Question storage batteries

[cloudff7]

I own xiaomi BM20 and Nokia Bp-5L 1800mah batteries and I saw in a region with average temperature 35-40C what long term storage voltage should I put on these batteries?

 

[OffGridInTheCity]

These are lithium-ion. I store mine at 3.7v +/- a bit (3.6 or even 3.8) - somewhere in the middle voltage range - reduces internal chemistry stress that is created at fully charged or fully discharged.

 

[cloudff7]

I have two of these batteries that are charged at 3.8v is it necessary to discharge to 3.7v for long term storage?

 

[OffGridInTheCity]

I have two of these batteries that are charged at 3.8v is it necessary to discharge to 3.7v for long term storage?

3.8v is OK.

 

[cloudff7]

the temperature where I live varies from 35-37C and these batteries models BM20 and BP-5L charged at 3.8V will I need to re-charge after how long?

the charge drops and how many times do you need to charge it again before it damages the battery?

 

[OffGridInTheCity]

the temperature where I live varies from 35-37C and these batteries models BM20 and BP-5L charged at 3.8V will I need to re-charge after how long?

the charge drops and how many times do you need to charge it again before it damages the battery?

If the voltage drops then you have self-discharging cells and they aren't much good.

My latest batch of cells sat at 3.6v for over a year - no significant change in voltage. Maybe 3.61v -> 3.60v (hard to tell as such a small difference).
I have other cells from past battery builds - some 3-4 years sitting - and most are still 'around' the same 3.5v -3.7v when I left them for storage.

Voltage loss for healthy cells stored in reasonable temps at mid-range voltages is a slooooow moving process. Maybe others will comment with their experiences.

 

[cloudff7]

3,8v is good or bad for long term storage? is necessary put in 3,6v or 3,7v for preserve battery?

 

[italianuser]

3,8v is good or bad for long term storage? is necessary put in 3,6v or 3,7v for preserve battery?

@OffGridInTheCity answered that for you

 

[cloudff7]

Is there a universal charger for BM20 and BP-5L batteries? for loading and unloading to tensa storage

if I put these batteries to recharge several times at intervals of time to reach full charge, will these several times reduce the battery life differently if I put it 1 time and go to 100%?