westvandude
New Member
- Joined
- Jan 11, 2021
- Messages
- 23
I have two SMA 6048 sunny islands off a 24.5kwh nissan leaf pack gen2 modules. Anyhow, everything was working fine until we had a power outage 14hrs long and the system ran for about 7hours and quit depleting the battery. I didn't have the ABB disconnect relay/breaker wired up for disconnect by the bms but the bms did shut down the sunny islands with it's RS485 connection. When I measured pack voltage it was about 47.4v which isn't crazy low.
Anyhow, I stuck a small 5A 60v lab power supply to the pack for an hour and brought the voltage up slightly so that the bms was not flashing red led and beeping alarm.
I restarted the sunny islands as I had to power my laser printer briefly to get an invoice printed. Had a generator running separately for fridge/freezers (not connected to my system). At this point the sunny islands showed 1% SOC.
Yes... I know, I need to wire up a transfer switch and connect DigIn on the islands, etc and possibly get a larger generator or diesel etc. Also need to connect one of my 41series 6kw gridtie inverters to the secure loads panel as well as changing settings on the islands and the gridtie to offgrid. I've got the grid code to do that. Boy these things have way too many settings lol.
Once power came on the SOC went up to 12% rather slowly. Eventually landing on 14%. It took me a while to get my old laptop going with the rec-bms software application and then guess at the COM settings and all the junk (drives me nuts that it's not intuitive!!).
So I first thought why the heck is it stuck at 14% SOC after like 6hrs of on-grid recharging? Once I got into the bms and checked voltages, etc everything was charged up to my orig settings of 3.9v per cell and I upped the END of Charging voltage from 3.9 to 4.0 and eventually back to 3.95 to watch the charge current. It indeed did ramp up to 50A and then down to 20A. So my settings in the sunny islands are essentially 60A or whatever is the higher setting for charging current ongrid. I had thought that the sunny islands were limiting charge current. That wasn't the case.
So at the end of the day, the sunny islands and the bms are working correctly, except the SOC is not showing 100% and I'm not sure how to fix that. I've emailed REC. Lets see what they say.
Figured I'd post this up just because I haven't seen this issue posted anywhere before. Up until this point the pack was always floating at 100% SOC except for one power outage that was brief maybe an hour, which didn't screw up the SOC reading.
On a side-note, one of my kitchen lighting breakers is an arc-fault unit and that has gotten real flaky since running straight off my generator (which wasn't holding rpm super accurately - stupid carburetor!) I'm thinking the generator may have pooched it. Personally I think the arc-fault breakers and gfci's as well as child-proof outlets that push your plugs out over time are straight up TRASH.
Anyhow, I stuck a small 5A 60v lab power supply to the pack for an hour and brought the voltage up slightly so that the bms was not flashing red led and beeping alarm.
I restarted the sunny islands as I had to power my laser printer briefly to get an invoice printed. Had a generator running separately for fridge/freezers (not connected to my system). At this point the sunny islands showed 1% SOC.
Yes... I know, I need to wire up a transfer switch and connect DigIn on the islands, etc and possibly get a larger generator or diesel etc. Also need to connect one of my 41series 6kw gridtie inverters to the secure loads panel as well as changing settings on the islands and the gridtie to offgrid. I've got the grid code to do that. Boy these things have way too many settings lol.
Once power came on the SOC went up to 12% rather slowly. Eventually landing on 14%. It took me a while to get my old laptop going with the rec-bms software application and then guess at the COM settings and all the junk (drives me nuts that it's not intuitive!!).
So I first thought why the heck is it stuck at 14% SOC after like 6hrs of on-grid recharging? Once I got into the bms and checked voltages, etc everything was charged up to my orig settings of 3.9v per cell and I upped the END of Charging voltage from 3.9 to 4.0 and eventually back to 3.95 to watch the charge current. It indeed did ramp up to 50A and then down to 20A. So my settings in the sunny islands are essentially 60A or whatever is the higher setting for charging current ongrid. I had thought that the sunny islands were limiting charge current. That wasn't the case.
So at the end of the day, the sunny islands and the bms are working correctly, except the SOC is not showing 100% and I'm not sure how to fix that. I've emailed REC. Lets see what they say.
Figured I'd post this up just because I haven't seen this issue posted anywhere before. Up until this point the pack was always floating at 100% SOC except for one power outage that was brief maybe an hour, which didn't screw up the SOC reading.
On a side-note, one of my kitchen lighting breakers is an arc-fault unit and that has gotten real flaky since running straight off my generator (which wasn't holding rpm super accurately - stupid carburetor!) I'm thinking the generator may have pooched it. Personally I think the arc-fault breakers and gfci's as well as child-proof outlets that push your plugs out over time are straight up TRASH.
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