Time to dump all this rubbish about damaging the MPPT charge controller if, you disconnect the battery before the solar panels, well, in the case of a Victron controller at least.
I couldn't go along with all this DESTRUCTION tosh being banded about so signed up with Victron's Q&A board, and to cut a long story short; I finally got this reply:
"I have got a few more comments back from the Victron MPPT hardware engineering dept:
- The MPPT should NEVER break due to a battery disconnection. Even if that happens often.
- If no other load is applied to the DC bus when the battery disconnects, a short voltage overshoot may occur.
- The overshoot should only last a second or two, if it occurs, then the voltage will stabilise at the voltage set point of the current charge state (eg float, absorption), including temperature compensation.
- Be careful if also using a remote battery sense option, if the MPPT sees a variation between the battery sense and the voltage at the terminals, it will adjust output to compensate (up to + - 2V)
- The MPPT is not designed to be a power supply, it is a battery charge controller. So fast load variations may lead to voltage dips and spikes when the battery is disconnected and loads turn on and off. The MPPT output voltage will stabilise when loads are stable though.
- Using the MPPT with a BMS like this that disconnects the battery is allowed by Victron, from our equipments perspective. In fact our own
- SuperPack lithium batteries operate on this same principle, where the battery disconnects itself internally to protect itself".
- So, it would appear that it is perfectly fine to use a common port BMS with a Victron charge controller, that will, in effect, be disconnecting the batteries whilst the panels are still connected.
People should try a lot harder to get their info from the horses mouth, there's far too much tripe being banded about as fact when it is just a belief or, to put it another way; crap.
- A link to my Q&A with the Victron community manager:
community.victronenergy.com
Hope this information from Victron engineers (the horses mouth) gets rid of all this panel/controller/battery connection fretting.