"Larry Jaques" wrote in message
...
On Sun, 5 Nov 2017 18:52:52 -0500, "Jim Wilkins"
wrote:



Finding the MPP with the DPS5015 shows me how much more current an
MPPT controller would give, compared to a direct connection from the
panel to the battery as with a PWM controller. I've read that an
MPPT
controller isn't cost-effective for arrays of 200W or less, or for
trickle charging batteries whose voltage is already close to the
MPP.

Yup, but they can give you a whole lot more usable power on larger
systems. I intend to expand this 1kW system to 6kW at some time in
the future, so I should probably buy that Outback before more
panels.
So, with the new 100w panel, are you now only up to 145w
(theoretical)?

Here is a good analysis of PWM vs MPPT:
https://www.victronenergy.com/upload...WM-or-MPPT.pdf
On Amazon PWM controllers go for $20 or less, MPPTs for $100 and up.

I use a metered adjustable linear regulator to top up and mildly
equalize batteries with power from my HF 45W kit. As they near full
charge the batteries draw less than the full current the panels can
provide and easy voltage adjustment becomes more important than
controller efficiency. 1.5A is enough for the marine batteries, 1.0A
for the vehicles. A Schottky diode in the regulator keeps battery
current from feeding back if I step on the wires and crush them
together against a stone.
-jsw