2205S solar panels vs. battery disconnect

[Aussieguy]

It should be your state of charge SOC


You have lead acid ... so 100% your voltage should read 12.6v
50% = 12.06v
for lead acid voltage is a good indicator of SOC
https://www.rvtechlibrary.com/battery/bat_volts.php

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If you change to lithium you would need a better method ....
either a shunt OR a bluetooth enabled battery that will have it's SOC

[Bob.n.Denise]

Aussieguy - Just to make sure I’m tracking. The data shown on the ‘23 2205S Go Power panel accurately reflects my current Interstate 12V deep cycle marine/rv batteries. But if I swap them for lifepo4 batteries, I’ll need something like the Victron energy battery monitor BMV-712 Smart to show true numbers for the lifepo4 batteries?

[18LT]

I can't answer your question directed towards Aussieguy but I might be able to offer some insight into your GoPower solar charge controller.
It uses voltage to show an estimated percentage of charge. Under a heavy load like when the inverter is on and under load, the percentage of battery charge shown on the GoPower display will be considerably lower than the battery's actual state of charge.
In general, the battery's voltage can only be used as it's state of charge when the battery is at rest.
A state of charge meter like mine or the Victron counts the watts passing through the shunt. So one fully charged 100ah lifepo4 battery, which has 1280 watt hours (I think. Someone correct me if I'm wrong), will show 100% on the Victron, and as watts are consumed the counter will track the discharge and the percentage number will read lower. As the battery is charged, the counter will track the energy being returned to the battery and the percentage will increase.
Now that I've totally confused you,,,,,,,,,

[Bob.n.Denise]

That actually make a lot of sense. Thanks for the info.

[18LT]

Originally Posted by Bob.n.Denise

That actually make a lot of sense. Thanks for the info.

Thanks. Sometimes the stuff in my brain doesn't go to my fingers, to the keyboard and onto the screen correctly.
Sometimes even I don't understand this stuff after I type it. After all, I AM super old.
We had a nice time camping in our 2205S last week. I'm really enjoying doing breakfast on the griddle that came with it.
You need to try Bisquick Shake N Pour. Pancakes don't get much easier than that.

[Aussieguy]

18LT said it right...
lead acid... voltage is a good indicator of SOC


Lithium better to have a shunt
OR ... some batteries have Bluetooth ... you can get a SOC via your phone APP


You only need to gauge your state of charge (SOC) for a little while
to make sure your setup is able to charge up the batteries to your needs


You don't want to get obsessed watching your batteries like a hawk.
when you find your balance between panel size and battery usage, you'll probably rarely look at your SOC if the sun is shining.


Rainy times you'll probably look more often



Aim for a battery capacity that gives you 2-3 days of usage
and panels that will replace your daily usage within 4-5 hours

[Aussieguy]

Originally Posted by 18LT

You need to try Bisquick Shake N Pour. Pancakes don't get much easier than that.

No Fair........ I have to loose more weight!

[Bob.n.Denise]

I look forward to building out our power needs on this new 2205S.

Long pole in the tent will be AC. My wife needs AC at night, so we currently travel with a Honda 2200i. But it’s not a perfect solution (elbow in ribs at 3am). Would love to have an electrical system in place that gets us through the night. Then recharges as we travel to the next harvest host location.

[18LT]

Originally Posted by Aussieguy

No Fair........ I have to loose more weight!

They're good enough to munch on without syrup. No joke.

[18LT]

Originally Posted by Bob.n.Denise

I look forward to building out our power needs on this new 2205S.

Long pole in the tent will be AC. My wife needs AC at night, so we currently travel with a Honda 2200i. But it’s not a perfect solution (elbow in ribs at 3am). Would love to have an electrical system in place that gets us through the night. Then recharges as we travel to the next harvest host location.

Actually, I built our battery bank/inverter-charger/solar charge system so that we can run our AC at night. You'll need more battery and a bigger inverter but it can be done without a generator pounding away outside the camper.
Battery bank and inverter-charger are mounted in the pass-through compartment.

[TitanMike]

Originally Posted by 18LT

Actually, I built our battery bank/inverter-charger/solar charge system so that we can run our AC at night. You'll need more battery and a bigger inverter but it can be done without a generator pounding away outside the camper.
Battery bank and inverter-charger are mounted in the pass-through compartment.

One thing worth noting, running an A/C at night from inverter and battery bank is easirevthan running it during the day.

No sunlight beating down on the RV adding to the heat load.

Still hard to get past the issue of recharging. Need a big converter/charger if charging from a generator and or lots of solar.. Same for a DC-DC charger when recharging from tv or coach alternator.

In short, it's a big investment in time and treasure.

[18LT]

How true on all counts.

[Aussieguy]

getting enough battery to run a standard rooftop a/c will be very difficult and expensive.
you would need about a 100ah battery for each hour of a/c use.
So 8 hours would be around 8 batteries = $2400

daily charging such a large bank will be a handful , you wont get enough panels on your roof !

if you could get 60amps of charging (720w @12v) it will still take 13 hours of charging
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a lot of people have reported good results with a 120v mini split air conditioner
with inverter control of the compressor
they can use around half the power or a std rooftop
they also claim it is much more quieter while running the a/c

may be worth your while to research if one can fit to your layout.
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my thoughts on them.
If my rooftop unit died... I would look at mini split

Right now I use a 3500w inverter generator because i get more tank capacity
IMHO it is a bit quieter as it is not much above idle..
my smaller generator runs higher revs and needs a softstart


I try not to go anywhere where I have to have the a/c unless there is shorepower.


I set it at 77deg it keeps the humidity down
and we have gotten use to the higher temperature setting
we use it at the house a/c too

[DJ252]

Originally Posted by Bob.n.Denise

I look forward to building out our power needs on this new 2205S.

Long pole in the tent will be AC. My wife needs AC at night, so we currently travel with a Honda 2200i. But it’s not a perfect solution (elbow in ribs at 3am). Would love to have an electrical system in place that gets us through the night. Then recharges as we travel to the next harvest host location.

AC at night, all night, is gonna be a tall order, without outside generation. The battery bank will have to be substantial. I know of an 810ah system that couldn't do it.

[18LT]

Our present system consists of;
One 300ah lifepo4 battery
Two 100ah lifepo4 batteries
3000/9000 inverter-charger, 85 amp charging capability
Four 190-watt panels on the roof
60-amp mppt charge controller
With the battery bank at 100% we can run the roof air at night for 8 hours, with the air actually running 20 minutes of every hour, outside air temp at 75 degrees and the thermostat set at 72 degrees. This is our camper's actual performance.
Replacing the factory installed Coleman Mach thermostat with a digital thermostat reduced our roof air's run time dramatically. It holds the inside air temp within two degrees, which is way better than the Coleman thermostat. I also installed an easy start.
As mentioned in one post, the batteries need to be returned to 100% the next day. Best case scenario, our solar charge system and tow vehicle's alternator might be able to do that if we were traveling the next day but if we were to camp offgrid for several days we'd need to run a generator to recharge batteries AND run the air during the day.

[chriscowles]

Originally Posted by Bob.n.Denise

... If this set up proves to be inadequate in supporting our quasi boondocking, what's next step? Add a portable solar kit (e.g. Renogy 200W briefcase) or replace batteries with Lithium? ...

I think the 200W of panels will prove inadequate, especially with FLA batteries, the reason being they're slow to charge and you can use only ~50% of their capacity on each cycle without compromising their expected life.

I recommend upgrading to LFP first, then adding a solar briefcase later if needed. If your charger/converter isn't Li-aware, it's not a hard requirement to upgrade that because the solar charge system will top off the Li batteries. Just make sure your solar charge controller(s) are adjusted to charge LFP rather than FLA.

[chriscowles]

Originally Posted by Bob.n.Denise

I look forward to building out our power needs on this new 2205S.

Long pole in the tent will be AC. My wife needs AC at night, so we currently travel with a Honda 2200i. But it’s not a perfect solution (elbow in ribs at 3am). Would love to have an electrical system in place that gets us through the night. Then recharges as we travel to the next harvest host location.

I recommend something quieter than generators but, if you conclude that's your best option, consider getting a 2200i Companion and run them in tandem. Together, they'll run quieter and probably longer, not having to ramp up (as much) to handle the load when the AC cycles on. Also, consider an extended run fuel tank kit to get you through the night.

Being businesses, do Harvest Host sites not mind your running a generator all night? Most campgrounds forbid it. A Boondockers Welcome host might forbid it, or leave a bad review. That could hurt your chances of getting other sites.

[18LT]

Originally Posted by chriscowles

I recommend something quieter than generators but, if you conclude that's your best option, consider getting a 2200i Companion and run them in tandem. Together, they'll run quieter and probably longer, not having to ramp up (as much) to handle the load when the AC cycles on. Also, consider an extended run fuel tank kit to get you through the night.

You mean Harbor Freight's inverter-generators aren't whisper quiet? I'm shocked! (Not really.)
I've never seen one of those fuel kits. That's pretty slick. I wonder if it fits the A-iPower 2300 inverter-generators. I have one and I'd like to get a second one to parallel them.

[Bob.n.Denise]

Chriscowles – We always ask our harvest host (winery or golf course) about pets, slides & generator. Have never been told no, plus we wait till the business is closed before starting the Honda inverter generator. Most are outside residential neighborhoods. I can understand “Boondockers Welcome” sites having an issue with noise (or at least their neighbors).

We have both 2200i and 2200 ic. Used to run linked until I installed a soft start on 1 of the 2 ACs. Believe out new trailer (’23 2205S) has a soft start on its one AC as OEM. Need to look at extended fuel kits as one 2200i would run out of fuel in the middle of the night.

I wonder if something like a Portable Power Station (EcoFlow, BLUETTI etc.) would be better than a gas generator?

So much to learn…

[bikendan]

Originally Posted by 18LT

You mean Harbor Freight's inverter-generators aren't whisper quiet? I'm shocked! (Not really.)
I've never seen one of those fuel kits. That's pretty slick. I wonder if it fits the A-iPower 2300 inverter-generators. I have one and I'd like to get a second one to parallel them.

HF's Predator 3500w inverter generator is pretty quiet. It's quieter than their 2000w inverter generator.