2pcs 12V-36V DC Voltage Protection Module Over Discharge Protection

Been 3 years. In use everyday saving my battery every day. I use it on a dashcamera set up. Instruction bad. But video on YouTube showed how to pogram it and its easy once you watch it. 10/10 product and reliable.

The built in voltmeter is within a few hundredths of a volt to my Fluke meter. The disconnect was within 0.1v of the disconnect setting. Perfectly acceptable for a $5 part. Some have complained that the disconnect continues to drain the battery after disconnecting the load. In my application, I have a 12V SLA battery, an AC to DC power supply set at 13.5V (float voltage) and a load. I connected the power supply and load to the VIN terminals, and the battery to the VOUT terminals. This is opposite to the published diagram. When the AC voltage drops out, the load stays on until the battery voltage drops below disconnect (12v), then the relay opens and the battery is disconnected and has no parasitic load. When AC power is restored the relay closes and the battery gets charged.

Another seller of this same item has excellent directions on the amazon page. This seller doesn't. I took off one star for directions. It looks to me like several sellers are selling the same item. The first one I got, from another seller, did not work at all. I opened the first one from this seller and it worked like a champ. And I have a spare. Every feature worked fine. When I lowered the voltage below the cutoff, it cut off great. When I raised it 2V over the cutoff, it came back on. I did not have to adjust the voltage, it was spot on to my meter out of the package. Perfect. I have a 24V LIFEPO4 battery, and it is nominally at about 26V. By 24V, there is almost nothing left in the battery, but my circuit doesn't like low voltage, so the cutoff at 24V makes a clean off, so if I forget to turn it off (yes, I did that once, with bad results), the circuit is protected. This is even higher cutoff than the battery pack bms (2.5V/cell=20V) .

This is a very simple but ideal unit for Battery systems. I have configured one with a Battery Charger Plugged into a IOT Relay to turn the charger on when the battery is 25% low and then turn the charger off when battery is fully charged. The other Voltage Protection Module I will use to disconnect the battery complex if the voltage gets too low. The one little funny issue I had set (left button 11.5V) then you set a different voltage (right button to .5) this is wired until you understand if the full voltage is 12V and the charge voltage is 11v the different voltage is .5V. Yea I know a little wired, once you figure this out its easy to work with. On one of my units the voltage read .1V off no problem if you want true 12v you set it to 11.6v. These are very inexpensive units that do just what I needed them to do even more expensive Voltage Protection Module can't do what these little guys can do.

1st one lasted about 4 months on a solar configuration, now its not accurately reading voltage ( low by about 1-2 volts) but did the job. On the second one now, for cheap price still worth using to tinker with, I would spend more if you need something reliable long term.

I connected my 12v li-po drill battery to this low voltage cutoff and it showed 12.3v. I then connected the same battery directly to my dedicated Klein voltmeter, and it confirmed 12.3v (12.26). I'm using a 12v Milwaukee battery with 3 cells, and it's worked for me with no issues for 2 years Since I have a 3 cell li-po pack, I don't want to go below 3.2v per cell which would be a total of 9.6 on this low voltage cutoff. To give a little more buffer, I set it to cutoff at 9.8, so that it cuts off when the first cell hits 3.2v. I may set it to 9.9, although the default on mine was 10v. It's splitting hairs at this point, but I like the ability to customize the cutoff depending on the battery chemistry. I'm really glad to see the voltmeter that's built in is accurate- that's an important part of setting the cut-off. I will validate the volt meter on each one of these I use, just to make sure they are set correctly

One board was showing voltage jumps from 16 volts up to 25 volts and after just a minute or two shot the magic smoke. The battery I was powering it with shows steady 18.6 volts and the second board was showing the same voltage and worked. I am having a hard time trusting the second board.

Does the job