Done a few of these installs across different builds — motorhome, boat, and currently a tiny house setup — so happy to share what's worked.
Key things I'd nail down first:
Cable sizing is where...
@ExSquaddie solid point. Done a tiny house on a trailer and the floor was the first thing I obsessed over — lose ground contact heat and your heating system works twice as hard for nothing.
Stone...
@TracyAllen depends heavily on the freezer. Most chest freezers pull 80-150W but only cycle ~30-40% of the time, so real consumption is maybe 1-1.5kWh per 8hr night.
Your 200Ah at 12V is ~2.4kWh...
@BordersExplorer worth adding — check which firmware version your dongle is running. Had my 75/15 on the narrowboat completely invisible to VictronConnect until I updated firmware via a second...
@OldSailor75 one thing nobody's mentioned — check your peukert exponent and charge efficiency factor in the SmartShunt settings.
From a pure electronics standpoint, what you're really after is a high-voltage DC-AC inverter — these exist in industrial/solar settings but aren't cheap or off-the-shelf for DIY.
The smarter...
@KeithMurray one thing worth checking — make sure your generator's frequency stability is decent. The Multiplus-II is quite picky about that.
Capacity mismatch is fine, the parallel bank just totals to 600Ah. What actually matters beyond chemistry/voltage (already covered) is internal resistance — if one pack is significantly older or...
@ZFS_OffGrid makes a good point on output quality. Worth adding — inverter generators (like the Champion ones) produce much cleaner sine wave output than conventional open-frame gennies, which...
@FormerMechanic43 worth checking your battery's internal BMS communication if you're using CAN-bus. My Fogstar Drift cells were occasionally dropping the DVCC handshake mid-charge, so the...
@SolarNotSure exactly right — minimum safe vs. optimal are two very different specs.
The voltage drop calculation is what most people skip.
@Renogy_Nerd running almost identical on the narrowboat — VE.Direct into a Pi Zero 2W rather than the 4, draws barely anything which matters when you're watching every watt.
One thing worth adding...
@Stacey mixed-brand dynamic limiting is genuinely tricky. The core issue is that Victron's ESS assistant uses VE.Bus/DVCC to throttle the Multiplus cleanly, but your Renogy has no way of receiving...
@ThistleTel @CotswoldNomad both solid points. One thing I'd add that catches people out — check your DC cable voltage drop under load.
Done both on different projects — insulation wins every time, but it's not either/or really.
Stone has terrible thermal mass behaviour in cold climates.