# BMS for Li-Ion Batteries
**URL:** https://community.electricforum.com/t/bms-for-li-ion-batteries/16222
**Category:** Uncategorized
**Created:** [June 4, 2019, 11:58pm UTC](https://community.electricforum.com/t/bms-for-li-ion-batteries/16222 "2019-06-04T23:58:39Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@haiescalade](https://community.electricforum.com/u/haiescalade)
#### Post date: [June 4, 2019, 11:58pm UTC](https://community.electricforum.com/t/bms-for-li-ion-batteries/16222/1 "2019-06-04T23:58:39Z")
Some BMS for Li-Ion batteries control the SOC battery 20%-80%. I bought a BMS from Aliexpress model JBD-SP15S001 use for my Li-ion battery. I heard BMS will control the SOC for the battery. When I fully charge the battery, the LCD read 100%. Does it mean the battery only 80% full (because BMS prevent the battery charge to 100% to prolong the life of battery). Same thing when I discharge the battery , LCD show 0%. Does it mean the battery has no more juice ? Does it mean 0% or still has 20% to prolong the life of battery ?
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### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [June 5, 2019, 12:04am UTC](https://community.electricforum.com/t/bms-for-li-ion-batteries/16222/2 "2019-06-05T00:04:54Z")
SOC reading is generally of little value.
Cell voltage tells all on most chemistries. Exception being LiFePo4 which holds the same voltage through a large range.
If you post details and pictures, you will get lots of help.
It seems you may have some misinformation already.