August 17, 20215 yr How can i force the inverter to use more solar (3.5kw available on 1 MPPT) The unit is set to SBU and the two 2.4 pylontechs are set to charge via solar only. It does not seem to use the batteries if there is a shortfall of solar, only if i turn off the utility the system works via the batteries if needed. The system stays in bypass mode 99% of the time. I am going to put in more solar and batteries in the future. I would like to see the system using solar and batteries during peak solar time, say 11 am to 3 pm. Any ideas?
August 17, 20215 yr 5 hours ago, Kieftus said: I would like to see the system using solar and batteries during peak solar time I see that your battery is at 53.2 V, are you using the battery type = PYL setting? If not, you are probably using the Pylontech recommended voltages, which are too high for Axperts. However, I'm not sure that this would result in your problem. 5 hours ago, Kieftus said: The system stays in bypass mode 99% of the time. It's in Line mode, which is what you'd expect for SUB output source priority. In your example with the grid connected, the 509 W of load is mostly (82%) supplied from PV (ignoring losses), so only 100 W or so (plus losses) is coming from the utility. I have no experience with SUB mode, so I don't know if that's normal or not. It may be that in SUB mode, the inverter can't have less than ~100 W coming from utility, though I'd hope it would have better control than that.
August 18, 20215 yr 21 hours ago, Coulomb said: It's in Line mode, which is what you'd expect for SUB output source priority. My apologies, you did say SBU; somehow I was thinking SUB. Sigh. On 2021/08/17 at 8:11 PM, Kieftus said: The system stays in bypass mode 99% of the time. Yes, that is the problem. But with the battery voltage at 53.2 V, which is well higher than the 51 V in setting 13 (Back to Discharge voltage), it should be switching back to battery mode. All I can think of is that your battery, which is very small for an 8 kW inverter, is dipping too low in voltage at the slightest load, and that's causing the inverter to switch back to line mode. Can you measure the voltage at the inverter battery terminals when a moderate load comes on? Preferably with a multimeter that has min and max reading capability. Perhaps repeat the reading at the battery terminals. If the two readings differ significantly, you may have excess resistance in your battery cables (a bad crimp, poor contact with a fuse, etc). Another way to find excessive resistance is with a non-contact thermometer, checking all the terminals. If there is excess resistance, then when running a moderate load from battery power, the place with the excess resistance will heat up several degrees more than other terminals. I suppose it could alternatively be a firmware problem. What main firmware version are you running? Not that I've seen any 8 kW firmware versions.
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