Help with portable solar please

My panels are 24v grid tied panels, 39x65. I have been using a $100 Eco-worthy 20a MPPT charge controller for each panel. I have combined up to three this way for running the little window shaker. I spend 15 minutes or so unloading and hooking them up. Even a pair tracking the sun is more power than we can use and believe me, we try. lol

The panels in the picture are Bosch 245w monos, I've seen them up to 17.75a. I am replacing them with 240w polys this year.

Thanks again all. Hey JiminDenver in the rarified air what size and make are your panels? And what controller are you using? Thanks!

I try to notice as little as possible. ;)

Naturally, all those of us who were in Cubs spotted how the trees in JiminDenver's photo above, have their branches and leaves bunched towards the sun the same way his panels are aimed.

Of course Jim has to wear an oxygen mask, since he is above 10,000 feet there, so he might not have noticed anything! :)

sjturbo wrote:
Sorry was responding to BFL13 and did not see all the additional postings. Thanks everyone! I actually have a 470ah batt bank so I don't think I will find a portable system that size. At this point I don't actually have a good daily usage figure so everything is very hypothetical at this time. I'm just trying to get some idea of others experiences with portable, diy or other.

490w portable. They can pump out 17a+ each all day long.

OP... until you do an energy audit with amp hours used on a daily basis, you are just guessing at your needs for recharging, and the best means to achieve it. Too many camping variables to even come close to making suggestions.

usage, seasons, latitude, shaded or sunny campsite, personal risk levels to theft of charging devices by alien abduction, etc.

You want to recharge for two hours every fourth day with a four-battery bank. Ok, so the recharge will be starting at 50% and to do a 50-90 on four 6s takes about 2.3 hours with a 100 amp charger like my PowerMax 100 or Mr Wiz's WFCO 100 amper or several brands of inverter/charger that can do at least 100 amps. If you insist on two hours max, you need a 150 amp charger and a big enough gen to run it.

So you want to be 235 AH down on the recharge day and 'some solar' every day will supplement your AH usage meanwhile to make sure you don't run out early.

I see "every fourth day" as meaning go three days and then recharge, then do another three days, etc. So your net usage would be 235/3 = 78AH.

In May at 49.3N with a 130w panel I tested and got daily haul of 56AH flat, 70AH tilted aimed South, and 90 AH 'tracking' (tilted and pointed at sun)

Let's pretend you can do that sort of thing with your say 120w portable kit whatever. So pretend you get say 70 AH with yours tilted up against a picnic table and you aim it once in a while.

So if your batteries decline 78AH/day and you were getting 70 in from solar, that means you were using a whopping 148AH a day. Let's get real and say you use more like 70 AH a day. So you might be recharging once a week.

The big thing is your poor 6s are not going to like sitting there for days on end "incompletely recharged" and they will sulfate and die an early death. That is why you must get them to 100% every so often.

Every two weeks at least in this situation. When you are off-grid that is hard to do, since you can't run your gen that long. They need to be 99% before you can even start your overcharge to get them to 100%.

But you can use your solar to do that just by taking the controller out of the loop and going battery- direct. Voltage will rise to the needed 15s/ low 16s to get that done. But how can you run the rig meanwhile? Split bank. Just run the rig on two 6s and do the overcharge on the other two disconnected, and then next chance when the sun is out all day, do the other two.

So you might be able to get by with 120w but I found here with four 6s from April to October with using about 70AH/day the 130w panel I had, even in its contraption, was not quite enough, and I had to use the gen more than I wanted to. It turned out that 200w was about right, so that is what we have now roughly. YMMV

(I don't even bother with solar here from October to March as we camp in the woods when camping then, and days are too short anyway.)

All of which is just meant to give you an idea how to approach the problem using some math to predict likely outcomes. Only you can fill in the correct scenario details.

Sorry was responding to BFL13 and did not see all the additional postings. Thanks everyone! I actually have a 470ah batt bank so I don't think I will find a portable system that size. At this point I don't actually have a good daily usage figure so everything is very hypothetical at this time. I'm just trying to get some idea of others experiences with portable, diy or other.

BFL13 wrote:

sjturbo wrote:
Many of you know my recent setup. Four Crown 6v CR235's. I know this question may be a bit vague but work with me on this. I would like to have a portable solar setup to help with the daily charging so I don't have to run the Honda 3000 as often. So is there a turn key set-up that someone would recommend?

So back to the question here,

A. How much help with the daily charging?
B. How much daily charging is there?
C. How often to run the Honda means:
1. How long each day? or
2. How many days between Honda runs?

What is the plan for keeping the four 6s healthy all year to see where the solar fits in with that?

We have no scenario here in the OP to work with.

Good points BFL13! but as usual answers are a bit vague.
We do not boondock full time so pedestal hookups would sometimes supplement charging through converter and megawatt ps. I would like to be able to boondock for up to a month with just genny power at times to keep the batt bank healthy. I do not want to roof mount or spend thousands to reach that goal. So if it is not possible so be it.
I was just looking for some inputs from those in the know like you.
Thanks:>)
Possible answers to your questions,
A. As much as could be expected.
B. daily charging would be dependent on the solar setup.
C. 1. Hope to run generator max two hours.
2. On forth day

Muddydogs wrote:
Here is my take on portable as I have done both portable and fixed. Last year I purchased a 200 watt solar panel kit from Windy Nation and used the panels as portable, I hard wired the controller and plug into the trailer so all I had to do was place the panels and plug in the cable. The panels worked great but what a pain storing the panels during travel, dragging them out of the trailer and setting them up and then there is always the worry about theft.

When on the road traveling the solar panels aren't doing me any good setting in the trailer and there a little hard to deploy in a rest stop or other quick overnight location. For constant charging with a smaller watt system it just makes since to have the panels out and working the whole day instead of a couple hours at the end of the day after I stopped for the night.

This spring I mounted the 2 panels on my trailer roof before taking off on a week long trip and have to say it was nice to not have to worry about setting up solar and since the panels are fixed I didn't have to worry about adjusting them which I guess is good and bad. The 2 panels kept my battery's charged even with some heater use at night and a little TV time to keep the 3 year old grandson happy just before bed.

This is not to say portable doesn't have its place and I plan on adding a few watts of portable to deploy during hunting season when the sun is not optimal and heater use is at its peak, I also add a couple more battery's into the mix at this time to make sure I have enough battery. For this set up I am camped in the same spot for 2 weeks so set up isn't a big deal.

My conclusions as well. I've purchased 2 x 100w panels, 30a controller, cables, connectors and hardware to install on my roof. I will keep the 100w suitcase portable for supplemental during longer stays.