TT not Solar Ready But I Am - Questions

[stateboy]

So, we decided to go off the grid (away from electricity) when we camp this summer on one of our several planned trips within Michigan. I have a 2016 non-solar ready TT (no pre-wiring). I understand the basics of what I can and can't run off the battery (12v verses 120v appliances and outlets). I don't have an inverter (I do have a portable one I can plug into the 12v port in the TT though) and I'm not looking to get one. I'm thinking a 100 watt panel to start with along with the controller. I'm looking at portable and not mounting it to the TT for now. I want to run what I need at night and recoup energy during the day. So, I'm considering three different kits but would consider other choices since I'm not well versed in this area.

- Portable (maybe mounted later)
- 100 watt panel (to start with)
- No inverter
- Currently have 12v Interstate RV battery, 505 cranking amps, 100 reserve amps

Costco has the Coleman kit for $120 (normally $160) was one choice. The other two are Windy Nation and Renorgy. Prices may vary on the other two choices (higher from what I've seen). My questions are...

Any pros or cons from those three?
Other choices to consider?
Is 100 watts enough?

It will be just a three day run in August but it will probably open the door to more. Thanks all!

[tbwill]

I would suggest that before purchasing any solar system you first upgrade your battery and purchase a shunt based battery monitor. Your current battery is a dual-purpose battery with 64 amp-hours of capacity. Since the general rule of thumb is to only discharge to 50%, that means you only have 32 amp-hours for nightly use. Replacing your battery with 2 - 6 volt golf cart type batteries wired in series will give you a capacity of 200 to 240 amp-hours X 50% = 100 to 120 amp-hours capacity. There are also battery decisions to make…stay with lead acid, AGM, Lithium in price increasing order. The battery monitor is a must and will be needed with your system anyway. I have one from Bogart Engineering the same brand of controller I have, Victron makes a nice one, I believe Renogy has one. Make sure it a shunt based meter. I consider this to be the most important part of my solar setup. Install a battery monitor and go camping and see what you actually use. We installed two 180w panels, two 235 amp-hour Crown 6 volt batteries and have a small 300 watt inverter that is plenty for watching TV, charging the laptop, charging iPads and phones. I just recently installed a 2000 watt inverter to allow me to use a coffee pot, toaster, hair dryer, microwave, etc. I am also adding another 180w panel to get as much power back into the batteries as early as I can during the day, because the final step of charging slows down considerably as the batteries reach full condition. I did not go the kit route, I put together my own system so that the wiring would be sufficient for the additions I am doing. Voltage drop is the biggest concern and the 10 awg wires supplied with most kits are not sufficient to keep the voltage drop under the recommended 2%. I went with 6 awg welding cable from the roof to the controller and kept the controller as close as I could to the batteries. There is a lot of information in the RVing With Solar Community Group https://www.jaycoowners.com/forums/g...ith+solar.html

[stateboy]

Originally Posted by tbwill

I would suggest that before purchasing any solar system you first upgrade your battery and purchase a shunt based battery monitor. Your current battery is a dual-purpose battery with 64 amp-hours of capacity. Since the general rule of thumb is to only discharge to 50%, that means you only have 32 amp-hours for nightly use. Replacing your battery with 2 - 6 volt golf cart type batteries wired in series will give you a capacity of 200 to 240 amp-hours X 50% = 100 to 120 amp-hours capacity. There are also battery decisions to make…stay with lead acid, AGM, Lithium in price increasing order. The battery monitor is a must and will be needed with your system anyway. I have one from Bogart Engineering the same brand of controller I have, Victron makes a nice one, I believe Renogy has one. Make sure it a shunt based meter. I consider this to be the most important part of my solar setup. Install a battery monitor and go camping and see what you actually use. We installed two 180w panels, two 235 amp-hour Crown 6 volt batteries and have a small 300 watt inverter that is plenty for watching TV, charging the laptop, charging iPads and phones. I just recently installed a 2000 watt inverter to allow me to use a coffee pot, toaster, hair dryer, microwave, etc. I am also adding another 180w panel to get as much power back into the batteries as early as I can during the day, because the final step of charging slows down considerably as the batteries reach full condition. I did not go the kit route, I put together my own system so that the wiring would be sufficient for the additions I am doing. Voltage drop is the biggest concern and the 10 awg wires supplied with most kits are not sufficient to keep the voltage drop under the recommended 2%. I went with 6 awg welding cable from the roof to the controller and kept the controller as close as I could to the batteries. There is a lot of information in the RVing With Solar Community Group https://www.jaycoowners.com/forums/g...ith+solar.html

Thanks for the input tbwill. I knew the battery was a low grade RV type to begin with. How did you determine the amp hour value? From the numbers I provided? This trip isn't until August so I have time to look at what you spoke of here. Thanks, too, for the heads up on the social group RVing with SOLAR. I joined that so hopefully I can glean more info from there.

I use app Tapatalk 99% of the time so I don't see those extras the JOF offers on the desktop version. Now, I'm off to read more...

[tbwill]

Originally Posted by stateboy

Thanks for the input tbwill. I knew the battery was a low grade RV type to begin with. How did you determine the amp hour value? From the numbers I provided?

I looked up the battery on the Interstate website. Anytime a cranking amps is advertised or listed on a battery you can pretty much guess that it is a dual purpose battery rather than a true deep cycle battery.

[stateboy]

Originally Posted by tbwill

I looked up the battery on the Interstate website. Anytime a cranking amps is advertised or listed on a battery you can pretty much guess that it is a dual purpose battery rather than a true deep cycle battery.

I thought the cranking amps on a RV battery was a measurement of comparison for something like a trolling motor. I think of it similarly to cold cranking amps on car batteries. Thanks for your efforts. It's replacement will probably be two 6v when the time grows close.

[tbwill]

Here’s a link to the install I did on our 27RLS https://www.jaycoowners.com/forums/f...ect-60634.html

[ttavasc]

Originally Posted by stateboy

Thanks for the input tbwill. I knew the battery was a low grade RV type to begin with. How did you determine the amp hour value? From the numbers I provided? This trip isn't until August so I have time to look at what you spoke of here. Thanks, too, for the heads up on the social group RVing with SOLAR. I joined that so hopefully I can glean more info from there.

I use app Tapatalk 99% of the time so I don't see those extras the JOF offers on the desktop version. Now, I'm off to read more...

It sounds like you have an Interstate HD24-DP Group 24 flooded lead acid battery. That is the same battery our ORV came with. If you go to the Interstate web site and search for that model you can find the Amp Hour rating on the Specifications tab - you may have to scroll down the page to see that tab:

Interstate HD24-DP

The Amp Hours listed are 64. If you have just one of these batteries and only allow discharge to the recommended 50% of capacity that is a mere 32 amp hours. It doesn't last long.

tbwill's post has some very good details. Having a good quality shunt-based battery monitor is a must. I have the Victron BMV-712 and love the Bluetooth capability. The Crown 6-volt batteries that tbwill has are high quality. If I could have found them locally here that's what I would have gone with. I ended up with a pair of Trojan T-125 240ah 6-volt. Unfortunately, due to the current pandemic our maiden voyage with the new electrical upgrades has been delayed a bit.

[stateboy]

Thanks ttavasc for your reply. We have several trips planned. However, we'll have to see where this virus pandemic takes all of those reservations. The boondocking reservation isn't until mid-August so as I consider solar, I can also reap the benefits of what others have learned as well as what I might want to buy just once rather than two or three times to get it right. I joined the RVing With Solar discussion and am educating myself on what I need verses what I want.

I verified the battery and it is the one that only offers 32 amp hours when run to 50% capacity. I enjoy the learning curve. I just don't want it to be an expensive one.

[stateboy]

Originally Posted by tbwill

Here’s a link to the install I did on our 27RLS https://www.jaycoowners.com/forums/f...ect-60634.html

That's top end for me. Great job!

[EvilDoer]

Before you go buying solar panels, or upgrading batteries, or otherwise spending a bunch of money; it would be a good idea to determine what you need.

Spend $30 on Amazon on a simple meter like the DROK DC 0-300v 200amp STN LCD (you can upgrade to a shunt later if you wish). Then spend a night dry camping, either in your driveway, or in a campground with your rig unplugged. If you have enough amperage to get through the night great, if not then look at upgrading your battery. No point in buying a couple hundred amp hours of batteries if you're only using 25. Don't worry about completely draining your current battery during this test, if that happens you'll want to replace it anyway. Also, you f you need a couple hundred amp hours of battery you'll be needing a whole lot more solar panels. If you're not using your inverter, and you're only running led lights, the water pump, maybe a 12v fan, and definitely NOT the furnace, your current battery may be adequate.

If your current battery isn't completely dead in the morning, you may still want (but not absolutely need) a true deep cycle battery if you're going to be doing more of this type of camping.

Besides the panel sets you listed, maybe take a look at a kit from Northern tool.com Item# 88432.

Lastly, if you find you like this disconnected sort of camping, look at kits that are expandable. Can you add additional panels? Can you upgrade the charge controller? Will the current controller handle more/bigger batteries if you add enough panels to charge them in one day?

[travelingjw]

Some great information from the others. I would suggest starting with a minimum of 200 watts. I have Renogy. I started with one 100w panel and found it OK on days with full sun. But unless you can move it every hour or so trees, clouds, etc. will block the sun. After adding the second panel I had no problem. Mine are both portable so if I am around the campsite I will move them (if needed) every two to three hours. With the 200 watts I have found that it keeps my battery charged and have no trouble using everything but the microwave/air-conditioner (which both need 120 volts).

[Greg58]

I’m new to solar so I’m seeking advice, I will be running led lights and water pump plus refrigerator display on 4 day hunting trips this fall, will a 30 watt panel with controller help keep the battery charged? I’ve found a lot of info here on the forum but I’m seek first hand experience.

[travelingjw]

Others may give your the exact technical specs but my experience says you are way under powered. Every year we do a 4 day boondocking trip. We run the refrigerator, lights, water pump and found that a 100w panel was not enough unless we had full sun for 6 - 8 hours. We now have 2 100w panels and do fine.

[Greg58]

Thanks, the fridge will be on gas with only the display on 12volt. The water heater will be on gas as well. Basically the pump and lights and charging phone or gps is what I’m after.

[Akraft]

The RV average battery is rated at 75 amp-hrs. You can only use half before re-charging without damaging your battery. That leaves 37.5 amp-hrs usage. The formula for battery usage is (Device current (amps) * Time used (hours) = Amp-Hrs).

Below is the current measurement from my trailer:

Measured Amps
CO2 Detector (Det) 0.1
Radio 1.2
Bedroom DC TV 2.5
Living Room TV w/invertr 4.5
Lights <0.8
Refrigerator 0.8
Water Pump (while water is running) 5.0
Hot Water Heater 0.4
Furnace 8.6

Solar Panels:
To recharge you can mount (or use portable) solar Panels. In good light you get approximately 25 amp-hrs of charge with with every 100 watts.

Battery Upgrades:
My Travel Trailer has room for 2 batteries on the tongue. I put use two 6 volt Golf Cart batteries in series that are rated for 215 amp-hrs. That means I can use 107.5 amp-hrs before discharge.

Calculate out your needed daily usage (Amps * Hours = Amp-hrs) based on the table above how much you need. Mount the appropriate solar panels on the roof or use portable to match the maximum amp-hrs you think you will need per day.

Note: You can use an inverter for AC power needed except for the Air Conditioner or the microwave. Those two items draw so much current that the batteries and solar panels needed are not feasible for an RV. Also remember, if you use a inverter the battery draw will be ten times the 120volts ac current draw. Inverters tend to draw the battery down quickly if you get carried away with the 120 volts ac usage.

I hope this helps.

[Akraft]

100 watt solar panel is perfect for that battery. On a sunny day, position correctly you should get 34 amp-hours per day. On a Hazy day about 20 amp-hours. Your Battery has 32 amp-hrs of daily usable storage capacity. You might consider 120 watt portable that will boost that to 41 amp-hrs on a sunny day and 25 amp-hrs on a hazy day.

If you plan on dry camping I would upgrade your battery size. I bought two 215 amp-hr 6 volt batteries for $105 each at Batteries Plus. That ups you usable storage to 107.5 amp-hrs. Then you would want to increase it to 300 watt solar panels that would provide 102.5 amp-hrs on a sunny day and about 61 amp-hrs on a hazy day.

It all depends on your needed daily usage.

[stateboy]

It's been a little over a month since I started this thread. I appreciate all the great information from the posts here. I went over to the RVing with Solar thread and read every single post, starting from the oldest to the newest. Yes, my head is bulging a bit with all the information. My next approach is to go to the tech talk thread and search for the solar threads there.

Michigan State Parks extended their shut down till the latter half of June, wiping out our Memorial plans (trip #2 gone this year) and our governor extended our stay-at-home today to May 28th. I guess it gives me more time to finalize my approach to solar power.

(Warning: run on sentence here) Seeing how others put their projects together, using the energy estimates provided for various appliances, looking at different brands of solar power that people migrate toward, sorting through the various controllers, considering how many watts I will be content with, buying a battery monitor and camping in the driveway to check my needs and then deciding whether portable is the best idea (for theft reasons) are some of the answers I think that have begun to solidify in my mind.

I'll probably upgrade the trailer in 3-5 years so I'm not going to go overboard (premium equipment/high dollar). Right now, I'm leaning towards 300-400 watts of panels, a MPPT controller and a battery monitor this year to get the feel of solar. I'll upgrade the battery situation next year when we plan on going west (from Michigan) to South Dakota, Wyoming and Montana federal parks. I'll consider the shutoff switches as well. This will allow additional study time and hands on use to see what the big boys in solar are doing here.

Thanks again for all the help.

[Greg58]

I've been doing the same, I'm going to start with 100 watts and add if needed. My little 165 doesn't have a lot of room for panels. All I'll run are LED lights and the water pump sparingly, hopefully with two batteries we'll make do.

[Greg58]

I camped last Wednesday through Saturday on a hunting trip with no issues, we were able to shower and use lights as needed. The 100 watt panel seems to be just enough, I may add another panel just to make sure.