Hi TI,
I’m working on an application consist of parallel connected 2 solar panels and AC to DC adapter as input, 2 bq24650 on a single PCB, and 2 LiFePO4 Battery packs to charge. Additionally, 5Vdc, 12Vdc, and 24Vdc output to load.
Belows are some details of components.
1. Solar panels:
-Vmp: 18.5v, Imp: ~8A, Voc: 21.8V
- Two solar panels are parallel and have different angles to face the sun. Voltage and amperage of each solar panel at the time of power generation are different.
- One solar panel always connects with and adds another solar panel by demand of power to harvest.
2. AC to DC Adapter
-Voltage is between 20V and 24V and amperage is less 8A
3. Bq24650
- Two bq24650 are parallel and coupled with each solar panel.
4. LiFePO4 Battery Pack
- 4SnP combination having 12.8V, 40Ah, 8A as standard charge current, 20A as max charge current, 30A as standard discharge current, and BMS.
- Two battery packs are parallel. One battery pack always connects with and adds another battery pack by demand of power of the load. (cost is always matters.)
A bit wordy explanation since I am not familiar with solar things. My inquiries are as follows.
1. What are the cautious things I have to consider to design this application about each functioning blocks of the application mentioned above?
2. Previously, I tested to charge 12.8V LiFePO4 by DC power supply 24Vdc, 10A instead of a solar panel using previously developed application which has single bq24650 set to an 18.5V solar panel. The DC power supply enters CV mode and amperage drops to 5.3A. It terminates charging because of heat after a couple of hours. This test showed that heat management is critical. Do I have to lower Amperage of the adapter? If so, which level of amperage might be good?
Would you recommend AC to DC adapters with regard to voltage, amperage and other specification of it?
If there are any things to explain in depth for you to understand my inquiry, let me know then I’ll give you more details
Regards,
Jeong, Jake.
