I first want to preface this by saying I am not encouraging anybody to use or not to use a Chargery even though I stock them and sell them to forum members at a discount. I only did this because they work perfect for my situation and I as well as some others liked the product. I noticed problems with ordering fro ICGOGO and thought it would be helpful to have some in hand here in the US. That being said this product can work in almost any situation even though it may not be the correct tool for every situation.
The easiest and best way to use a Chargery is without relays at all. I use a Midnite Classic SCC and a Samlex Evo inverter/charger. Both of these devices allow for external control via a 12V signal, which the Chargery so nicely produces. The Midnite has a Aux2 input that when it receives a 12v Signal allows for charging and when it has no signal Charging stops. The Samlex has similar. The one drawback with the Samlex signal is it turns the whole thing off so if you have a LVD you will not be able to use the Samlex for charging; however if you have it hooked up to grid power for charging and enable grid charging you should never reach a LVD situation.
The next best way would be to use Solid State relays to turn your inverter off by placing the relay either in parallel or series with the units power switch. This could be a cheap hack at around $20.00 and would have almost no parasitic drain from the relay on your system. Some SCC could be controlled in the same fashion especially the all in one units but again they would have the problem of not being able to charge or discharge at that point. This may not be the end of the world if your battery is truly bad and may even be preferable to using an unbalanced pack.
Hopefully if your pack is balanced correctly the Chargery never shuts anything down and the inverter and SCC properly take care of HVD and LVD. The BMS's main purpose would be to maintain balance through passive balancing and turn things off in a last chance emergency situation.
Another option is to use a relay on the AC side of your inverter higher amp DC-AC SSR's are pretty easy to come by and the AC current is usually much lower than the DC current so the relay is pretty simple. I really think this could be a great option if you can not easily control your inverter.
The last way is to use high amp relays to interrupt the discharge between the battery and the inverter. This is my least favorite method because almost no matter how you do it you create a lot of heat and unnecessary battery drain. For the SCC you can place a relay between the PV array and the SCC so that the SCC stays connected to the battery and you will not have any issues of panels being connected to a SCC not connected to the battery.
Latching relays could be another option however I have yet to see a simple reasonably priced solution.
All ofthe ways mentioned above would work with low temp and over current protections as well
The easiest and best way to use a Chargery is without relays at all. I use a Midnite Classic SCC and a Samlex Evo inverter/charger. Both of these devices allow for external control via a 12V signal, which the Chargery so nicely produces. The Midnite has a Aux2 input that when it receives a 12v Signal allows for charging and when it has no signal Charging stops. The Samlex has similar. The one drawback with the Samlex signal is it turns the whole thing off so if you have a LVD you will not be able to use the Samlex for charging; however if you have it hooked up to grid power for charging and enable grid charging you should never reach a LVD situation.
The next best way would be to use Solid State relays to turn your inverter off by placing the relay either in parallel or series with the units power switch. This could be a cheap hack at around $20.00 and would have almost no parasitic drain from the relay on your system. Some SCC could be controlled in the same fashion especially the all in one units but again they would have the problem of not being able to charge or discharge at that point. This may not be the end of the world if your battery is truly bad and may even be preferable to using an unbalanced pack.
Hopefully if your pack is balanced correctly the Chargery never shuts anything down and the inverter and SCC properly take care of HVD and LVD. The BMS's main purpose would be to maintain balance through passive balancing and turn things off in a last chance emergency situation.
Another option is to use a relay on the AC side of your inverter higher amp DC-AC SSR's are pretty easy to come by and the AC current is usually much lower than the DC current so the relay is pretty simple. I really think this could be a great option if you can not easily control your inverter.
The last way is to use high amp relays to interrupt the discharge between the battery and the inverter. This is my least favorite method because almost no matter how you do it you create a lot of heat and unnecessary battery drain. For the SCC you can place a relay between the PV array and the SCC so that the SCC stays connected to the battery and you will not have any issues of panels being connected to a SCC not connected to the battery.
Latching relays could be another option however I have yet to see a simple reasonably priced solution.
All ofthe ways mentioned above would work with low temp and over current protections as well
