Switching from AC-coupled to DC-coupled solar. Currently have a Multiplus II 48/5000 wired directly to a Fogstar 5kWh battery. I’ve ordered an MPPT 250/85, a busbar seems overkill for just 3 components (could be wrong, do I need a Lynx?), but unsure whether I should stack the lugs on the Multiplus side, or use the second set of battery terminals? I’d like to learn the reasoning behind it too:)
Always better to not lug stack. I cringe when i see it and have troubleshot way to many system where is it the main problem.
The reason is contact seating and surface contact area, as well as current.
Lug stacking produces extra heat. Then you get thermal cyling on lugs. (So its more a mechanical problem that become and electrical one)
It is better for ESS for the mppt to be closer to the inverter, but if you don’t want a bus bar then use the space on the battery.
On the other hand a bus bar installed makes future work such as repair or expansion much easier and for basic fusing and component isolation is also great.
Understood, thank you for the advice!
I think the advantage of using a busbar like the Lynx is that you can more easily add individual fusing for each of your three devices.
It’d be good if a short in your MPPT wiring blew a fuse rather than appearing as a short across your Fogstar battery!