For the most part they work as they should . One would not power up at all and one smoked as soon as the relay was activated . So six out of eight work . No directions sent with any of them . On line directions are sufferable . I was able to accomplish the task that they were needed for . Minus two stars for bad QC and no paperwork .

This is a good digital low voltage disconnect module. The voltage readings are reasonably close (around +/- 100mV) and the unit works reliably to shut off the load once the battery voltage drops below the set amount. I like that the hysteresis to turn the load back on is user configurable, so under a high rate discharge a larger hysteresis can be used to prevent infinite on/off cycling from voltage drop and subsequent recovery.The module uses about half a watt and the relay uses another 0.3-0.4W when the coil is energized, for a draw of just under 1 watt. This may be a bit much for smaller battery banks.

I had a hard time understanding the values, but I came up with an example to follow. Keep in mind if the battery isn't charging the input voltage will eventually drop to your set cutoff voltage.To command it to provide power out, set the if linput voltage is higher than, provide power out: yes. Number.Left button double press, set to .5 which commands controller to provide power out if input is above 11vdc and if cutoff is st to 10.5vdcTo set the cutoff, the low voltage protection...voltageRight button double press then change display to 10.7 based on SOC safe low voltage for lifepo, and maybe 11 if agm.In the above example, it will cut power out st 10.5v, and when charging, allow power output when above 11v Input.

These do work, but they have a fatal flaw that will limit where they can be used. The whole idea behind a low voltage disconnect (LVDC) is to preserve battery life - to ensure you don't drain your battery too much. However, with a product like this that has a high parasitic current draw, it will itself drain your battery, even after disconnecting the external load.The current draw when in a disconnect/no load scenario is around 35mA. This may not sound like a lot of current, but if dealing with a single battery, say a 100 Ah deep cycle battery, this can continue to drain it a fair bit over a period of a day (0.035A x 24 hrs. = 0.84 Ah per day). This is more significant than it seems in that said 100 Ah battery, at the time of disconnecting, is at a much reduced state of capacity, depending on how conservatively the LVDC level is set. Say you disconnect at 10% capacity - that means that over a period of 12 days that parasitic load with it disconnected has completely drained what was left in that battery and it is now getting damaged due to over discharge. When the LVDC is active (voltage is above the disconnect level and the relay is on) the parasitic power draw almost triples to just over 90mA. This is just too much parasitic power draw to be useful in low power circuits, and this is not designed to handle high power loads so it can't be used in high power circuits, unless it is used to drive a larger relay.This does leave the awkward question - where can it be used?Aside from the parasitic current, the accuracy of the volt meter is not great. At first it was 0.3V off, which for anyone who works with batteries knows that a 0.3V difference can be significant. It does allow for calibration, which is good, but even when calibrated it still drifts in accuracy when the voltage deviates from the calibration voltage. I found that even going about 1V past the calibration level it started to indicate 0.1V off. If you calibrate it right at the voltage that you want it to disconnect at, then measure what it reads when at the reconnect voltage and adjust the offset accordingly, you can get it to work accurately, but still, this is extra fuss rather than just being able to set it to desired levels out of the box.I suppose if you have a high capacity power system, and only want to use this to drive a larger relay, it could be useful, or have a system where once it disconnects the battery voltage will recover in a short period of time (like a vehicle that will be restarted in a few hours or something) this could be useful, but I think if they fixed some of the issues with it (like using an LCD display instead, have it draw a few microamps rather than milliamps when disconnected) and gave it a more accurate voltage measurement circuit, this could have a lot of utility. I do find that it is quite limited the way it is and as such I can't wholeheartedly recommend it.

This review is for the "12V-36V DC Voltage Protection Module Digital Low Voltage Protector Disconnect Switch Cut Off"So this is pretty easy to setup, bring the DC voltage in to the + and - terminals for the input. Send DC voltage out via the + and - terminals. Easy on this part.There's no actual instructions in the box, at least mine did not have any, but the Amazon listing has all of the details and instructions. Two buttons allows you to raise or lower the point that cut-off actually takes place. This device protects your 12v-36v battery from over discharge. In my case my Ford Transit Connect will let anything plugged into the cigarette adapter to drain the battery down to 0v. So cut-off circuits like this one are critical.Please remember that this device can only handle 8 amps of power when the battery is above 12 volts.The reason I am giving four stars instead of five is that it's not entirely the most accurate. The reading of the power coming in was off by .4v and the cut-off was happening, I believe, a little before my settings. Not a big deal as you can calibrate the unit for the voltage coming in and for cut-off just set it a little off to the point that works for you.All in all, I would absolutely recommend this to anyone needing a low voltage cut-off for a great price.

Ordered two of these and both showed up inoperable. Returned the two original boards and got two replacements, only one (out of 4 total) actually seems to work. I have low confidence that it will continue to work.

These modules allow you to connect a something to your battery. The module monitors the battery voltage and if that voltage goes below the value you set, the module will disconnect. Perfect for RVs, boats, trucks, off-grid, solar sheds, motorcycles....Build quality is pretty good. The modules do not come with a housing.Setting the cutoff voltage is done with the plus and minus buttons. Pretty intuitive.

The main issue is the current consumption. About 20mA while off, and 80mA while operating.There is some reaction delay for the relay to turn back on, in the 30s-40s range. The off operation is instantaneous.Setting the parameter is easy but not intuitive. Printing a copy of the description would be a good precaution, as there are no instruction in the box.

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There seems to be a lot of confusion about this module specifications and its features. So, let's get that clear.First of all, this module seems to work reliably with voltages starting as low as 5.25V, not 12V, as the description specifies. The power consumption is within specification (For example, at 20V, the power consumption is about 0.5W (about 25mA).Now, let's talk about features and settings.It seems that the full manual for this module is hard to come by, and to avoid risking that my review is rejected because it contains an external link, I'm going to provide a concise, yet comprehensive, summary here, in my review.The features and settings are as follows:View deactivation voltage: Single-press “+”Set deactivation voltage: Double-press “+”, adjust using +/- keys within range 00.0V – 36.0VView reactivation voltage offset: Single-press “-”Set reactivation voltage offset: Double-press “-”, adjust using +/- keys within range: 00.0V – 36.0VCalibration: Long-press “+” and release*, set displayed voltage to match the supplied oneSet activation time delay: Long-press “-” and release*, adjust within range: 000 - 100 minutes* These modes are not activated until after the button is released. Pressing the button for 2-3 seconds is sufficient.Note that "+" button is on the left, and "-" button is on the right.This is counterintuitive, so keep that in mind. Fortunately, they are properly labeled on the silkscreen.To exit from any mode, simply stop applying any input and the module will return into main mode automatically after some timeout. The settings are preserved even when power is disconnected, which is great.Hope this helps, and if it did, I'd appreciate an upvote, as it would encourage me to keep providing useful and detailed reviews, like this one, in the future. Thank you!Update May 7th, 2025:Since my review was published, the seller has added the instructions for how to adjust the settings and program this module into the listing pictures, but I'm going to leave the instructions I provided above in case someone wants to copy them as text, because you won't receive a paper manual with these modules.