ironcast

Inverter is MUST 3000w 24v, batteries are 2.7kwh 106ah SVOLT LifePo4 with only built-in BMS. 1. Charge batt1 to bulk & position Batt2 in-place (next to batt1) 2. When Batt1 1 hits bulk, turn inverter soft switch off, then turn batt1 off (its built-in breaker) 3. Remove - then + from batt1 and connect + then - to batt2, then turn batt2 on (its breaker) 4. Turn inverter soft switch on and charge batt2 to bulk 5. When batt2 is charged to bulk, turn inverter soft sw. off, then Batt2 off (its breaker) and disconnect - then + 6. Wait. Hours. For Batt1 and Batt2 to both get to equal rest (resting differs per manufacturer, e.g. 26.5v 0.1v/0.2v/0.3v diff) 7. Connect Batt1 to inverter then turn batt1 on. Turn Inverter soft-switch on, wait 1 min for inverter caps to charge, turn inv off, then disconnect batt1 again. 8. Quickly: Turn both batteries on (their respective built-in breakers) & connect + first then - from Batt2 to Batt1 + and - 9. Batteries are now parallel but disconnected from inverter - leave both batteries on 10. Connect + from batt1 and - from BattB to inverter and turn inverter soft-switch on. 11. Clean up urine puddle The above is considering no available resistor / 220v 50w/100w bulb for pre-charge. Step 7 is an attempt to pre charge.

Thanks! USR mode gets to bulk then drops to float - Li mode hits bulk and stays there for hours with 0.5a and the MPPT icon off. I assume it's just the nature of the cheapness of this thing. Changing from USE back to Li immediately sends back to bulk... I imagine the BMS has long since disconnected the battery from it's charging cicruit and the inverter is still pushing 28v lol.

Hi All, without overomplicating the question: how long can I leave my 25.6v 106ah 2.71Kwh SVOLT *No Comms* in Bulk mode? 4 hours / 2 hours / 8 hours? And, after X amount of time in this voltage, will the built-in BMS cut-off the charge? *Yes, my MUST has the float bug, yes, I've worked-around it, mostly.

Hi, my MUST pv1800 3kw/3kva Inverter reads my newly-installed (2 days) SVOLT 25.6v 2.71kwh 106ah (No COMMS but built-in BMS, naturally), at 0.5v higher than the batt. actual voltage. Load or no load. Yet, measuring at both inverter terminals (inside) and the battery terminals are identical, and show true voltage. So the route from battery to inverter is fine. I.e. MPPT PV Screen shows 27.1 & Battery screen shows 27.6, true is 27.1. As the MPPT PV Screen shows the true voltage, to ensure correct values I had to offset the Bulk, Float, Cut-Off etc. by 0.5/-0.5 & observed actuals did reflect, thus - this was to success. I've not set the max charge current to above 20a yet. That, I will do carefuly & will measure things whilst doing so, though the built-in LifePo4 BMS correctly shuts the battery off if a too-high-a-value is set. The inverter never did this with previous banks of SLA's of various combinations in LEA, GEL & USR modes. I've reset the inverter several times to no avail. The battery screen still shows +0.5 higher but MTTP screen shows actuals, and, the various configs (Bulk, Float, CutOff, etc.) appear to respond to the battery value & not the 'MTTP charge controller screen' value, thus my workaround to offset voltages to compensate - shows correct voltages on the MTTP screen, whilst the +5 incorrect voltages remain on the Battery screen. Reset battery BMS switch - yes. Have run 1 x cycle thus far. HUH.jpg?