Newbie to solar has questions

[dpickard]

Hi y'all!

Gil is having some medical issues and will be recuperating at home for a while.

I am not comfortable driving the big motorhome to the dog shows alone, so it will sit in the driveway until he is better.

For my birthday this month he gave me a wonderful present; a little used 2017 T@B 320S teardrop trailer in like new condition and a 180watt Zamp solar suitcase.

Now to the issue(s):
The trailer has ONE lead acid marine battery. I haven't attempted to use the Zamp system yet (and probably a good thing) because I have questions that the sales literature doesn't answer.

The trailer has a pre-wired solar plug that says it's solar ready.

I went on the Zamp website and saw a chart that shows the 180 watt suitcase depicted with a sample trailer that has TWO batteries. What will happen if I try to use this with ONE battery? I am afraid to try to use it now until I hear back from experienced folks. Is this too much wattage and will it damage the T@B?

If it IS ok to use, what is proper procedure? Do I have to unplug from shore power or is it ok to leave plugged in to 30 amp while solar charging?

Thanks for any light you can shed on this.
Dianne

 

[HueyPilotVN]

You will be OK.

A 180 watt solar panel system is fine for a single 12 volt RV battery.

Most Solar charging systems have the ability to taper off the charging current as the battery becomes full,

You can also use the charger in your trailer either or both at the same time as it also has the same ability to taper off and just maintain the battery,

Using both is like filling a swimming pool from two hoses.

If you are concerned about how much charging current is going into the battery or coming out as it is used than you can get a battery monitor.

A battery monitor is a gauge that uses a shunt. ( a short section that is inserted in the negative or ground cable ). It uses two small wires to measure the current flow in or out as well as how full the battery is, ( State of Charge or SOC),

Good luck with your new trailer and enjoy it.

 

[dpickard]

Thank you so much for the reply, Bill. It is much appreciated!

 

[Ex-Calif]

Hope Gil recovers fast...

Batteries have "resistance" which limits how much amperage they will accept. Consider it like a pipe - you can only push so much through it.

Bill covered it well. 180 watts at perfect efficiency is gonna deliver about 10-12 amps. A fully discharged battery will take a little more than 20 amps so the solar and charger can both contribute.

So I looked it up. If it's the same one it seems like a quality unit with a built in charge controller and monitor. Expensive little beast though...

 

[SargeW]

If you plan on camping while not plugged in, then the size of your battery comes into play. The bigger, or number of batteries determines how much available power you will have to use. IE if you have a 80 amp battery, you will safely be able to use about 50% of those amp hours. And if you do, the solar will take a while to recharge the battery depending on the amount of sun on the panels.

 

[Tulecreeper]

If you plan on camping while not plugged in, then the size of your battery comes into play. The bigger, or number of batteries determines how much available power you will have to use. IE if you have a 80 amp battery, you will safely be able to use about 50% of those amp hours. And if you do, the solar will take a while to recharge the battery depending on the amount of sun on the panels.

You're going to get our LiFePO4 guru all spun up again.

 

[Isaac-1]

All I will say here is camping with a single battery and a 180 watts of solar, that you had better be a minimalist as that is not a lot of power to run things. On a typical mid US clear day you can expect to get about 1,000 watt hours of power out of those panels if angled for optimal tilt in the spring or fall, a bit more if you readjust them throughout the day. This can in theory fully recharge your single battery if drained all the way during the daylight hours in a single day, if there is no other daytime load (fans, lights, etc running).

As to how much power your battery can provide, you have about 950 watt hours available fully discharging it (which will somewhat shorten its service life), this means you can run a 950 watt load for one hour, or a 95 watt load for 10 hours, etc. Here are some example loads, an iPhone 14 has a 12.68 watt hour battery, meaning you will draw a bit over 15 watt hours total of power to charge a dead iPhone once you consider charger losses. If you have an RV propane refrigerator with digital control board (has LED lights on the front) it will draw between 6 to 12 watts (144 to 288 watt hours per day), a Suburban 6 gallon water heater with electronic ignition will draw about 1 watt at idle, an 12 watts while the burner is on. Modern LED RV interior lights will draw 3-9 watts when lit each (9 watt LED is about like a the amount of light from a 60 watt traditional bulb), so up to about 216 watts for a single light left on 24 hours, A fantastic fan roof fan draws 40 watts on high and 18 watts on low (multiply be number of hours used per day). A modern computer tablet (iPad, Android tablet, Kindle Fire, etc.) will typically have a 35-45 watt hour battery, so 40-50 watts consumed to fully recharge. A newer (less than 3-4 year old) 22 to 24 inch 12V RV TV will draw 25-45 watts while running, and 1-2 watts while "off"

 

[Mark_K5LXP]

All I will say here is camping with a single battery and a 180 watts of solar, that you had better be a minimalist as that is not a lot of power to run things.

I would guess a teardrop trailer has minimalist loads. One marine battery might be among the most marginal house batteries but in this case, "batteries included". I'd run the thing, maybe adding a basic battery monitor and see how it does in typical use. Even if it's woefully inadequate, it would be a data point to know what would be the follow on battery/solar solution for the OP's intended use. All my popup camper had was a U1 wheelchair battery and that ran the lights/fan/radio/device charging just fine.

Mark B.
Albuquerque, NM

 

[dpickard]

Thanks everyone! Excellent information!

 

[Merlin TC]

I don't know if this video will help you any, but I have my shop powered with solar. only thing i have not seen mentioned is, if you are running electronic, you want what is called a full sine wave inverter. most of the inverters like you get from harbor freight and other places are half wave inverters and can damage your electronics. as for the charging of the battery, when I was in Florida I had 2 sets of panels with seperate charge controllers, both feeding the batterys. the charge controllers can tell how much charge the batterys have and automaticly control the charge voltage. I plan to install this system in the shop into my R.V.that I am getting. it will be bit over kill, but would allow total off grid camping.