Help with Sunny Island inverter

System

I could use help understanding a few things about our system:

3K of panels
Sunny Boy
Sunny Island 5048U
16 Rolls S-530 Batteries (48v, 800Ah)

- So the battery State of Charge (Soc) % meter on the Sunny Island (SI) is quite erratic, (we never could get the Tri-Metric to work right) so that between 8pm and 8am the next morning, the Soc can drop 8%, or it can drop 17 or more %, with the exact same overnight load on the system. As an occasional thing, this could be due to internal adjustments of the metering algorithms... but it varies every single night, so it's hard to judge our usage to keep the gen from turning on.

- The typical charge mode is "boost", but as of late this mode has frequently only charged the batts to less than 85% Soc. What this means is that by the next morning we are often getting close to the generator auto-run set point of 60% Soc after a full day of sun.

- These symptoms began in earnest about a month and a half after an EQ charge.

- We keep the batts well watered.

I am fairly new at this game so any suggestions would most likely be helpful,
Thanks

mike95490

Re: Help with Sunny Island inverter

My first guess is some panels may have gotten sick ? Any way to record the daily volt / amp / total from the PV array to the batteries ?

Anoher guess is any large loads running in daytime, that will consume your power before it gets to the batteries?

mike95490

Re: Help with Sunny Island inverter

PS & fire up the genset now, before your batteries sulfate - get them above 80% before noon, and see if the solar will top off

Cariboocoot

Re: Help with Sunny Island inverter

By my estimation you've got about 1/2 the panel you need to really charge those batteries.
Charging 80 Amps @ 57 Volts = 4560 Watts, less a "typical" efficiency derating of 77% = close to 6 kW array. Remember that charging is net of what goes in from the panels minus what goes out to loads. Looks like you have just enough panel for the 5% minimum recommended rate with no loads.

But that would be in a purely off-grid situation and usually the SunnyBoy/Island set-up is for grid-tie with battery back-up. Not sure it's a good choice for purely off-grid.

Like Mike said, get the batteries charged now and check them with a hydrometer. It may already be too late.

stephendv

Re: Help with Sunny Island inverter

Hi,

I also have a 5048, but no solar yet. Can't comment on the SoC reading, mine has been working fine with the light loads I have and has pretty much agreed with the hydrometer readings. The SoC depends on having entered the correct battery capacity, and this needs to be given for the C10 rating of the battery. For your Rolls battery it should be programmed as a 680Ah capacity in the sunny island.

gunther wrote: »

- The typical charge mode is "boost", but as of late this mode has frequently only charged the batts to less than 85% Soc. What this means is that by the next morning we are often getting close to the generator auto-run set point of 60% Soc after a full day of sun.

You could check the boost settings and make sure that it's spending enough time in absorb mode. 3-4 hours should probably do it.