This device has told me where they were problems in the past with other similar devices with pulse with modulated devices with my solar panels and even with bad connections and you're not going to get that level of technical aptitude and given an English manual for the most part with other charge controllers. The functions are limited and what it can show and do but for what it does, it does it well. Rich solar has never disappointed me except maybe on the price of their panels for competing products. Make sure your wires connect well and try not to disconnect them repeatedly, you will catch yourself off guard and this thing will think it's sleeping.. and the sun's out. I've not had a single problem with thisThis is a newer brand of a well known manufacturer that also makes the Renogy Rover. The Bluetooth BT-1 module works along with the Renogy app. The problem I found and also in some research is the Boost has no options to disable it. Others models call generally call it Bulk and absorption. This model calls it Charge and Boost. For Lithium charging it should shut off when it reaches the charge voltage usually around 14.4v for a 12v nominal battery. This model will just sit in the Boost voltage for hours at the higher voltage cuz that's what lead batteries like. The only option to shorten the Boost time is buy the BT-1 Bluetooth module and use the App to get to the Boost duration setting. It's a well known issue, that requires more money.The Lithium settings should allow disable or change the Boost duration called absorption on most controllers. Should be around 10-15min for most Lithium but check your specs. Otherwise it's a decent all around unit although the display should have a light and Bluetooth included. HQST has a 40a M2440N with Bluetooth built in for A LOT less...it's a good option with Boost customizable in the USE settings not LI. The HQST is about $65 less for the same options.I bought this Rich solar charge controller for my 12 V 100A LIFEPO4 battery and I like the size, shape, quality, performance especially negative and positive where battery wire connect to are good and solid. the price is not too expansive.I like the display and it is easy to adjust settings. Manual is easy to read.This is my second charge controller I have purchased for my own use, it has MPPT support which I like with a serial port and temp sensor plug with capability to upgrade to use bluetooth using a BT-1 module. Where the problem starts the temperature plug wont stay latched in and I don't seem to get any temperature readings even if when I hold it in, apparently looking at other reviews this seems to be a common occurance. I purchased a Chins 100AH LiFePo4 battery and I have to go into user mode to set the parameters but the general LiFePo4 parameters don't match what the Chins battery is specifiying charge limits to be, and finally most other charge controllers have a usb port, this particular issue is on me though as I should have noticed that before purchase. If you don't need a temperature probe and have normal batteries like lead acid than this a decent controller as it can be upgraded to use a bluetooth module at least, but beware that the temp sensor not locking/working seems to be a common complaint on the other reviews.Purchased the unit for use in my Fifth Wheel. First impression are that it is well built and feels solid. Cooling fins on the back would not be my first choice, but I used 1/4" spacers to insure good airflow.I was not impressed with the mounting design though. It is four slotted holes that sit with-in the foot print of the unit on the backside with the cooling fins. So another words you have no real access to the screw heads to tighten them down for secure installation. This was a concern of mine since it is going in a trailer and I'm afraid one good pot hole will send it flying off the wall. It does ship with a good template for marking your holes to drill so if you were to set some studs maybe you could use a nut to secure it. But again the slots are really out of sight and anyone who has mounted equipment like this know how difficult it can be for two holes to line up, let alone four.Wire terminals are nice and large and easily accommodated 8AWG cable.The display is easy to read but it could stand to be back lite. The instruction for operating the menu didn't seem to be the best, but maybe I was having an off day. I ended up finding a YouTube video that helped.A bonus (I thought) is that the unit has a set of terminals for "load out" which can be set to more or less run aux equipment that are not apart of your normal electrical system, and it has some preset programming for it. So items like fans for the batteries, or maybe a string of lights to kick on at night.I used this as a temporary charge controller on my camper and worked great. Have 200 watts of solar hooked up to it and a recent camping trip and kept my batteries in working condition even with the cloudy days.Well made worth the money, works on my camper with two one hundred Solar panels.I have been using my unit for 4 days now. I have an error message (E15) and their manual only lists to E13!!I have tries to call multiple times, I emailed, I tried their live chat, no one is answering and I am left with no power!! This is not the headache, or the product, you want. Trust me!