EDIT 2: Please, I really appreciate your help but some of you are answering without even reading the post nor the other answers. I just need an advice on what latching arduino operated switch I should buy, nothing more. Thanks.
Hello, I'm trying to choose a latching relay, preferably from the most famous chinese online store, but I actually just need a way to find it even if somewhere else.
The project
My electric motorcycle (Ovaobike MCR-S, 144V 9.6 KW battery) doesn't have a system that stops the battery charge, so I want to build one by opening or closing one of the wire inside the cable that goes from the outlet (220V AC) to the charger / transformer (1.2 KW) before it enter the charger, depending on the battery current level of charge.
Let's say that at 80% battery I want to open the circuit so that no more current goes through and the charge stops. At this point, even the current to my arduino and the relay stops coming. The next time I power On the motorcycle, the Arduino resets the relay so that I can plug the cable again to charge, so I'm searching something that:
Acts as a switch to close or open the circuit (220V AC to 1.2 KW charger).
Is controllable by an Arduino.
Stays in the last state it was, even in case of power outage.
I've seen many relays and latching relays that turn back in the initial state in case of power outage, I think that every Songle module do that but I don't know for sure.
Can someone point me to a component or give me some links?
The battery chargers for a 9.6 KW battery of an electric motorcycle costs way over 20 bucks, and then I must put my hands on that and on the motorcycle cables and batteries. I prefer to use a Relay or similar component.
Depends on the relay working logic.
If I have two separate triggers, one to open and one to close, I just close the circuit once the power is restored.
If I have only one trigger that goes flip flop, I have to store a variable in the Arduino so that it will check it once the power comes on again
The Arduino checks the battery charge and decides when to shut off the relay. It also does some other things. Also without power neither the arduino nor the relay will work so it must be latching
I don't know, but I leave it too much time charging it reports an error. Also I can't decide at which battery level I want it to shut off. I just need guidance on which relay or other form of Arduino operated switch to use
I assume that the charger draws gradually less current when the battery is almost fully charged. You could measure mains current to the charger, and switch off mains power when that drops below a certain value.
Leo..
Ok, I see. But is it normal? Maybe it's not working fine. All the bicycle chargers I have seen report the charge level and stop charging without issues. Cars also.
It sounds even dangerous, instead of an error who knows what could happen someday.
... and if your battery is in fact LiPo (as practically all are) and your charger does not stop charging then you are up to a firy surprise sooner or later 'cause either your charger is malfunctioning or the battery pack is.
