1: What is the difference between PWM inverter and MPPT inverter

Answer: PWM is Pulse width modulation, it is a old solar power controller technology,  its efficiency is about 70%

MPPT is Maximum Power Point Tracking, it is the latest technology. it contains Low Voltage and High Voltage, 2 types.   High voltage inverter efficiency up to 95%

2: How to distinguish Low voltage and high voltage inverter 

Answer : Low voltage, Max PV voltage Voc < 150V.    High voltage, Max PV voltage Voc > 450V

3: Sometimes products description writes MPPT inverter 3000W and MPPT 4KW,  it is confusing, 

why write 3000W and 4000W , is it contradictious

Answer :  3000W means inverter support Max load 3000W, (TV, laptop, airconditioner, fridge etc). 

MPPT 4KW is MPPT controller, it can abstract 4000W power from solar panel,  supply power to appliances and supply power to battery at the same time.  Battery charge power +  Load,  together up to 4000W

4: During day time,  power supply to load,  does it come from battery to solar power.

Day time there is enough solar power,  Appliance powered directly by solar power,  and battery get fully charged and stand-by mode.   Night time solar power gone, Battery get activated and start to supply power to appliances

Or during cloudy day, solar power is weak and not enough, battery work as auxiliary power.

5: Do you accept OEM / ODM

YES, we accept OEM/ODM. Both software and hardware,  need to disguss details to finalize accept or not.

6: If we want to print our company Logo on products, how many pcs as MOQ to start.

YES, we do laser Logo print for customer,  MOQ starts from 10pcs,  customer need to pay for the extra logo print cost.    If customer order accumulately up to 100 units, we refund logo print fee