Jonathan,
Shoot me an email if you like.
I probably have the parts to do it here.
It can be used as a solar controller, without a dump load.
Basically, it shorts the solar panel and lets the amps run in circles.
Because the solar amps never make it into the battery, there is no need to dump from the battery.
It is sort of Old School thinking in the US and maybe/probably would have code issues with anything grid tied?
It is still a common type of controller in the UK, etc, where they don't use split phase with a grounded neutral (if I phrased that correctly).
It will not harm the panels.
The current flowing through them will only be a couple percent more than into a low battery.
I could figure the part values for you. Should have them here.
There will be some parts standing up flying above the PCB. It'll look just as pretty as every other when the cover is on the box!
I don't know if I have a fet suited for it here. What I would recommend probably costs $12 with their outrageous S&H for 1 TO-220.
Might be able to parallel 2 or 3 more common (alternate spelling: 'cheaper') fets, and use gate balast resistors (free). I am basically against parallel fets, but this setup wouldn't have some of the issues in other setups.
A couple sketches for the 12V version, and a 3rd party link you say? OK, just for you.
This was for 3 smaller PVs, which could use 6A diodes,
This was for larger PV, and a much larger PV, and it shows paralleled fets on the much larger.
I recommended using bridge rectifiers as blocking diodes in his situation.
And a link with pics.
Yours would be about the same, except for maybe the blocking diode and the extra parts flying above the PCB.
The function would be the same.
http://www.fieldlines.com/index.php/topic,129703.0.htmlI disagree with 3.5A not being able to overcharge golf cart batteries.
I have seen a lot of fairly new (less than 6 month old) Trojan 85 and 110AH class batteries ruined with 1.96A PVs (the old 32W Unisolar) and no controller.
I basically got a business started based on that fact. I ordered an SG-4 for a friend, then a couple for his friends, then a bunch of their friends, then people started asking for better PVs...
And this is the snow belt of NE OH. Our BEST month solar insolation is not as good as some places WORST month.
G-