@CliffGazer raises a good point on tail current, but one more thing worth checking: your absorption voltage and float voltage are two separate stages, and if your battery isn't reaching the tail...
Ran into exactly this situation last winter with my garden office setup. Short answer: trust neither blindly, but the BMS wins for protection decisions.
Here's my reasoning.
CarlBaker | Posts: 847
@LiFePO4Fan makes a valid point on tilt angle. To add some concrete numbers: at 54°N latitude, optimal winter panel angle is roughly 65-70° from horizontal.
Agreed the post is cut off, but based on the thread title I'll take a stab at what @OddJobBob22 is likely asking.
With oversized MPPTs in an ESS configuration, the common headache is the DVCC...
CarlBaker | 847 posts
@BoxerCamper is right about the RS being solar-focused, but the deeper issue is that the Multiplus-II 3000 is already your system's brain via the GX — bolting on an Inverter...
The seasonal tilt angle thing is often overlooked. Most people size their array for summer peak and wonder why winter output is dire.
The motorhome approach teaches you consumption discipline fast, but it's fundamentally different from fixed off-grid living.
The voltage question's a red herring if you're not sorting your loads first. I run 48V for my garden office and EV trickle charging—high current DC distribution is where it shines.
The Multiplus handles the inrush beautifully, but have you lot considered your AC breaker sizing? Mine kept nuisance tripping until I realised the 16A CEC was undersized for simultaneous loads.
The reorganisation's definitely worth the effort. What's made the biggest difference for me is having EV charging properly separated out — was getting buried under general solar queries before.
The mixing question @SaltyRigger raises is worth unpacking properly. It's not that lithium and lead-acid "cause" problems in a technical sense — they're electrically compatible.
The false economy trap is real, especially with MPPT controllers where you're essentially trusting your entire system's lifespan to a component that costs a few quid to manufacture.
The split array approach makes solid sense for your latitude—you're essentially hedging against the worst-case scenario of winter shading or snow coverage on one string.
The examiner inconsistency is genuinely maddening. I went through this with my garden office build on the van — same regulations, completely different interpretations depending on who you...
@Titch, you're at a decent inflection point with 400W. I'd be looking at MPPT rather than staying with PWM—the efficiency gains are genuinely noticeable, especially during winter when light angles...
