---
# System prepended metadata

title: Li-ion 18650 充電效率-溫度實驗
tags: [Project, Satellite, CubeSat, battery]

---

---
###### tags: `CubeSat` `Satellite` `battery` `Project`
---
# Li-ion 18650 充電效率-溫度實驗

## 預期目標：Smart Charging Satellite
* 得到最佳充電狀態數據
* 完成電池恆溫PID算法
* 完整計算+Plot的python code：input csv ---> Output best temperature, figure
## 流程
1. Plot內電阻-充電效率-溫度關係
2. PID恆溫調參

### Plot內電阻-充電效率-溫度關係
* $Max(CC) = Full Charged$
* 了解電池性質：溫度、充電功率上限、下限
* 放在chamber中從$for i in range(0,82,4)$ ---> 縮小範圍$for j in range（X,Y,2^(3-time))$
* 用兩組電池分別充放電測試
* Matplotlib自動繪圖
* Ternary Search code Maximum charge effectiveness value

### [Python PID](https://pypi.org/project/simple-pid/)
```python=
from simple_pid import PID
pid = PID(1, 0.1, 0.05, setpoint=1)

# assume we have a system we want to control in controlled_system
v = controlled_system.update(0)

while True:
    # compute new ouput from the PID according to the systems current value
    control = pid(v)

    # feed the PID output to the system and get its current value
    v = controlled_system.update(control)
```
## 實驗記錄
### 10/22
* FOR charging: CC ---> CV(cc=constant current cv=constant voltage)
* 由內電阻知電池壽命 is a unknown barrier
* 我們有內電阻測量工具
* 一組有兩顆電池並連
* 把電池外皮剝掉，貼上黃色防靜電交帶，再用銅箔包覆以平均加溫
* For 18650：3.7V是標稱電壓，Full Charged是4.2V
### $C=充放電電流/額定容量$

Ex: 額定容量為100Ah的電池用20A放電時，其放電倍率為0.2C

### Capacity Retention
存放一定時間後，在指定的放電條件下可從電池獲得的下降容量的分數。