Connected this MPPT controller to my 400watt solar panel and my 200ah lithium battery. No issues with overcharging. No issues with excessive heat coming off the controller. Has been working perfectly. Was easy to configure and connect to both the panels and the battery.

At $80 this MPPT Solar Charge controller isn't terrible, but given it seems to be some generic components thrown together, isn't great. At half the price it would be a great deal. It does offer usb output, which is good to see. If you need 12/24V flexibility or USB output, this would be worth trying, otherwise I'd look for something either more reliable and better documented, or cheaper.

The charging algorithm for this unit is clearly not suitable for lifepo4 or lithium batteries, with no current based limiting/charge cutoff. It will always try to 'float' batteries, which is going to substantially impact the lifespan of lithium based chemistries. Seems to be fine for SLA or leadacid, so it's been relegated to use on my camper.. for now (until i update it to LiFePo4.)

I’ve wanted to expand my solar shed environment for a while, but have been using a relatively small (8.5A) Pulse Width Modulation (PWM) solar charge controller that couldn’t handle more solar input. With this 40A Maximum Power Point Tracking (MPPT) controller, I’m hoping I’ll get more efficiency out of my current panel, and now have the option of adding more panels. With the 100v maximum solar input, I can also add panels in series, increasing the voltage and reducing the need for heavier gauge wires (higher voltage, less current for the same power input.)The Solar Charge Controller arrived securely packed in its box, with an instruction manual and nice cardboard installation guide template to get the four hanging holes properly lined up for mounting the controller. The controller is physically bigger than I was expecting (since I’m replacing a relatively tiny 8.5A controller.The User Manual states that it is version 2.1, and that you should contact customer service personnel for the latest version information. Interestingly enough, there is NO actual mention of how to contact customer service. In fact, there’s not even any information on the company that makes this charge controller, so it might be hard to find out about new versions. Then again, since this controller does not (appear to) connect to any networks, I’m not sure how you’d upgrade any firmware in it (perhaps via the USB ports on the bottom?)I like the built-in wire clamp connections in the bottom, with tightening screws hidden behind the flip-down cover on the bottom front of the unit. It keeps it looking neat, while making connections easy. The connections are large enough for heavy gauge (4 AWG or maybe larger) wires if needed. The display is sharp and clear, although it would be nice if it had a backlight. The descriptive sticker on the box includes the words “with Blacklight LCD Display”, which I was taking to mean it had a “Backlight” display, but the manual makes no mention of a display backlight, and the setup menu only allows a few choices (battery type, load on time, and custom charge parameter settings (for those that know/need specialized settings.)For testing purposes, I wanted to temporarily connect this to my solar shed battery, but with the wiring connections coming out the bottom, you can’t just stand it up on the workbench. You can lay it on its side or back, but neither is ideal for air flow to the large aluminum heat sink fins on the back of the unit. If you’re going to be pushing this to the power limits, you might need to worry about keeping it upright (mounted vertically), but on a cloudy January day in the PNW, with my limited solar panel input, overheating is not a real concern.So, it seems like a nice charge controller, but the User Manual just covers the bare minimum you need to hook it up. You’re going to be on your own figuring out what charging mode it’s using based on your battery charge level. Also, there are several mistakes in the manual, like telling you to mount it “where water can easily enter” (there’s a missing “no” as it’s not waterproof), and a diagram showing the air flowing from top to bottom with the hot air exiting at the bottom (it seems like for convective reasons alone, the fans should be blowing upward the way the air would naturally flow - though I didn’t push the unit hard enough to turn on the fans.)Actual rating: 4.25 (for documentary reasons, including how to turn on any backlight.)

Just in time for limited sunlight. I have three small sections of panels at different angles. Two of my portions have the updated function that this new controller provides... replacing the third because the unit does not shut down when the panel current is too low.... consumes power when not charging. This has been a concern when the daylight gets short and the winter storms close in.Installed immediately, appreciate the technical features for preserving charge. Nice size.. Half of the older style of the same amperage. interesting this unit comes with color options.

So far so good. Photo shows it in use in late January in South Dakota in late afternoon sun. The panels were nearly vertical to face the sun and it was just starting to drop behind my trees so the current was dropping as well. A few minutes earlier the charge current was over 15 amps. I’ll be using this for portable amateur radio operation in the spring once the weather warms up. I don’t know yet how much RFI this charge controller produces.

I used this on my small system, replacing a 15 amp controller. It reads 1.1 amps less now. The old controller is small and was cheap, but seems to work better. Going back to original

The manual doesn't list much to help me configure the solar panels in series or parallel. Or how to get the correct USB dongle for the controller to have a remote screen or bluetooth added. So it is missing features other MPPT chargers offer. For now i have them in series, four 100W panels. My main issue is even when my LiFePo4 battery is full, its still dumping some voltage into it. That wouldn't be a problem if I had a constant draw on my battery. But i don't. So I removed this and opted for a 30amp Victron with Bluetooth. Its probably fine for anyone using SLA batteries who also has a small draw on them to prevent overcharging.