Victron Energy BatteryProtect 12/24-Volt 65 amp

This product works exactly as advertised. You need to understand this device is to be put in a circuit with loads only. It is not to be used where a charge controller can charge the battery (reverse current). Some devices can produce something called back EMF and they should be avoided as well. Inverters come to mind. I use mine to energize a relay to turn off or on a boost converter. The boost converter 24v charges a solar generator or battery box. The voltage on/off was exactly as described in the manualThey could do a better job in the manual describing what devices are allowed downstream.

I purchased this unit a few years ago, and it's functioning great, as intended. very reliable.

Just like all of my victron products, it was easy to set up, and I feel like it will protect my batteries.

Very good

I wish I saw more clearly that amp flow is one direction only. You cannot charge backwards through the battery protect. I was hoping to use the aux switch to disconnect the battery from charge when below freezing but you have to buy an additional battery protect, one for charge and one for loads.

Works good.

The product works quite well within the relatively strict guidelines in the manual (which is a problem, see later). I was able to configure it easily and tie it into the Victron MPPT charge controller (TX pin on the MPPT to the Remote pin on the battery protect). I have several critiques:* First, the unit imposes switching delays rather gratuitously in some cases. It should not impose any switching delays based on the REMOTE input as long as the previous switch didn't happen too recently. Delays are obviously important to avoid false triggers, but the algorithm could use some tuning. This is a particular problem when a Victron charge controller is used to control the battery protect, because the charge controller imposes an additional delay itself.* Second, and this lost them a star, there is significant current leakage from input to output when the unit is "off". The output will float up and this causes the power station I connect one of them to to repeatedly engage its input relay. I had to add a 10K resistor from the output to ground to get it to stop. A product like this should already have such a resistor internally or provide a little socket to which a resistor can be added, or otherwise be designed not to have any leakage current in the first place.* The product warns of switching under load. Switching a FET under load is a simple function of temperature and gate voltage, the product simply shouldn't allow itself to be turned "on" if its too hot. It absolutely should allow switching under load and it is fine if it stipulates a stronger voltage on the control input if that is what it takes to switch the gate of the FET fast enough. It doesn't though.* Finally, and this lost the product another star, it warns of damage if reverse current is applied. This is basically a cop-out for sub-standard design. Reverse current damage can occur because the product is not using a back-to-back FET configuration, so reverse current will flow through a protection diode built into the FET (which isn't designed to handle a lot of current) and melt it.These warnings are basically a "cover-my-ass" problem, covering for poor design. What is the point of having a product that is able to handle "60A" when you can't safely put any real current through it due to all of these use-case restrictions? That's why it only gets 3 stars.For my own use, well, I *AM* switching an inverter directly through this product, and my solution to the reverse current problem (which occurs if the inverter's capacitors feed power back through the protect device in the reverse direction)... my solution is to put a big-ass schotkey diode across the input and output terminals to sink any reverse current. That particular diode can easily handle about 5A of reverse current indefinitely without a heat sink, and a lot more for a sub-second interval, so it should have no problem with reverse current cases as long as the input to the device is connected to a low-impedance source like a battery.It is also possible that ripple feedback from the inverter due to the power factor of the AC devices hanging off of it can cause a reverse current. So if you do use a big-ass diode to work around the problem make sure that it doesn't overheat.So in short, I had to add (A) a resistor to ground off the output, and (B) a diode, and now I can use the device as an actual switch... though in my case, I'm not putting more than 20A through it. And (C) made sure that nominal operation under load does not overheat the diode. These things really should have been built-into the device in the first place. Picture included.

Ok.