Solar Rv awning -- does it pencil out?

profdant139,

With modern batteries such as SiO2 that are not "destroyed" by partial charging nor deep discharges, a generator becomes even less needful.

I went 5 years with zero generator use. Then I made a mistake and got a generator. In hind sight, I would have been far better off to redo the solar.

I think the charts for my PD 60amp Converter charger with charge wizard says it takes X hours to bring wet cells to 80% SOC and 2 more days to 100%.

It’s why in my untrained mind wet cells and agm work so well with solar if the sun shines and fast charging batteries like lithium work well with fast sources of charge or Big Solar if the sun shines.

noteven,

Recommended charging rate for Li is 0.2 C Maximum may be listed as 0.5 C. Slower charging works well with LI--just stop at 90% state of charge. Li can be charged faster--but cycle life is impacted adversely. The big plus is not having to charge to 100%. Once a month it is good to take them to 100%, to reset the battery management system. Li has too many hoops to jump through for me. I've boondocked at -37 c (-34 f), which makes LI undesirable.

At 80% state of charge, lead acid self limits to 12.5 amps per 100 amp-hours. As a C rate that is 0.125, of course it goes down hill from there as it gets closer to 100%. But lead acid WANTS to be taken to 100% state of charge.

I prefer SiO2 to Li as they enjoy 100% but do not require it except once ever 30 cycles. Their recommended charging rate is 0.25 C

Timmo! wrote:
Well bless your heart StirCrazy...

325 watts @ 12 volts = 27 amps. (The worksheet calculates 300 watts = 25 amps)

My Honda generator produces 133 amps (this has not changed).

Yes the table may be a decade old, but that does not change the accuracy of the breakeven results...5.4 years if the generator is used 1954 days.

How many years do you calculate as your breakeven number?

fills my battery every day I use an average of 80 - 100 AH and I didnt have to but a generator which is 2400 bucks up gere for a honda 2000. watching the amp outputs when I first put it on I could average about 168 AH replaced a day, on a real sunny day close to 200AH and on a rainy day that is dense overcast about 60AH. I also dont have to bring gas, no maintenance.. I would say I broke even the first camping trip where I could use my inverter freely and didnt have to worry about the batteries, but that was just a satasfaction thing, in reality well befor a year... my batteries are full by say 12 to 2pm at the laitest and the rest of the day there doing there equalization or offsetting any other 12V use so they are still at 100% when it gets dark

I think a comparason like this is realy kinda silly, they dont compare. if your buying a generator it is more of a incase thing, or a I want to run my AC thing and I cn get that. I wouldnt turn down a built in genny in my next camper, but I would probabmy never use it inless I was camping in another heat wave and needed the AC.

if you buying solar it because you dont want to carry fuel, load/unload a genny, have noise, or think about it.

trying to pass things off using pricing that is way way out to lunch just to make it sound better or justify why you have a genny is just as ignorant in my opinion. use real numbers and real stats. if you take your rv converter size thats the most charging you can get, take the more strictor campground generator policys for how much you can run it and get proper pricing and comparesons then I'll buy it but its hard to put a paid off pricing on anything.

I guess with my solar, I could look at how many times I was boon docking instead of being plugged in to calculate it if thats the case it paid for its self in about 15 nights, or 1/4 of my camping year this year as this was the first summer I realy used it.

profdant139 wrote:
If I were entering data on that spreadsheet, I would need a separate column for an intangible cost: the noise and smell that accompany generator use.

Using propane as generator fuel greatly reduces exhaust odors - The primary combustion byproduct is just water vapor.