Question storage battery

[tiago1986]

I was recommended to store Li-Po or Li-ion smartphone batteries for the long term with a charge between 3.75v and 3.80v, today I measured the voltage of the BM20 and BP-5L batteries and they are with 3.74v at this voltage. do I need to recharge again to 3.80v?

[tunk]

No. Monitor them regularly and if they drop below e.g. 3.5V, charge them to e.g. 3.8V.

[tiago1986]

i charged to 3.8v and stored these two batteries for 2 or 3 months and now they are at 3.74v and i thought it was to recharge

[Faringdon]

LiPo Cell Voltage:
The usable voltage range for a standard lipo battery cell is 3.2v to 4.2v. Any lower than 3.2v and the battery may be permanently damaged. Any higher than 4.2v and you significantly increase the risk of a battery bursting into flames.
So keep it above 3.4V and you should be ok.

LiFePo4 Is a bit lower voltage than Li-po, but you are not using that?

[tiago1986]

my batteries are xiaomi BM20 and Nokia BP-5L

currently their charge is at 3.74v do you recommend me to charge to 3.8v or not?

[Gyro]

It seems to me that you have covered this ground before - maybe 6 times! 

https://www.eevblog.com/forum/renewable-energy/temperature-and-voltage-keep-battery-lipo/

Go and re-visit your previous threads!

[Siwastaja]

If you measured voltage just after charging, that is not a reliable indication.

Now, after 2-3 months they definitely show the true open-circuit voltage.

Now, look again after next 2-3 months. If the voltage still continues dropping, then that's an indication of relatively high self-discharge cells, indicating poor cell quality. But don't make this conclusion yet.

[tiago1986]

I charged it to 3.8v, checked the voltage with a multimeter and kept the batteries for 2 or 3 or 4 months I don't remember after that period I tested it again with the multimeter and the voltage is at 3.74v. Will I need to recharge today to 3.8v?

[Psi]

Your question has been answered at least 3 times.

[Siwastaja]

Just record the current date and current voltage on a piece of paper. Don't do anything else. Measure again after a few months, if still interested.