DC Power Switch Module, 12V 24V 36V 48V 10A Battery Power Source Controller Automatic Switch Emergency Battery Change

I’m using this for a little different application. Instead of switching to a battery back up, I’m switching off of batteries to an AC/DC converter. My son-in-law is using solar power to run a 24vdc pump for his hydroponics system, but if he has no sun for a few days, the batteries don’t get charged enough. I set this up to switch power to an AC/DC converter when the battery level gets too low to keep the pump running. It’ll switch back when the batteries get a sufficient charge. Essentially, I am using the Shelly relay and MQTT to do the switching. Do note, as others have mentioned, there is a delay of about a half a second in switching between the two sources. This is not a problem with the pump. It may be for more sensitive electronics.

Diesel Heaters do not like this switch as the delay in switching over to battery backup is to long, Causing unit to shut off and smoke out. This switch would work on something that isnt so fragile to voltage disruption.

It did not switch over fast enough from AC power to DC battery for a 2k Chinese diesel heater to keep running.

I use this as a switchover between the battery and 'line' power when I have my device charging. As soon as I plug in the battery charger/power supply this unit removes the load from the batteries and places it off on grid power allowing the batteries to charge correctly without a load on them. It is not quite a 'UPS' type solution as there is about a half a second loss of load power when it switches over. But it does the deed well for my needs and I bought a second one for another project. My setup is 12 volts DC, 6 amp load.

I am using this module to switch between two 24v power sources, 24V lithium battery and DC power supply. The current draw is less than 5A for my application. I believe that the device is rate for up to 10A, so I am not pushing the extremes; nonetheless the relay has functioned as expected and I have not thus far detected any significant heat.

Only sort of works. It seems to switch just fine but the switching speed is abysmal. Unless whatever you are powering has it's own internal battery it will likely restart when switching power. If your application is fine for brief power outages as it switches should work fine though

Can't beat the price. Works as it should. Wish it would switch over a little faster for uninterrupted power but again, for the price you can't go wrong.

I've only had it installed for a few days but it does what it says it will do. My application is for switching between ignition hot battery in a car to solar to charge a solar generator. When the car is running 12v is hot and the switch connects car power to the solar generator. When the car is off its defaults to the solar on the roof as the input. I put mine in a waterproof junction box which is JUST too small, but I made it work. EDIT - One of the screw terminals was broken, though I was able to solder it in. I accidentally shorted it though. it is not protected against reverse polarity, FYI.

Cheaply made but works

Great product that did exactly what we wanted. I ran 12v from our vehicle that is the primary power to our RV but it pulls from the battery when disconnected. Only 4 stars as it is just a circuit board and you have to have a housing that protects it which is a bit bizarre.

No longer works after three months.

This thing works as described, however, it doesn’t switch fast enough for my application. I’m using this for a diesel heater, even though it switches from my 12v converter to my 12v backup battery, it doesn’t switch fast enough for my control board not to shut down and turn the heater off, which is disappointing.