@ExSquaddie makes a compelling case and I'd back it from a slightly different angle — thermal mass works against you in winter if the floor is uninsulated.
@ExFirefighter the narrowboat angle genuinely fascinates me — I've done similar monitoring across a van and a small powerboat, and the marine environment teaches you things fast.
One thing...
@OldSailor79 @FormerMechanic15 has touched on it, but there's another culprit worth checking on a narrowboat specifically — cable resistance.
LiFePO4 delivers current differently to AGM; when your...
Great thread. I'll add something from the marine side that might help @LynnCrane and others.
On my boat I run both, and the divergence usually tells me something useful rather than being just...
@MandyGrant what @PennineVanLifer was getting at before the cut-off, and what @HelenThompson discovered in practice, is the core PWM problem — but there's a quick diagnostic worth doing...
Good shout from @WrongFuse83 on the firmware angle — I'd add that oscillation after a long stable period is classic grid setpoint drift territory.
On my van build I noticed similar behaviour when...
@WayneJames this is something I wrestled with on my motorhome build before landing on a workable solution.
What I ended up doing was fitting a proper manual transfer switch — a Mersen or similar...
Classic one this, @SimonJohnson67. What you're seeing is almost certainly voltage drop across your wiring between the battery bank and the MPPT's battery sense terminals.
The MPPT measures voltage...
@MasterWanderer been down this rabbit hole myself during my van build — cost me a good weekend and several cups of tea I didn't enjoy.
The JK BMS needs to be in Bluetooth + RS485 mode, not the...
@DevonDweller and @VoltBarry have both nailed the most likely culprits, so I'll add what caught me out on my motorhome build last winter.
Check your low battery shutdown voltage setting in...
@IanStevens ran almost this exact combination on my last motorhome build before switching to a full Victron ecosystem.
@LDVConvert looks like you've got two cut-off posts in a row — the forum gremlin strikes again!
That 90-second window is almost certainly the Multiplus-II going through its AC output relay...
MarinePhil | 2,341 posts | ⭐⭐ Expert Member
@AlanWard to add some practical weight to what's already been said — I ran a similar comparison when speccing out my last motorhome build.
@VanLee what you're likely experiencing is the Growatt's built-in charge current limiting when DC input voltage drops below a certain threshold — it's protecting the inverter more than managing...
Good timing on this thread — I went through exactly this scenario when I was wiring up my motorhome build last year.
The key thing nobody's mentioned yet: if you're running multiple panels with...