'm doing a few more cycles just in case...

I've also put the USB analyzer to measure my other Xiaomi with a 5000 battery to compare mainly 0-100 with the phone off and only with a 5V charger... Quick charge doesn't measure correctly due to voltage fluctuation... Normally I'd change the battery again but with all the opening and closing, the phone will become a sieve... New phones with built-in batteries are hard to change...

If it settles even a little, maybe I'll avoid the change... We'll see... Anyway, this is my experience...

Just for the record, the original battery is 4800/4900 at full capacity at 3.85V or 19.25Wh (19250mWh). On a USB meter, it should show something between 3500-4200 at 5V for someone to say it's OK...

For questions, ask chatgpt and it will cover you...

Also, I forgot to mention that mine shuts off at 0 but when I try to turn it on again, it turns on and off, it doesn't show me 0% as it should... Sometimes it starts charging from off at 15%... Generally, quite suspicious signs... That's it... Finally, I apologize for the long text with perhaps not easily understandable information...

But you'll say, with 7-8 euros in the end, what are you looking for...

At least, though, they should state that it's lower capacity and aftermarket OR Used/Refurbished... For genuine, it doesn't sit well with me even once... Nor for good quality aftermarket...

I'm seriously considering sending it back even though I'm too lazy to open it again...

While the indicator has reached 0% in aida64 it reports that it still has 1500mAh...

After it shuts off, if I leave it for a few minutes it turns on again without charging at 15% and while the voltage is at shutdown level... That is, 3.2V. I put it at 1%, it charges, and when I turn it on, it shows 45%... Of course, the voltage is again at shutdown level 3.2V since it didn't have time to charge even 5 minutes... Truly disappointing...

I'll do two more cycles in case calibration finally works out, personally I doubt it but I'm doing what I can to avoid opening it again...

If it doesn't settle, it will go back, what can I do... As we said... We didn't do all this hassle to go from the worn-out original to just anything...

I want to try quick charge too but I'm a bit afraid with such a battery...

All the data points to low battery quality though...

From 45 it went to 0 and shut off...

Makes sense since it didn't charge much. The indication is illogical.

Now I'm charging it on with quick charge from 1% so I don't have to wait... Calibration isn't affected by quick charge. Then discharge. Another charge with the phone off at a steady 5V for accurate measurement... No quick charge here... And if not, return, even if I don't feel like opening it again and being without a device for days until the replacement arrives...

I'd put the old original back to be done with it. But then I'd have done all this for nothing at all... What can I say... We'll see... Just be careful with these batteries that are out there...

What I understood though, with chatgpt's help, is that the battery's BMS reports to the phone's firmware that the cell is 5000, while it's actually smaller... I did two more 0-100 cycles, I think it settled a bit but still not like a real 5000. On YouTube use it lasts about 7 hours... Because I don't feel like unscrewing the phone again, I'm hesitating whether to leave it or not... If I did all this work to have the same performance as the worn-out original, then it's pointless... But the phone still doesn't measure it very well... That is, it's at 0 when it should be at 20 according to the capacity aida64 shows...

Then it shut off at 0 and turned on at 5, which means with cycling it's starting to sync with the phone's meter but still not like a 5000...

On the scale I weighed them, the original is 67 grams and this one is 61 if that says anything...

I forgot to add that the original has a QR code and on the connector while the bulk one doesn't...

Anyway, the one I got doesn't seem like a 5000...

More like a 3500 to me... I'll post measurements with photos later. We're talking about a lifespan of around 70%...

That's it... And I'll see what I'll do...

A genuine on a USB analyzer should give...
4200mAhx5V=21000Wh
21000Wh/3.85V=5454mAh
5454-15%=4636mAh
And below what this bulk one gives me...
3200mAhx5V=16000Wh
16000Wh/3.85V=4155mAh
4155-15%=3532mAh
===
70% health
30% loss.

After a few months of use and charge/discharge cycles, aida64 reports a capacity of around 4000...