Using Solar Panels with Grecell Power Stations/Batteries
Do you have a portable power station/solar generator made by Grecell and would like to recharge it with solar panels?
In this article I am going to guide you through this and teach you what you need to know.
I will start by listing the different Grecell power stations, what their input port is, and what they’re rated at.
Related Product: I recommend the portable Coleman 100 Watt solar panel, it’s compatible with every Grecell power station and connects with the MC4 to DC adapter included by Grecell.
Since these type of power stations have built-in solar charge controllers, we need to find a solar panel that doesn’t. We don’t want to use two solar charge controllers.
The most important thing when choosing a panel is to make sure it’s compatible. That means not only do we need the right connector, but the voltage and amperage produced by the panel must be supported by the charge controller in the battery.
Grecell Power Stations – The Different Models And Their Inputs
Here are the different Grecell models, the input port they use, and the solar charge controller ratings. The links lead to the product page for the specific model on Amazon.com where you can see the current price.
I have done my best to research the information below, please let me know if you find an error or something incorrect.
- Grecell T300 – 8mm input port – 12-26V, 4A input ratings
- Grecell 300W/230Wh – 8mm & USB C input ports – DC: 11-24V, 5A – USB C: 5/9/12/15, 3A – 20V,5A 100W max
- Grecell P500 Mini – 8mm input port – 18-23V, max 80W
- Grecell T-500 – 8mm input port – 12-26V, max 105W
- Grecell T-1000 – 8mm input port – 12-26V, 8A max
- Grecell 2001A – Anderson Powerpole input – 11.5-50V
- Grecell 2200W/1126Wh – Anderson Powerpole input – 12-60V, 15A/600W max
- Grecell H2400 – Anderson Powerpole input – 12-75V, 800W max
Choosing A Solar Panel
There are a couple of things with the Grecell power stations that make it very easy and straightforward to choose a panel.
The input port
First, the input ports used are very common and most solar panels that include several different connectors often have either an 8mm or Anderson Powerpole connector included.
The 8mm connector is a little more common though, so if your Grecell battery uses the Anderson Powerpole you shouldn’t take for granted that the panel includes one.
The adapter included with all Grecell power stations
Second, all the batteries I listed above include what is called an MC4 to DC adapter. That adapter is for connecting solar panels.
Most larger and rigid solar panels use MC4 connectors, which include an MC4 male and an MC4 female.
Since Grecell includes this with all of its power stations, it’s easy to make the connection.
How about the voltage?
Now we just need to make sure the solar panel ratings are compatible with the solar charge controller ratings.
The voltage that matters is either the open circuit voltage (often referred to av VOC), and/or the optimum operating voltage (often referred to as VMP).
The solar panel we choose must output a voltage in the voltage range supported by the charge controller in the power station.
For example, this 100W solar panel by Renogy (click to view on Amazon) has a VMP of 20.4V. A quick look at the different input ratings I listed above tells me that the panel is compatible with all of the solar generators.
And, since the Renogy panel uses MC4 connectors, it’s ready to be connected with the MC4 to DC adapter included with every Grecell battery.
Solar charge controllers do have amperage limits, but these are okay to exceed to a certain point, and actually have to be exceeded to maximize the input. Since a 100W panel doesn’t actually produce 100W, we would have to connect 120-150W solar panels to reach an input limit of 100W, for example.
Solar Panel Recommendations
Now that we have the correct adapter and we know what to look for, we can start looking at solar panels.
Depending on the setup you have, you might want a portable, a flexible, or a rigid panel.
Grecell Solar Panels
Grecell makes and sells its own solar panels that are compatible with its power stations, here they are with links to Amazon:
- Grecell 80W Foldable Solar Panel
- Grecell 100W Portable Solar Panel
- Grecell 200W Portable Solar Panel
- Grecell 200W Pro Portable Solar Panel
All of the above are compatible right out of the box with all of the power stations.
Third Party Portable Panels
Here are a couple of panels that include different type of connectors, including the 8mm and Anderson Powerpole found on the Grecell products. The links lead to Amazon where you can see the current price.
- FlexSolar 60W – Comes with 8mm connector
- EcoFlow 60W – Uses MC4 connectors, so it’s compatible with all of the power stations since they include an MC4 to DC adapter
- Coleman 100 Watt – Uses MC4 connectors, so it’s compatible with all of the power stations since they include an MC4 to DC adapter
- Elecaenta 120W – Comes with both 8mm and Anderson Powerpole
- EBL 200W – Uses MC4 connectors, but also comes with adapter to connect 8mm and Anderson Powerpole
If you’re considering a different panel and isn’t sure whether it’s compatible or not, please leave a comment with a link to it and I’ll help you as soon as possible.
Third Party Rigid Panels
Here are a couple of more rigid panels that are great for more permanent installations and setups. All of these come with MC4 connectors so they’re ready to be connected right out of the box. They’re also compatible voltage-wise.
If you would like to extend the cable between the panel and the input port, check out the “Extension cables” section further down in the article.
The rigid panels above can withstand rain and snow. They have waterproof junction boxes, and MC4 connectors are usually rated IP67 which means they can also handle water.
Combining Panels
The Grecell 100W panel includes a Y branch which makes it easy to connect two of them in parallel to create a 200W setup.
If that’s something you would like to do but don’t have a Y branch, I recommend the Linkpal Y Branch (click to view on Amazon).
A parallel connection will combine the amperage but keep the voltage the same, that’s the only supported way to combine panels with the T-500 and smaller since their max input voltage is below what two panels combined in series would output.
The T-1000 and larger support combining two 12V panels in series in addition to parallel, which means that you don’t need a Y branch. Then you simply take the positive MC4 connector from one panel and connect it to the negative MC4 connector on the second panel.
That’s going to combine the voltages but keep the amperage the same.
From there, you’ll just need to connect the remaining two MC4 connectors (one from each panel) to the MC4 to DC adapter and connect it to the input port. Again, this is only compatible with the T-1000 and larger, and you still need to make sure that the two VMP voltages combined won’t exceed the input voltage limit I listed earlier.
Extension Cables
If you’re using solar panels with MC4 connectors, I recommend the Geosiry Twin Wire solar panel extension cables (click to view on Amazon).
They’re available in different lengths, and are 10 AWG, which supports at least 30A, usually more. Check the specifications of the specific length and AWG you purchase to make sure it can handle the total amperage output by your panel(s).
Frequently Asked Questions
Can I use a solar panel when it’s cloudy? Rainy?
It depends on what time of the year it is, where you are, and how cloudy it is. In the summer they can definitely produce some watts even on cloudy days, but in the winter it’s not bringing out a panel in my opinion (at least in the north where I live).
If the panel is waterproof and has waterproof connectors, it’s fine to leave it out in the rain as well.
Power stations are not waterproof though and should always be used in a dry area.
How long is it going to take to recharge my battery with a solar panel?
It depends on a lot of things. The size of the battery, current state of charge, the solar panel, its efficiency, sun and weather conditions, among other things.
Based on my own experience, on a sunny day in the middle of the summer, a 100W solar angled toward the sun will generate between 300-600Wh. So if you have a power station with 230Wh, it should be fully charged in a half day of sunshine.
What can I do to improve the charging speed with solar?
You’re always going to be limited by what the solar charge controller in the battery can handle and at the speed it can transfer the generated electricity to the battery.
If you’re not near the input watt limit, you should make sure the panel is clean, directly angled towards the sunshine, and that there is nothing in the way of the panel. Even a small shadow can decrease the efficiency of a panel significantly.
You should also try to use the shortest connection possible, meaning that a long extension cable is going to cause a lot of power loss. If you have to place your panel far away from the power station, you should get purchase more panels and if possible combine them in series to increase the voltage.
Please leave a comment if you have questions.