MEGAWATT 60-AMP INTRODUCTION

pnichols wrote:
Thanks much for your additional off-topic comments ... I trust that Mex is not too upset with us (me -> it's my fault).

Your comments pretty much confirm what I thought regarding an optimized portable system:

- Wire the two hinged 60 watt panels in series to both pump up the voltage and cut the current in half so as reduce wire resistance losses,

- then optimze use of the higher incoming voltage by mounting an MPPT controller right at the batteries,

- and stay away from roll-up flexible panels because you need a frame for them to aim them which negates compactness ... or forget aiming them and then run the risk of people/animals/ants stepping on them if you merely lay them on the ground.

Your comments did not (that I noticed) address the age-old question of "poly or mono?".

Thanks again .... and I apologize, Mex!

My portable panels are mono crystalline. Mono has a smaller foot print, per watt. Important with portables. Mono yields 17.0V at Isc. 17 V at Isc means less voltage overhead loss versus 18V or 19V Isc. Since the overhead loss is lower, the amperage yield per watt must be higher to get the same amount of watts per panel.
Since with portable, you aim directly at the sun, shade or diffused light benefits from poly are pretty much negated. If you camp in the desert, where it's sunny almost all the time down in Quartzsite, mono gets the edge with all the sunshine, on most days, in terms of amps harvested for size of solar panel foot print. It weighs 27 pounds.

You'll spend at a minimum $90-100 for a cheap chineseium MPPT controller. The PWM on there yields 6.6 to 7 amps/hr if the battery starts being charged after 10 am in the morning and is at a 50 to 60% SOC.

I somehow doubt there is more than .6 to .7 Amp to be gained, per hour, going with an additional $100 MPPT charge controller. .7 Amps times 6 hours of charge time in the winter in Q is a net gain of 4.2 amps into your battery, per day... maybe 35 amps to 39 amps.

Winter in Q is a worst case scenario, short days and long nights. Might be better to run the generator for an hour in the AM to put 15 amps back in the battery, and let the solar do the rest, the rest of the day.

In the spring, summer and fall, the days are longer and the nights are shorter, less draw on the battery and more amps harvested per day. Probably best to run the gen just first thing in the am in the 3 or winter months, Nov- Feb. for a bit.