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LiFePO4 300w controller:




Since I can't easily patch my 100AH LiFePO4 battery in with my main grid (which is running SLA batteries)
I decided to get a small controller that's designed specifically for lithium batteries. I intended to just hook
up a set of maybe four of my usual 100w panels to it, and use it as a self-contained power system for one of
the satelite stations on Field Day.

I found a controller that's rated 300w but has a panel Voc max of only 50 volts. This is more than you see
on most non-home-grade controllers, but still prevents me from placing my usual four panels in series because
the Voc there will be around 90 volts. So I made a series-parallel combiner to parallel half the panels, to
keep the voltage within the controller's limits. Four 100w panels will Voc around 44v and max out at 300w.

This controller uses surprisingly small wire though, considering its going to be handling close to 20 amps.
I'd rewire it, except that the whole thing is potted and sealed. So I guess the wires will just get warm.
I also replaced the yellow PP housing with a green one, to match my standard for solar ports.

Standby current is just 1mA.



300w LiFePO4 charge conrtoller ($44 at eBay)


LiFePO4 combiner (in combiners)

1 top	2 bottom	3 in use, 273 watts	Impulse Lith MPPT 1	Impulse Lith MPPT 2	Impulse Lith MPPT 3

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