I would like to hear some comments and suggestions.
In July 2017, I made some progress on understanding the settings in the MS SS MPPT 15L solar controller. I then modified several settings which move towards a more automatic charging approach. I use two overnight low Voltages(OLV), 12.6 and 12.4, as triggers . These two OLVs drive three charging profiles for the day.
Each AM, the controller executes a start up process(charge_state=4) when the charge_state switches from Disconnected(3) to Bulk(5). This seems to be driven by the appearance of Array Volts. At this time, the day's profile is established.
I set up three profiles.
1. Storage - there is a one hour timed ABS stage before float because the OLV was 12.6 or above.
2. Extended Abs - there is a two hour timed ABS stage before float because the OLV was between 12.6 and 12.4.
3. Cancelled Float - there is unlimited ABS because the OVL was below 12.4.
Now we can see this working in a graph.
This covers 7 days; Jan 5 - 10 in full and Jan 11 up to 9:40AM.
Jan 5,6 - this is a perfect definition of Storage in good solar; One hour of timed ABS.
๐Jan 7 - Bad solar day! The controller was stuck in Bulk and never made it to ABS.
Jan 8 - Good solar. The controller AUTOMATICALLY adjusted ABS to 2 hours because OLV dropped below 12.6(not shown).
Jan 9,10 - AUTOMATICALLY Adjusted back to Storage with good solar.
Jan 11 9:40 - I am looking out at the bad weather and predicting a repeat of Jan 7. Tomorrow's forcast is Sunny and the controller will AUTO-correct the same as it did on Jan 8.
Here is a summary of possible profiles since I started logging in May 2017.
Count Profile Avg Min Volts
---------- ------------ -------------
14 Cancel Float 12.26
105 Extend Abs 12.53
99 Storage 12.68
I switched to the SSMPPT15L because the programming features greatly exceed the TRISTAR 45 PWM.
I must shout out to MS for patiently answering many questions, thanks guys!
HTH;
John