Question storage batteries

Thread Starter

electroenergy

Joined Jun 22, 2021
4
Can a battery specialist help me? i have xiaomi BM20 and fake Nokia BP-5L smartphone batteries and i want to store them long term are these batteries Li-Po or Li-Ions? what is the recommendation to store these batteries for the long term? the maximum as possible?
 

LowQCab

Joined Nov 6, 2012
1,307
They need to be fully Charged, and then Discharged to
a Voltage that is the equivalent of half way between fully Charged, ( around ~4.0-Volts ),
and the lowest recommended operating Voltage, ( probably around ~3.2-Volts ).

Half way, if I had to make a guess, should be around ~3.6-Volts.

Then, once a Month or so, test them to see that they are not "Self-Discharging".
If they get below ~3.2-Volts,
Charge them back up to ~3.6-Volts.
Keep them in a cool place where the temperature is relatively constant, ( Not-Outside ).
.
.
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Thread Starter

electroenergy

Joined Jun 22, 2021
4
A lot of people talk about different voltages 3.6v, 3.7v, 3.8v, 3.9v but I'm confused which voltage I should follow Do you have any studies or indications from manufacturers about long term storage voltage?

temperature in my city varies 31-34ºC
 

Tonyr1084

Joined Sep 24, 2015
6,452
Lithium batteries are good at storing their voltage for a long period of time. But they CAN self discharge over time. I have 16 used Li-Ion's that have been stored on my bench top for about a year. The good batteries resting voltage after having been fully charged is typically around 3.8 volts. Four of them have fallen to 1.3V, 1.4V, 1.8V and 2.7V. The low voltage batteries need to be properly disposed of because they're not going to be of any use and could potentially be dangerous.

Your question has inspired me to check the battery voltages, and it's probably a good thing I did. I thought these batteries were in better shape than they actually are.
 

Tonyr1084

Joined Sep 24, 2015
6,452
You realize the difference between those two numbers is a mere 2/10 of a volt, right? Likely any of those voltages will do - be it 3.6, 3.61, 3.62 (need I bee an arse about it?) up to the 3.8V range. HECK! Even 3.55V won't be a problem. Probably not even 3.54.
 

Thread Starter

electroenergy

Joined Jun 22, 2021
4
There is no difference in self-discharge at 3.6v and 3.8v?

Could someone tell me a good charger and discharger for the xiaomi BM20 and Nokia BP-5 batteries?
 

Audioguru again

Joined Oct 21, 2019
3,828
On the other website I told you that all the Lithium-Ion and Li-PO batteries that I buy come with a storage voltage of 3.75V to 3.8V.
I told you that my daughter's first cell phone Name-Brand battery has held its storage voltage of 3.7V for more than 20 years.
I told you that your batteries are cheap no-name-brand. Then they probably will not last long.
I told you that your charger is cheap and has a display that says "percentage" but nobody knows of what.
I told you that Battery University says to store a Lithium battery at 3.75V to 3.8V.
Now you ask the same questions on this website.
 

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