charge controller wishlist

I was polluting this thread with thoughts as they came to me, so moving them here.

I’ve been thinking about an open source solar charge controller / display project run from raspberry pi or similar, shared on git. Abstract away the hardware details so you can tie it to as $$$ hardware or cheap as one wants.

• • Run multiple charging circuits from the same pi “head”; effectively one charger per panel if desired. SHould be cheaper than buying separate retail units each with their own chips.

  • Folks could write/edit/share MPPT algos or whatever they like. We find problems and address them.  Powerpoint identification could be accelerated (fewer PP tested to find the right one) in changing conditions if we saved some PPT info in another microDB:

    • Our panel’s lab Vmp is X.

    • For the last few days around this time the power output we needed was around X voltage.

    • in a multi-controller group all panels should try the present highest-output PP reported by any panel.

    • When power output is widely varied but changes slowly we probably are experiencing clouds. Try this.

    • When power output oscillates quickly but shallowly (?) we might be under waving branches. Try this other thing.

  • epic configurability

  • data storage in something tiny like sqlite, held for x days

  • analysis and configuration via tiny webserver like lighttp

  • retrieve common default settings for particular battery types, etc

  • Aggregating info might help shed light on how well brands/chemistries of batteries are working. This much load causes this much voltage drop on this kind of bank.

  • export, import, and display settings.

  • system/troubleshooting info summary:  if someone needed help they could cut/paste system info from their web interface into the forum (or pastebin) so we could tell what we are looking at.

  • logging with filterable display

  • wifi/BT interface for the price of a $10 generic dongle.

  • chemistry or preference-based logic:

    • Batteries are below freezing. Don’t charge Lithium.

    • Keep my lithium in the middle 80%

I was in an R/C forum where we banded together to have a custom board built. We had to wait a couple months for enough orders to complete a whole sheet (or whatever it’s called) at once, but they ended up costing $3/ea or something silly. Hardware revisions were easily tracked. It was supah cool.

Looks like Julian Llett on YT has tried something like this with arduino.