MPPT Solar Controller, Solar Power Controller, MPT-7210A Solar Panel Regulator Controller(100W - 600W)Aluminum Alloy LCD Display Solar Controller for Home Industry Boat Car

Agree with Jim - fan runs full speed no matter what setting. Had found others reporting issues with the fan running at slower speed in video reviews so it appears that was disabled at factory.Be sure to understand the battery voltage MUST be higher than input panel voltage otherwise the panel is passed thru, there is no bucking regulation, and that could possible overcharge your lithium packs and lead to a dangerous fire! I was watching a pair of 12v 100w panels in series overcharging a 28.7v pack (7 4.1v parallel cells) and wondering why the output voltage was too high and still pumping energy into an already charged pack in 'constant voltage' stage. Have also read it tends to output a volt or half more than the setting. After adding in the 2nd 28.7v pack - for a total of 57.4v - and setting the battery voltage on the unit to 57v did it say charge complete. This is affordable, basically works, takes some effort but can be dangerous if you do not understand that part. I had a bunch of cells charged to 4.22v - so much that another charge controller, trying to discharge thru some big resistors, said "balance port over" - and had to just discharge thru a 4 Ohm power resistor without control for a bit to get it back under control!I could also reconfigure the panels for parallel to get this to work with 28.7v batteries.Love the display :) Operation is easy once you practice some.

Works as advertised. Directions a little hard to follow, could be better

This charger is not MPPT as other people pointed out. You'll need to enter the solar panel Vmp for it to pull down to so when the panel is partially shaded, it will not track lower to utilize the solar panel built-in bypass diodes to bypass shaded cells.The fan speed control did not worked for me at all, it's always at full speed. Also the heat sink inside is not in contact with the aluminum box at all, which defeat the purpose of the aluminum box; they might as well used a plastic box to save material and cost.This is a boost charger so the output voltage has to be higher then the input voltage. However, the charger has a mosfet to disconnect the output (i.e. when you turn it off) so they could have auto turn off the output when the output voltage exceeds the setting and thus allowing the charger to be used to charge battery with lower voltage than the solar panel.

I am charging e bike batteries on my sailboat using two 10 watt solar panels and it's chugging along with a quarter amp trickle charge. Very sweet, the setting is 54.6 volt and the amp defaulted at 5. It restarted every 3 seconds until I decided to reset the charging current to the amperage that it reset. That was .26 amp. Now it is constant current and chugging along with ease. I order a fifty watt panel to add to the boat power grid and will use the boats 12 volt output to charge them.

I hooked it up and got no power! I would not buy this product again.

The unit _can_ start charge mode automatically when powered on but you have to set that setting. it involves going into what i'll call the "extended settings"With the unit "off" (not in charge mode). the [set] key will cycle through. load preset, panel voltage, output voltage, output max amps, and save preset.When you are on the output amps setting, if you _long_press_ [set] key it will continue on to the extended settings. Screen timeout, Battery AH, Charge Timer, lock keys, power on mode (wether to start charging when device is powered, or wait for the OK button to start charge mode )Apparently the fan speed setting no longer has an effect. several reviews here concur with my observations. the internet is full of videos where with a lower fan speed battery voltage detection was incorrect. so there's an assumption the factory disabled lowering the fan speed as a workaround.Fan is loud.If you don't set the panel voltage value higher than your panels voltage, then the unit will appear to cycle on and off and basically not be very functional.

On a mostly sunny day, this unit produces a useful output only half the time. The slightest decrease in solar flux (a small cloud or haze) causes it to reset its output power to zero then wait ten seconds to resume, and upon resumption slowly, ever slowly, ramp up the output to nominal. Looking at the image, you will see that the unit isn't capable of maintaining the PV's Vmp of about 56V.Worse yet, a short rain squall can shut off the unit entirely. Then, not only have you lost the entire record of the first session, you have to also run out and restart it or you will miss the entire rest of the solar influx for that day.There have been some complaints of batteries ruined by this product, but that is due to user error. Make sure the highest voltage your solar panel can output, that is the Voc, is less than your battery. If it is higher, this charger will pass that voltage through and over-charge your battery.Although this unit has an aluminum case, all of the heat sinks internally are small and not connected to the case thermally or mechanically. So it might as well have had a plastic case.I could find no electrical continuity between either the positive or negative input and output rails, so they may be galvanically isolated.The unit cannot be set to automatically turn on at the beginning of the day. You have to start it up every day manually by pushing the OK button.The fan speed IS SETTABLE from the control panel, but paradoxically, the fan speed does not respond to temperature changes, and is always on in ON mode even if there is no current flowing into the battery.The display backlight brightness is also settable from the front panel.

Total junk. After 3 seconds of running, AMPS drop to zero, and its not putting out any power