ALLPOWERS20A Solar Charger Controller Solar Panel Battery Intelligent Regulator with USB Port Display 12V/24V

Oh boy, this is a good controller.I have a controller from Harbor Freight and there's no comparison.This controller is precise, accurate and smart. It's ideal if you want to charge a battery in the best way possible.It identifies what kind of battery you have and it provides the ideal voltage. It protects the battery from overcharge and it also has an optional feature that protects the battery from over depletion.Yes, I wish it had a couple of features that it doesn't have, but for $20, I have no complaints. This is real bargain.Here's what I wish it had:1. An instructional manual written in comprehensible English. You'll have to go on YouTube to see this thing demonstrated if you want to know how it works. But the good news is, the chances are you will not want to change the settings. The default settings are ideal for AGM batteries.2. The ability to use it without a battery. Why is this important? It's not. But if you connect it to a solar panel without the battery attached, you run the risk of ruining it. So long as you are sure you connect the battery first, you'll have no problem. And when you disconnect it from the system, disconnect the solar panel first. Just remember you'll never want the solar panel connected without the battery.I especially like the fact that I can glance at this controller and see the state of charge of my battery. I don't know of any other controllers that have this feature. It's a great feature and I wonder why it isn't even mentioned in the documentation. If you are in the habit of just checking voltage, that' a habit you should break.I was going to spend $50 on an amp hour meter but then I realized I don't have to because of this controller's feature.I don't see any controllers out there that are as good unless they cost more than $100.I'm quite impressed.

I have purchased five of these. I overloaded one of them (my fault) and damaged it beyond repair. I learned not to try to use one of these when they have been damaged, you can damage other components of your system by doing so. The rest have operated flawlessly charging a Lithium (LiFePO4) battery. I really like them other than the fact that they don't yet make a 30 amp model that supports Lithium batteries. I installed the first one back in 2019 so I have significant experience using them. Only one of them had a minor defect but was still usable. Fortunately it just happened to be the one that got burned up by overload because I had 400 watts of panels attached to it. I learned not to do that again. I have 300 watts of panels attached to the other ones and have not had a problem so far even though that is slightly over their capacity. I highly recommend these guys, they are relatively inexpensive work horses. I am using tw0 of them on 18v 20 amp dc power supplies for grid backup with no problems.

Pretty amazing for being the most affordable solar charge controller of decent quality. Was easy to install and is working as described in my van. Some little quirks like float volts can be set, but not equalize volts. Load on/off does not turn USB on/off. But just having USB, float volts setting, digital volts display; pretty amazing for the most affordable.4 stars because a simple common question arose during install and I could not get an answer from the manual, the support phone, or the support email. To improve it could include a more thorough and clear manual, and a prompt proper English response to support emails. The question was if it was okay to disconnect and reconnect the battery for days at a time, without disconnecting the panels. The manual mentions always connecting battery first, but also says the controller handles a low battery voltage, so not clear. Relevant to most RV installs, to know if panels need to be disconnected every time battery is.

PROS:* Inexpensive* Two USB ports* Display screen* 12v and 24v* Supports multiple battery types* Very customizable* D2D Dusk to dawn (unexpected feature I really like)CONS:* PWM Pulse Width Modulation rather then MPPT* Connectors are a little small (It will fit 10 Gauge wire but just barelyThis is a PWM controller but for the money you save buying this controller rather then an expensive MPPT controller you could buy an extra 100 watt solar panel. For instance a Renology 20 amp MPPT controller is around $100 more. My last 100 watt panel cost me $108 delivered. The more expensive MPPT controller might be a better choice if space is extremely limited and you need to squeeze out every watt. For the rest of us this is a pretty good choice.The display: It's not the worlds greatest screen and I wish it had a back light but I have terrible vision and I can still see it just fine. If you mount it somewhere dark bring a flashlight. The default screen shows battery voltage, battery level, and whether the battery is charging. Buttons scroll through other information like charging amps, load amps, temperature of controller, and optional settings.The USB ports: These are convenient. I have charged my phone with these ports quite a few times. They are rated to deliver 3 amps combined. You won't be fast charging with these ports but they work fine.12v / 24v: I won't go crazy explaining this but 24v can be better with long cable runs. I use 12v with short runs for convenience. This controller will do either. If you need 48v they make a controller that does that too.Supports multiple battery types: I use lead acid but you can also use Lithium Ion, and LIFePO4(Lithium Iron) For portable use Lithium Ion and LIFePO4 can save weight!Customizable: I won't go into every setting here but you can change things like cutoff voltage, charging voltage, low voltage reconnect, and turn short circuit protection on and off.D2D Dusk till dawn: I wasn't expecting this feature. This allows the controller to automatically turn on things like lights as soon as the sun goes down. If you want to set up outside lights this feature works great. I have been using this feature for solar night lights that actually work. This would be great for lighting a cabin, remote shed, or a long driveway.I was going to subtract a star because the manual didn't contain details on some advanced features but when I contacted the company they quickly responded with an updated copy of the manual. The updated version explained some features I previously didn't understand.