What gets me every year without fail is how fast it compounds. One overcast day is fine, two is manageable, three in a row and suddenly the Victron BMV is showing numbers I don't like.
My garden...
@RelayNomad one workaround I've seen used (and briefly considered for my garden office before going full DC-coupled) is running the microinverter AC output into the Multiplus II's AC-in, letting...
Good shout from @VivaroWanderer and @12V_King on the VEConfigure side, but nobody's mentioned Dynamic Cut-off yet.
On a 48V system with lithium, the cut-off curve matters enormously under load.
@Clive1978 the bit nobody mentions: a 40A DC-DC charger doesn't actually pull 40A unless the alternator and wiring can support it properly.
@NorfolkDweller had this on my garden office setup when I first commissioned it. Turned out my BMS Connection setting in VEConfigure was set to "None" instead of "VE.Bus BMS" —...
GoldenSocket | Posts: 1,203 | Location: Array
One thing nobody's mentioned yet — check your absorption time setting.
@WattVicky and @MarineGeoff have both covered the main points already.
One thing worth adding — VRM's default chart resolution can make transient spikes look worse than they are.
Had exactly this with my 100/30 last summer. Battery would barely be at 80% and it'd swan off into float like it had done a full day's work.
@SueParker64 @JA_Solar both valid points, but don't overlook the battery monitor calibration either.
@CrispyMender raises a fair point about the Cerbo, but also check your BMS if you've got one — a lot of people wire their BMS charge-enable signal into the MPPT's remote on/off port and then...
@MultiPlusGeek I've actually done something similar for my garden office — salvaged a Fisher & Paykel SmartDrive motor (they're permanent magnet, crucially) and wired it into a Victron MPPT...
Good point from @SolarJake on VE.Config — just to add, if the installer used VE.Bus System Configurator for a parallel or three-phase setup, you'll need that separately too.
Worth noting for anyone who finds this thread later — this catches people out every single April and October without fail.
@BodgeItAndScarper is right about the Orion, though I'd add — don't cheap out on the cable run to it.
@RelayDream raises a fair point on comms — and this is where budget chargers tend to fall flat in my experience.