I always put the isolation switch ("kill switch") on the battery negative. Battery negative -> switch -> shunt -> negative buss bar -> chassis and all other negative returns. I have some positive disconnect switches for individual circuits I may want off.
Kill switch doesn't turn off all power
- Thread starter Bribenn
- Start date
gotcha. I took the extra (-) cable out.That's where I was headed.
It helps to think of the battery as a "load" on the charge controller.
By isolating the battery, you're only removing part of the load, so the charge controller still sees the loads as part of it "charging" duties. The removal of the battery from the "loads" likely creates an imbalance where the charge controller shuts off after a short period of running either due to a change in load or solar insufficient to maintain voltage.
Your Victron battery monitor is completely useless with the extra (-) cable bypassing it. Likely less than half the current going in or out of the battery is passing through the shunt.
Do you know the proper way to incorporate a switch that will turn off all power?
Your charge controller is like a second battery when the sun is shining. The reason it eventually turns off is because the controller likely needs battery power to start so as soon as a cloud passes or a load over powers the panel, the charge controller dies and with no battery, can’t restart itself.
Because you have two power sources you really need two switches. If you don’t want to buy another switch, move your existing switch to just before your loads. This will kill all your loads but it means you can’t disconnect your charge controller from the battery.
This shouldn’t be much of a problem because the charge controller should already be turning itself off when the battery off full.
Be careful of your charge controller’s quiescent power draw. Mine is very low at about 15 miliamps so it drains about 1% of my battery every 12 days.
If available, it would be published in your charge controllers specifications. The mA draw of a MPPT SCC is generally not a concern with a typical system.
You don't want this. If you use switches, each should ONLY do ONE of the following:
1) disconnect battery from inverter/12V loads (your main switch can do this)
2) disconnect panels from controller (you don't have this)
3) disconnect battery from controller (you have this in your 70A breaker, but the wire should be run directly to the battery)
#2 is particularly important. Some charge controllers indicate that the battery must be connected first before connecting the panels. In some cases, failure to do so can damage the controller.
Thanks!
I'm going to disconnect everything from the charge controller and then rewire directly to the battery and then plug in the solar panels again.
Does the charge controller not need to be directly connected to the battery?
