Hello everyone,
I'm gearing up for potential winter blackouts and I'm looking for advice on how to quickly charge large LFP (Lithium Iron Phosphate) batteries during limited electricity availability. There's a chance we might only have electricity for 2 hours per day, so I need to maximize charging during that window.
My Setups:
Possible Solutions I'm Considering:
Solution 1: High-Voltage DC Power Supply via MPPT Input
Use a high-voltage (HV) isolated DC power supply capable of delivering ~140V+ DC or higher to provide power through the MPPT (Maximum Power Point Tracking) input of the inverter.
Use a high-current, low-voltage DC power supply to charge the batteries directly, in parallel with the inverter. The DC power supply voltage would be set to the battery's bulk charge voltage. As the battery approaches 90% SOC, the power supply's output naturally tapers off, and the inverter handles the rest of the charging process.
Solution 3: High-Voltage DC Power Supply with External MPPT Charge Controllers
Use a high-voltage (75V to 110V DC or higher) isolated power supply in conjunction with external MPPT charge controllers (e.g., Victron SmartSolar MPPT 100V Charge Controller) connected directly to the batteries. This setup is separate from the inverter's high-voltage power rails.
My concerns are:
I'm open to any advice, suggestions, or recommendations you might have. My main goal is to ensure that the batteries can be safely and efficiently charged during short periods of grid availability.
Thank you in advance for your help!
I'm gearing up for potential winter blackouts and I'm looking for advice on how to quickly charge large LFP (Lithium Iron Phosphate) batteries during limited electricity availability. There's a chance we might only have electricity for 2 hours per day, so I need to maximize charging during that window.
My Setups:
- (P1) 48V LFP (16*EVE280Ah) battery attached to a 5kW solar hybrid inverter (max 80A or 60A AC charge input).
- (P2) Two 24V LFP (8*EVE280Ah, 8*EVE305Ah)
- batteries, each attached to a 2.4kW solar hybrid inverter (max 60A or 40A AC charge input). (these two are going to my friends)
Possible Solutions I'm Considering:
Solution 1: High-Voltage DC Power Supply via MPPT Input
Use a high-voltage (HV) isolated DC power supply capable of delivering ~140V+ DC or higher to provide power through the MPPT (Maximum Power Point Tracking) input of the inverter.
- Pros:
- Utilizes existing inverter infrastructure.
- Potentially high efficiency due to MPPT optimization.
- Cons:
- Requires a reliable and safe HV DC power supply.
- Safety concerns with feeding power into the MPPT input not originally designed for grid charging.
Use a high-current, low-voltage DC power supply to charge the batteries directly, in parallel with the inverter. The DC power supply voltage would be set to the battery's bulk charge voltage. As the battery approaches 90% SOC, the power supply's output naturally tapers off, and the inverter handles the rest of the charging process.
Solution 3: High-Voltage DC Power Supply with External MPPT Charge Controllers
Use a high-voltage (75V to 110V DC or higher) isolated power supply in conjunction with external MPPT charge controllers (e.g., Victron SmartSolar MPPT 100V Charge Controller) connected directly to the batteries. This setup is separate from the inverter's high-voltage power rails.
My concerns are:
- (q1) Which of these solutions is the most realistic and safe for quickly charging my LFP batteries?
- (q2) Are there better or more efficient methods to achieve fast charging within a limited time frame?
- (q3) What are the potential risks or challenges associated with each solution, and how can they be mitigated?
- (q4) Has anyone implemented a similar setup? I'd appreciate hearing about your experiences and any lessons learned.
I'm open to any advice, suggestions, or recommendations you might have. My main goal is to ensure that the batteries can be safely and efficiently charged during short periods of grid availability.
Thank you in advance for your help!
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