TC off the grid, and solar question

[towpro]

when we get the new camper, we might try doing 2-5 nights without electric this fall out at the beach.
Sure I will have a generator but I only want to use it if AC is needed.

So looking at what many on this forum have printed about there system, but this brings up a question. The solar charge co9ntrollers are a little different.
Some have Load terminals
Some have 2 battery outputs.

Does the 2 battery outputs treat each battery different? or is it just a convention way to wire 2 batteries.

The ones with Load terminals: If its a 30A controller, I assume that means don't put more than 30A solar charge load through it, but does it also mean the load side is only good for 30A? (I understand you don't wire the on-board AC/DC charger through this).

TC content:
How much current does a TC run for just day to day living (no AC inverter for microwave).
Refreg on propane, hot water on propane, couple LED lights, maybe heater starts, will the load ever go over 30A?
The only High current stuff I might run is a small inverter to run a Satellite receiver.

[pianotuna]

Hi,

I have 66 US gallons of fresh water. The pump can drain that in 30 minutes. The pump draws 8 amps, so the total use can be no more than 4 amp-hours. That's about what a single 1156 bulb uses in 2 hours, so it is an insignificant draw.

[2oldman]

towpro wrote:
The only High current stuff I might run is a small inverter to run a Satellite receiver.

@ about 12a @ 12vdc, that's not high current. High current is a microwave.

[towpro]

The original question:
Do I wire camper load (and not camper changer) to load terminal? or leave them empty? I expect by using load terminals I can view current amperage usage the RV is using on a display. And If its a 20A controller, that that mean the current between battery and Load is limited to 20A?

If it is a controller with 2 separate battery connections (2 batteries) does it treat each battery different?
example, every 25 days it does a charge to knock sulfation off the plates, but a single 100w panel might not have enough current to run de-sulfation mode on 2 batteries at the same time.

[Tiger4x4RV]

towpro wrote:

How much current does a TC run for just day to day living (no AC inverter for microwave).
Refreg on propane, hot water on propane, couple LED lights, maybe heater starts, will the load ever go over 30A?
The only High current stuff I might run is a small inverter to run a Satellite receiver.

Don't forget the water pump.

[gpascazio]

Those two links are great. Study them closely. I would add another to a supplier of solar panel systems. AMSOLAR.COM I installed a 300w system. Their systems are complete, everything is included in the kit. I have had the system installed for two years and it has worked flawlessly. What limits our boondocking now is our freshwater supply instead of our battery capacity.

[pianotuna]

Hi,

Solar systems may be thought of as a battery charger. I.E. they only fill up the battery, and don't often power anything directly.

The load won't go over 30 amps but that is a moment to moment measurement. What you want to know is the total amp-hours that are used in a 24 hour period.

The load terminal on a solar controller are used to switch on a light at night. The battery terminals are where the charging is regulated. So you can ignore the load terminals for the most part.

The 30 amps is the rated output to the battery terminals.

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT. What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.

One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!

Solar Spread Sheet by N8GS

For a nice explanation of solar, try this link:

Golden rules of solar