I now have a new solar installation. Well, it has been a few years since foray into solar power in 2021. Back then, 12-volt panels were the norm. Now, they are shy of 600 watts and 50 volts. Solar panels now taller than an average person and weigh around 30 kilos.
The cheapest panel were from Waree but they were selling in pairs or higher combinations. Sometimes, they ran sponsored deals that had two 400-watt mono panels selling for ₹14,000. Slightly higher rated panels from other manufacturers were selling for the same price on a per-unit basis so it was a good deal. I had some misgivings about the panels. Some online reviews complained of poor current output. In addition, the courier company had spilled battery acid on the package.
For the inverter, I went for Hykon Solis model with a 50-AH lithium battery. (Hykon is a Kerala-based company and the first one in India to create a Lithium inverte.) I just needed it as a solar charger for my 100-AH Stalwart Solar Omega power inverter. Hykon sales personnel gave me a Christmas offer for the Helios-brand inverter with a 100 AH built-in battery and that it had updated software. I took the offer. Hykon Helios 1000 model could accommodate 1000-watt PV (solar) input. Its PV charger was rated 50 amperes maximum.
The Waree panels were rated at 40 volts and 11 amperes so the 800 watts generated at 22 amperes should have been fine. Nope!
I live in North-central Kerala. In non-rainy seasons, the sky is very cloudless. There is continuously bright sunlight and heat. From 10:30 am to 2:30, the panels seem to generate high voltage or amps or the MPPT algorithm of the inverter reports so. I do not have a clamp multimeter that can measure DC current. The inverter stops charging when the current goes above 40 amps at 40 volts, that is 1600 watts. The inverter's limit is 1000 watts. The panels were supposed to generate only 800 watts.
I had to add a circuit breaker to idle one of the solar panels. The other panel generates 25 to 28 amperes during the middle of the day.
On rainy or cloudy days and in the mornings/evenings, both panels could work together. I have to be around the installation to turn on/off the circuit break as it is rated at 32 amperes. I will replace it with a 25-amp breaker in the future so that the system is semi-automatic. Of course, in the evenings or on cloudy/rainy days, the breaker will not magically turn on.
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UPDATE (1 March 2025): I replaced the 32A breaker with a 25A breaker but it would not trip before the inverter reported high current. Later, I replaced the 25A breaker with a 20A breaker but it would not trip either before the inverter. Now, I wonder what is happening. Is the inverter generating very high voltage and the MPPT algorithm bucks the voltage and boosts the amps?
UPDATE (June 2025): I finally got a clamp multimeter. The panels generate 10 amps each. They function as per spec. The inverter does not report the incoming current or voltage. Using its MPPT algorithm, it decreases the voltage and increases the current. It was this that resulted in the inflated rating of up to 48 amps. When the panel current goes above 13A or the inverter reports current above 48 amps, the inverter reports an error state and stops charging. Another problem that the inverter has is that it turns off when the battery becomes fully charged from solar. It will do this even loads are connected. I have to manually turn it on again.