Battery design of radar tester

September 13, 2022
Latest company case about Battery design of radar tester

1、 Requirements for standby power supply of GPR tester:


GPR tester has the requirements of high working voltage, long time and special environment temperature. In terms of lithium battery cell, bick long-life lithium battery cell of first-line brand in China is used, and 6 series of 8 parallel combinations are used to meet the customer's relevant parameter requirements. In the protection of lithium battery protection circuit, 6 series of precision hardware protection circuit + 6 series of charging balance circuit are used to achieve the requirements of maximum overcurrent 25A, continuous discharge current 8a and charging balance current 300mA of finished lithium battery. In terms of relevant working environment, high-grade white waterproof box shell is used to meet the waterproof environment requirements of customers. The specific parameters of the combined battery are as follows:

1) Model design requirements of lithium battery pack: 18650-6s8p / 16ah / 22.2v.

2) Design requirements of circuit part:

1. Single section overcharge protection voltage: 4.35 ± 0.25V

2. Single overcharge recovery voltage: 4.15 ± 0.50v

3. Single section over discharge protection voltage: 2.70 ± 0.08v

4. Single overdischarge recovery voltage: 3.00 ± 0.10v

5. Overcurrent protection value of combined battery (10ms): 30 ~ 35A

6. Charge balance current: 300 ± 50mA

7. Charge balance voltage: 4.20 ± 25mV

8. Battery over temperature protection value (recoverable): 70 ± 5 degrees

9. The finished battery also has short circuit and reverse charging protection.

3) Design requirements for battery cycle life: 500-1000 times (GB charging and discharging standard)

4) External dimension design requirements of battery: reference shell

2、 Design scheme of standby power supply for GPR tester:

1) Protection board (PCM): it is mainly a protection circuit designed for rechargeable lithium battery. Due to the chemical characteristics of lithium battery, it is necessary to provide intelligent power calculation, overcharge, overdischarge, short circuit, overcurrent and other protection functions to avoid combustion, explosion and other hazards.

2) Protection IC: the main protection function chip of the design scheme, which can monitor the overcharge, overdischarge, overcurrent, short circuit and other functions of the electric core on-line and at all times, so as to make the electric core work in a safe, stable and efficient range.

3) Charge balance module: balance the voltage difference of each cell during the charging process, enhance the consistency of each cell voltage to extend the service life of the combined battery.

4) Temperature switch: mainly designed for temperature protection function. When the temperature of the battery itself reaches 75 ℃ due to other abnormal problems, the temperature switch acts to achieve over temperature protection, and when the temperature drops, it will automatically recover.

5) 18650 lithium ion cell / 18650 / 2000mAh / 3.7V bak cell (long life cell).

6) MOSFET: MOSFET, which plays a switching role in the protection circuit. It will never increase or decrease the voltage at both ends of the load, so as to ensure the voltage stability.
3、 Schematic design of standby power supply for GPR tester

4、 Standby power supply and realization diagram of ground radar tester