the prodigal son
New Member
- Joined
- Apr 10, 2020
- Messages
- 27
i ordered this BMS and it didn’t come with the relay. Does anyone have experience with BMS?
I have it wired to certain circuits of my home. Nothing but tv’s electronics ect. I’ll put a photo on here of equiptment.Ok what equipment are you using. Can you tell us your panel,SCC, and inverter specs. I would be glad to help.
I have found the chargery relays directly from China. This is what they have told me:
12V 100A relay is suggested,
the price is 28USD, two pcs is 56usd, one relay is for charge, another is for discharge. the freight is 20USD. total is 76usd
Are these relays good relays, is this a viable option? I’ve just really not done anything with this solar system in 9 years and I am very green.
Thanks
Stacy Hayes
Glad for the info I wanted to use those Chargery relays too but was a bit doubtful about them.The general consensus is that the Chargery relays are crap-tastic and even potentially dangerous if they see anywhere their rated load.
Some of us picked up used TE 500a relays from eBay to use instead.
Glad for the info I wanted to use those Chargery relays too but was a bit doubtful about them.
Is this the relay that you referenced-Tyco TE Connectivity Kilovac Relay EV200AAANA RELAY CONTACTOR SPST 500A 12-24V
Thanks Pacer. ??Yes, that’s correct!
The Chargery uses two relays. One to control the solar charge controller circuit and one to control the load circuit which is typically your inverter.Ok thanks. I need a relay and the BMS is a 100amp. What size relay do I need. They are asking me the maximum charge and discharge rate. Help. Lol
What is your SCCThe Chargery uses two relays. One to control the solar charge controller circuit and one to control the load circuit which is typically your inverter.
The load relay is pretty much straight forward. Either use the peak current or battery fuse rating of the inverter. Go about 25%-30% over the maximum continuous battery of the inverter.
The relay for the charge controller is a little less straightforward. You should NEVER disconnect your battery from the charge controller while it is connected to the PV array. Doing so may fry your charge controller.
That means you should use the relay to disconnect the PV array from the charge controller, which will stop current flowing to the battery. A load diversion might be an option if switching the battery circuit.
The PV array is at a higher voltage than the battery. If the relay can handle the higher PV voltage is the question. Read the specs.
Personally, I'm looking at MODBUS to talk to my charge controller to turn off the charge controller and avoid relays all together.
I've already figured out that I can use the low current relay wire from the Chargery BMS to trigger my inverter's remoter switch terminal with 24V at 8 milliamps.
Once I figure out MODBUS programming of my charge controller and relay driver it will probably take less than 50 milliamps to power the turning on and off of the charge controller.