Solar Setup: 2nd battery/ roof mounted panel vs a "power station"/ briefcase

NotYourGuy

Thoughts and opinions greatly appreciated regarding the pros and cons of going with a roof mounted panel setup and 2nd battery vs buying a couple briefcase panels and a GoalZero 1500w power station (or something similar). My thoughts are that the portable setup will probably be more expensive, but perhaps more useful as I can use it when not camping/ power outage in the house/ tent camping. Roof mount seems complicated (I know NOTHING about setup / install), but would always be there, out of the way, and more streamlined process/ plugs in the trailer work vs needing to plug into the power station. Thank you so much for your thoughts, this is a big purchase for me, so your insight is super valuable to me.  

VictoriaP

I went portable, but that was because at the time, permanent installation was beyond my budget (physical limitations mean I cannot do my own installs for most things). Permanent has advantages: continues to charge while driving, set and forget, no need to worry about theft so it works from sunrise to sunset. It also has its disadvantages: trees, clouds, limited amount of roof space available, not always facing the right direction or at the right angle to maximize the collection of energy. 

As far as a GZ Yeti, while I do have one and the plug to connect my solar panels to it, it’s more of a backup. Why not simply set up a quick disconnect on your trailer battery if you don’t already have a solar port? You’ll need a controller for the panel, but once that’s put together, it really is as simple as quick connecting the panel to the battery and setting the panel out in the sun. The Yeti doesn’t have to be part of the equation at all unless you need it for other purposes (which is why I have mine).

pthomas745

You don't know how much you need until you know how much you will use.  What camper do you have?  Which fridge?  What will you use the (spendy) Goal Zero for?  My 100 watt panel and basic cable (SAE port, battery clamps, etc) can charge every battery in the campground...(almost).

Reading various solar posts here...it seems to me that people are buying installed solar AND then buying separate panels.  The other issue to think about on installed panels is: failure.  What happens when/if they fail and need to be replaced?

Victoria pointed out the advantages of the installed solar, and all of that is relevant. 

DougH

A couple more disadvantages to permanent if thinking of the flex panel route: hail, and summer sun (whose heat is conducted into the cabin).  Every year flex panels get better and more bulletproof, but they're not invincible yet.

For the permanent option, I use VHB tape to adhere them to a clean roof, then run the lines to a hole in the passenger rear underside to where two of the batteries, controller and inverter live. Ugly cable routing. Others run the lines forward and put the controller in the tub and have two batteries in the front.  Some are now experimenting with running the lines down a vent for a cleaner look. Any of those roof mount choices you could do in a couple hours.

NotYourGuy

Thanks for the comments so far. My thoughts on getting the portable route are mainly that I would be able to use it for other purposes as well. My main reason for buying the T@b (2014) is that I am working from home now, and tired of sitting in my kitchen, so this is my new portable office so I can go work at the beach, in the mountains, etc. So charging devices is actually my main concern (followed by fridge/lighting). I think the idea of doing the solar on the roof AND having a briefcase panel probably makes good sense. I'll read the forums to try to figure out which are the better components to buy to make it happen.   

VictoriaP

Using solar to power things requires matching your consumption to your supply. Get it right, and you can run on solar virtually forever. Get it wrong, and you’ll need a backup power source. Case in point, I run three battery powered outdoor cameras with solar panels all year long. Two of them are identical cameras, same battery capacity, but the newer one has a panel twice the size of the older one...which also is in a poorer location for catching enough sun. Guess which one charges fine on it’s own all summer, but by October needs periodic manual charging? That same smaller size panel charges a less hungry camera just fine all year long though.

So, start by actually calculating your needs. There’s a spreadsheet around here somewhere by @jkjenn, who measured the amp hours used by each component of her 2015 Tab, and that’s a good starting point. But then on top of that, in your case, you’ll need to figure out how much power your computer consumes, and any cell booster that may be required to get the signal you need in remote locations, plus anything else equipment-wise that you’ll be bringing along.

From there, you’ll be better equipped to calculate the amount of battery capacity you need, and the number of solar panels it will take to supply that power.

Bclarke

I have a similar question... we have a new 320 S Boondock - built in solar.  We will only be out for a few days at time but mostly in the trees so solar isn’t going to be reliable.  A generator or inverter are the obvious options but go against my outdoor ethos (noise/fuel).   So I have been wondering if a portable power station like one from Jackery is an option.  Is there a way to have this charge the battery?  I know I can upgrade the TaB battery but this portable option seems far more useful.  By recharging the battery i can use the already built in systems vs running cords to the power station.   Hmmmm... so many thoughts... 

Sharon_is_SAM

Depending on how long you plan to stay out and what you want to run, you may find that your power needs outstrip the Jackery.  Besides, unless hooked up directly to the Jackery, you would need to plug in a battery charger and then charge your TaB battery.  It would require larger wires to prevent overheating and you would still only get limited supply.  

I think expanding your battery capacity is the answer if you are only looking at a few days at a time.

pthomas745

@Bclarke have you been out in your camper yet?  The "portable batteries" like the Jackery, are just lithium batteries in a pretty case.  If you just want to be able to run/charge your extra things (camera batteries, phones, etc) an extra battery like that is perfectly useful.  (See Sharon-Is-Sam for the opinions above on whether it would recharge your battery). 

I carry an extra battery for all those "extra things", (which I can recharge with my portable solar panel very easily).  I think you should try camping in your "shady"s spots a few times and learn for yourself how well your solar setup and what your personal power usage is.

Bclarke

@pthomas745 but isn’t half the fun just buying new stuff?  😁   I will learn soon how much draw etc we will have but admittedly I haven’t.  I am not concerned about phones and things as there a gazilion little chargers that will add a day or two .. but really more about the fan, cabin lights, and fridge (which is 100% battery).  

Denny16

Having a 100 watt port solar panel that you can put in the sun, will help to keep the battery charged, is a good idea.  Just be sure it has its own controller and hook it up directly to the battery.  Thst way both the roof and port panel will work,to,charge the battery.
cheers

pthomas745

@Bclarke the fridge will be your biggest concern.  The fan?  Even on my 40 amp hour stock battery I can run it for.....about 20 hours straight.  The lights in the trailer?  I can turn them all on.....and the battery could make them go for about 40 hours straight.  I carry that ordinary small battery that gives me a decent amount of power to charge my laptop..I take a lot of pictures.  Those "little things" in the trailer are quite efficient.

Figure out exactly what fridge you will have.  (They are soooo much more efficient than the fridges from just a couple of years ago.)  Find out exactly what battery will be installed.  (A stock battery would be about 80 amp hours...of which 40 would be "usable" to maximize battery life.)

Go read Jenn Grover's blog about battery management.  There is a spreadsheet there that covers what uses what in the trailer. (Be careful with the fridge numbers......)

https://jenngrover.com/guilty-as-charged-rv-battery-use-management/

This is the "old" spreadsheet...use this as a guide, and not the final word on power usage.  It works well for my 2017...and the newer trailers are even more efficient. (Again:  the fridges listed do not reflect your much more efficient fridge.)

VictoriaP

@Bclarke To answer your original question, I carry a Goal Zero Yeti 400 lithium...roughly equivalent to a mid range Jackery. And yes, I’ve used it to top off my group 27 AGM on the Tab, via a NOCO Genius charger attached between the Yeti & the AGM. It can be done, but to me, it’s an emergency fix and not a good or efficient solution to an inadequate battery setup. Much better to invest in a good battery (a big 12v AGM, or two 6v golf cart batteries, or a lithium) and possibly additional solar if needed. The GZ Yeti has a lot of other uses, which is why I have it, but as a backup to the Tab battery, it really is just a backup. 

In your shoes, I would look through threads on the 2021 320 and battery usage, there are at least a couple around here. While the 12v fridge is reasonably efficient, reports last summer seemed to indicate a much shorter than expected amount of boondocking time with the stock solar and a hefty pair of 6v GC batteries. I don’t know if that’s the most recent data on the subject, but I know at the time, it was concerning enough that we had several members decide to add additional solar panels either on the trailer or as add-on portables.

Marceline

Bclarke said:

I have a similar question... we have a new 320 S Boondock - built in solar.  We will only be out for a few days at time but mostly in the trees so solar isn’t going to be reliable.  A generator or inverter are the obvious options but go against my outdoor ethos (noise/fuel).   So I have been wondering if a portable power station like one from Jackery is an option.  Is there a way to have this charge the battery?  I know I can upgrade the TaB battery but this portable option seems far more useful.  By recharging the battery i can use the already built in systems vs running cords to the power station.   Hmmmm... so many thoughts... 

I wouldn't go the portable power station route unless you have some other use for it besides running things in the T@B (like backup power at home in case of a power outage). The biggest Jackery (Explorer 1000 Portable Power Station) is about $1000 and only has a 46.4Ah lithium battery. For that $1000 you can buy a 100aH Lithium battery that will solve all your problems.

Bclarke

@pthomas745 attached is the fridge information.  In reading replies to my question it does make sense to possibly pursue an upgraded battery.  Thanks too @Marceline for your comments.