[Upgraded]30A MPPT Solar Charge Controller 12V/24V Auto Focus MPPT Tracking Charge Controller with Bluetooth LCD Display Dual USB Solar Panel Regulator, Timer Setting, Multiple Load Control Modes

Good solar-panel charge & load controller. Automatically senses if the solar-panels are for a 12V battery or for a 24V battery system (electrical knowledge is required).

The app setup is not English friendly. Some steps on app download screen are in Chinese, so I luckily guessed which option to click. I was unable to scan provided QR code to set up Bluetooth. When I scanned QR I received a message of "This QR code doesn't exist". And the manual QR code was the same. I'm sending this back.

instructions in no better words then suck's.

This may or may not be an mppt solar charge controller. I believe seller is using MPPT as a brand name and not actually the way it functions as a charger. I believe it's a PWM charger but I have no way of testing it to confirm one way or the other. I bought it as my spare. Do your own research.

Works with 4 100w panels and see.s to do what's it's supposed to but the instructions are poor

This little MPPT charge controller works fine as someone who is use these in the past I would recommend you read the instructions, so you know what to plug-in first. If this is not installed correctly, it will pop and be worthless. Once connected and working, it works great.

I was excited at the possibility of a low cost MPPT charge controller. Sadly, this is a fraudulently labeled and advertised controller - something you might expect on AliExpress. The circuitry inside is purely PWM. Correctly labeled PWM controllers exactly like this cost less than $15 for - so you are NOT saving money. Because this is a PWM controller, if your panel voltage does not match your battery voltage - you will lose all power in the excess panel voltage. DANGER! Worse than fraudulent - it is advertised as a 100 amp controller. This PWM controller is not capable of 100amps and will cause a fire long before it reaches 50amps. Those tiny little transistors have a shoddy pressure contact to the cheap and unventilated metal backplate. Shame on the seller and shame on Amazon. Do not buy!

I got the 12/24V model (the manual shows one capable of 36, 48, and 60V systems is out there). For many controllers with the "MPPT" title they can accept power like 76V 5A input (created from 4 panels wired in series) and "transform" that power to something like ~14V 25A battery charge. They say in the manual for this "Max solar input 18V for 12V system, or 36V for 24V system" showing it can't do the above "transforming" that you may want in a controller. Seeing the price of this compared to others that can do such transforming it's not surprising to me that it can't do that. I even wonder if the "Max 18V for 12V system" means a panel with 22V open circuit power (which many panels will have) is unacceptable? They may mean ~18V (not that 18.5V is too high), but we need better details to know for sure. Otherwise it is a controller to prevent overcharging a battery (where many solar panel can go to 18V+, yet all 12V batteries should never go above ~14.5V).Another item I'll bring up is the manual points out "Always connect the battery first and solar panels secondly, reversing that order when disconnecting" (which is common for most controllers). Many of the newer lithium batteries come with the built-in "Battery maintenance system" or BMS controllers that will block power when it sees the battery is full. That sudden disconnect of the battery by it's BMS controller has the potential to fry any controller from the disconnect due to that "incorrect order". I've tried to contact multiple battery OEMs asking about this concern, but they've ignored me (yet answered other Q&A). So beware that possible situation. I've thought myself "I can keep an older lead acid battery in parallel with the other to keep something connected if the BMS blocks it", yet many respond "You don't want a mix of batteries like that wired together". You can also set the max charge voltage well below where the BMS cuts out, but then you're only charging it 80% or such (taking away some of the battery capacity). So not sure what a good solution is to this dilemma (which isn't just about this product).