diy solar

diy solar

Female newbie! Honest opinions and advice please!

Inverter 2000W
PV panel 40W
battery 100 Ah

Seriously under-paneled.

Battery - is that FLA "flooded lead-acid" wet cell? Or sealed, like AGM or Gel?
If FLA, it wants 12A, so 150W or more of panels for a 12V battery
If sealed, I'm not sure how slow a trickle charge is OK, but can probably take 10A, maybe 20A.

Expect 5 to 6 effective hours of sun in the summer, 1 or 2 in the winter (check an "insolation" website for your location.)
6 x 40W = 240 Wh, 1 x 40W = 40 Wh
Compare that to battery, 12 x 100 = 1200 Wh.

The inverter probably wastes 25W just sitting there, so if turned on for one hour, there goes 25Wh. Left on 24 hours per day, 600Wh drained.

Check out Craigslist for local used or extra PV panels.
You might pay between $0.10 and $0.50/watt.

Catch is, most big cheap panels are 24V or 36V
You have a PWM charge controller, which needs a 12V panel (Vmp in the 17V to 20V range.)
To use the higher voltage panels you would need an MPPT charge controller


At this point I would recommend she scrapes the PWM and get a cheap MPPT 12/24 volt SCC that can take a larger panel (higher voltages input) -- and then like you said - search craigslist for a single good size panel that can push probably 250-350 watts... that will keep the battery charged to full almost all the time which AGM's like plus allow her to add more and more lights in the future ...
 
Hmm, "Leisure battery" "sealed maintenance free"
Me thinks that is FLA. Would this type want 0.12C charge rate? If so, 100 Ah --> 12A charge should be set in charge controller (or model delivering about that current selected.)

"200 cycles" "850A starting"
This ain't no "Deep Cycle" battery, so avoid draining it. OK to run a small light overnight. Best use is surges of power for inverter, while sun is shining so it charges right back up.

(That's where I would prefer a charge controller that delivered 12A when there are no loads, more to supply loads but never more than 12A into battery.)

 
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