Darknight

I have the 3kv Growatt inverter. A friend of mine got the 5kv one. I've had mine installed for about 2 weeks now. As far as the inverter itself, for the 2 weeks I've had it running, it's run decently well. Installing the inverter was relatively simple as well (according to my installer). The inverter readings are easy to navigate and gives you quite a bit of information, however, you won't find a lot of information about your solar panels such as how much power they're generating. The negatives for me are that the inverter can be quite loud. Also, my inverter came with a USB cable and some desktop monitoring software that is extremely buggy. I would recommend if you want monitoring capabilities to get the WiFi attachment. Apart from these minor gripes, I'm pretty happy with it.

I'm all the way in Zim. The panels I have are the HiKu panels with the line divider in the middle of the panel. How much are you selling yours for?

Awesome. I'll hopefully be able to get another panel within the next week or so. My current panels are canadian solar 330w. I'm going to try and get the fourth panel from the same supplier but if they're out of stock, I'll have to go with another supplier who has canadian solar panels, but his are 385w if I'm not mistaken. I'll post an update once I've got the panel installed etc. Thanks everybody for the help.

The VOC (NMOT) rating of the panels is 36.7v. In the case that I'm not able to get the exact same panel for the fourth panel, I was told by my electrician that I should get a higher wattage panel. Is this correct and would I still be able to wire this higher output panel with the existing 3rd panel in series? So, just to wrap my head around this, if I have 2 pairs of 2 panels wired in series that would make each pairs output (at a rating of about 36.7v per panel) equal to about 73.4v and 8.73a. These two pairs of panels would be then be joined in parallel with an output of 73.4v and 17.46a. Is my math correct? It hardly gets that cold in winter. In fact this winter was probably the warmest winter in a few years. I'd say the minimum I've ever seen the temperature drop to is probably 2 degrees Celsius.

Sorry, didn't see this part. From what I've seen from the readings on the inverter screen, my input pv voltage from the panels during the day is is usually between 31v and 35v. When the mppt draws current from the panels, does that reduce voltage? By wiring the panels in series, that would increase my voltage but leave my amperage the same. Each panel has a Vmp of 29.4v (NOCT) and an imp of 8.34a (NOCT). If I wire the panels in series won't I be restricting how many panels I can run because the max pv input on the inverter is 102vdc and by wiring my 3 panels in series my voltage would already be 88.2v? Do you think adding another panel, while keeping the panels wired in parallel (or series-parallel) would prevent the mppt from switching off after drawing current? Or should I just try to add more load to the inverter during the day?

So after browsing another board on this site, I came upon this post. Sounds a bit like a reason for why my solar input is constantly jumping up and down. I may not be putting enough load on the inverter which is causing the mppt to discard the excess output from the panels. Not sure if that makes any sense. Would anyone be able to back that up? What I have also noticed is that when the battery bank is fully charged, and the grid is powering the load during the day, the solar feed to the battery will be constant.

Sorry, please could you explain that a bit more. If the system is trying to take all it can from the panels wouldn't that mean the solar wouldn't be jumping from 0w to anywhere between 115w and 380w and then back down to 0w every couple of seconds?

All 3 panels are connected in parallel. The 2 x narada 12v batteries are connected in series. The strange thing about these inverters is that the spec sheet differs with the manual for certain settings. The spec sheet for the inverter shows that the maximum solar charge current is 50a. The manual for the inverter states the max charging current is 80a. Maybe they're two different settings. The manual states that the setting for max charging current is the total charging current for solar and utility chargers (max charging current = utility charging current + solar charging current). The max utility charging current is set at 20a which is why the max charging current setting is so high (because it includes the max utility charging current value). Would you recommend setting the max charging current to 50a or 45a? Do you think this setting might be a cause of why the solar output is constantly jumping during the day? I'm a complete noob at this, so for all I know, the constant jumping of solar output might be normal and correct. I wouldn't really know. I have a video of the inverter screen if that helps to explain what I'm querying.

Thanks for the help. Appreciate it. The original max charging current was set at 60a so maybe I should drop it back to that or maybe even drop it down to 50a. My bulk charging voltage is set at 28.2v. Thats the default setting on the inverter. The float voltage is at 27v which is also the default setting. The sticker on the battery states that the float is 2.25vpc so the setting checks out to be correct.

I got the tv about 8 years ago lol. It's been good to me. So according to the sticker on the inverter, the max pv input voltage is 102vdc. I'm not sure where to find the min pv input. I've set the maximum charging current to 70a based off a formula I found online. Basically 990w / 24 = 41.25 * 20% (for reflection etc) = 51.56. The inverter manual says the maximum charging current should include the maximum utility charging current. So 51.56 + 20 = 71.56. Do you think I should set it to 75a or should I lower it? As far as the pv output wattage I've seen, it varies between 115w and 380w. So it's constantly jumping between 0w and anything between 115w and 380w before dropping to 0w every 10 to 20 seconds. This constant jumping only occurs when solar is available during the day.

The wattage rating on the sticker on the plasma is 410w though I have energy saving enabled on the tv so I'm sure it's probably approximately 300w or so. The panels are facing north. I have a flat roof on a double story house and the panels are mounted at an angle. The inverter is downstairs so I had to run about 25 meters of solar cable from the roof to where the inverter is placed. Not sure if that makes any difference. Also, the panels are wired in parallel. As far as the weather, it's been very hot with no cloud cover for the last week. There is no shade on the roof during the day. The load on the inverter is very low even with the TV and freezer on. It only hits about 20% load. So I'm thinking it might be something to do with how the mppt is controlling the voltages in regard to the load required. Do you think that could be the case for the panels constantly cycling between 0w and approximately 350w and back down to 0w every 10 to 20 seconds?

Hi all. So about a week ago, I got my solar system up and running. I'm running a growatt 3kv 24v inverter with inbuilt mppt. I have 2 x narada 200ah 12v batteries and I have 3 x 330w solar panels. I have a few questions that I'm hoping someone here could help me with. Firstly, some background info. The inverter is powering 1 x plasma TV (I know I need to get an LED), 1 x small freezer (186w), and a few led lights and a few sockets used for charging phones, router etc. If I have no power after 4.30pm, I will switch off the freezer to prevent it being powered by the battery without solar energy to keep the battery charged. I've set my inverter output priority to utility first and my charging priority to solar first. My thinking behind these settings is that I want to make sure that during the day, if I have grid power available, solar is dedicated to charging my battery while the grid power is used to power the loads. On the other hand, when solar is not available in the evening, if I have grid power available, it can charge the batteries as well. Either way, I'm trying to make sure that my batteries are fully charged as often as possible considering that I experience load shedding of between 8-12 hours a day every day. So thats the background info. Here's what I've noticed and what I require some assistance with... 1. I've noticed that if I have no grid power during the day, solar will charge my battery and supply load. The weird thing is that according to the monitoring software for the inverter, and the inverter display screen, the solar output isn't constant. It's continuously jumping from 0w to 350w and then back to 0w every 10-20 seconds. This occurs whether or not the TV or freezer are on. Is this normal? I was under the assumption that the solar output would be constant. 2. I've noticed that if I have grid power available during the day, the solar output isn't constant as explained in question 1. However, when the solar output drops from 350w to 0w, the grid power will charge the battery until the solar output kicks back in. The charge priority settings state that solar energy will be prioritized if solar is available and if it isn't available, utility power will be used. I was under the assumption that, based off the output priority settings and charge priority settings, if the grid power is available and powering the loads, solar would be dedicated to charging the battery. Are my assumptions incorrect? I would appreciate any assistance and I am happy to provide more information if necessary. Thanks.