Is this Costco kit a good match for basic RV setup?

Hi,

I'm a newbie to solar and this forum, have scoured the threads here for the past few days trying to get "orientated" around the ins/outs of using solar for an RV application. I think I have my head around the basics, and have begun looking at costs/sources for the parts for my application. But first, here's my situation...

I have a 29ft travel trailer with 2 x 6-volt golf cart batteries, basically equivalent to Trojan T-105s (225 AH rated) connected in series for 12V output. I am looking at a possible solar setup for my travel trailer with the following goals:

1. Recharge/top-up my batteries between trips (over the course of 4 or 5 days) as I have to store my trailer at a lot without access to power. So return from a long-weekend, say, and park the trailer knowing the solar will recharge the batteries fully before the next weekend.

2. Extend my "range" in terms of available days of power while boondocking in the trailer. Typically use approx. 10% of capacity per day while camping. Most trips are 3-4 days long. Usually a single 2 week outing each summer as well, but can arrange for at least one "plug-in" stop in the middle to recharge batteries fully, so really on need 5-6 days of boondocking capacity.

3. Optimal cost/complexity/convenience for the above. :)


After poking around the web a bit at panels, controllers, etc., I came across this package at Costco (in Canada) that seemed to match my needs well with a reasonable cost, and the benefit of having a local Costco for any returns/warranty issues, etc.

Link

So my questions are:

1. Does this kit look like a decent fit for my needs? Will the output from these panels safely recharge my batteries between trips in a manner that is healthy for the batteries, etc.
2. Any serious concerns about the included products themselves in terms of quality, capability?
3. Is the price reasonable/good/bad?

Additional Notes:

- I would most likely mount the panels on the roof, either flat mounted or with the option of slanting them when parked if that seems necessary. From what I read here the slanting only provides 10-15% additional output, so it becomes a cost/convenience/benefit call. Not sure the additional effort is worth it. Seems like I could add the slanting capability later if I needed it.
- The charge controller isn't MPPT, but again, it's a cost/benefit call. If I need the additional AH output I can replace it with a better MPPT unit later, or tilt my panels, or both.

Am I completely off track here? All input is appreciated!

(Sorry if this is the wrong forum for this, maybe it's more about my setup/needs than the Costco offering...)

Regards,
Ken

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Is this Costco kit a good match for basic RV setup?

    Bloody expensive buying stuff in Canada, eh?

    At least they're Sharp panels. I don't see any details on the other pieces, but perhaps I'm not pushing the right button?

    In terms of function, you don't really need an MPPT charge controller anyway. Not in this application. But 175 Watts of panels is going to be a bit slim for keeping up 225 Amp/hrs of battery, especially in an RV application where you can't get ideal insolation most of the time. 240 Watts would be closer to your needs. How much panel can you fit on the roof? You can never have too much PV, except for having to pay for it! :p

    Is it a good deal? In general kits aren't. In general anything you buy in Canada isn't. You already know that!

    Try pricing out components on NAWS on-line store http://store.solar-electric.com/ and see what you get. Use that for a base-line - and add the usual highway-robbery-of-buying-it-in-Canada factor.

    Again, I don't see where it says the make/model of either the charge controller or inverter. Hard to tell. Can you see one in store? Chances are the inverter is not pure sine wave, so that has to be considered as to whether it will work in your application. 175 Watts isn't much, either.

    Maybe think long-term about this. Where would you want to be in terms of having non-generator power available? How many Watt/hours?

    Kamala would have good input on this question I'm sure!
  • KamalaKamala Solar Expert Posts: 452 ✭✭
    Re: Is this Costco kit a good match for basic RV setup?

    I also have an anti-kit bias. I would be very reluctant to buy a controller and inverter without knowing the manufacturer. (Bill has discovered that the controller is SunForce brand.)

    160W of panel would be enough to float the batteries for 4 or 5 days while in storage. Possibly for a 3 or 4 day trip during which 10% is drawn off the batteries each day. 250 to 300 watts of panels would be better. And remember, it rains sometimes.

    My case, I have 374AH of battery capacity charged by 261W of PV (45 degree tilt due south). My estimated daily usage is 87AH, or about 23%. If I estimate 80% efficiency and 5 hours of sunlight (wishful thinking perhaps) I just barely get to full recharge at a 4% rate. My system is designed right on the edge which is why I have the generator back up.

    The kit might be useful to you but I would not depend on it alone while boondocking.

    K
  • BB.BB. Super Moderators, Administrators Posts: 29,518 admin
    Re: Is this Costco kit a good match for basic RV setup?

    'Morning Ken,

    You have two questions--what amount of power does your RV need to properly recharge the battery bank and what about the Costco system.

    Lets assume you use the batteries to 20% state of charge (80% discharged--while this is a heavy discharge and not great for long life--you don't wan to go any deeper because you may permanently damage the battery bank). The amount of AH you have used is:
    • 225AH * 0.80 = 180 AH
    Lets assume that are somewhere in BC Canada, mount the panels flat, and are using this mostly during the summer months. Assume that you get >5 hours of "noon time" sun a day. Also that your battery bank is 80% efficient.

    The panels are 2x80 watts = 160 watts and Imp=9.34 amps.
    • 180 AH * 1/5 hours of sun per day * 1/9.43 amps * 1/0.80 = 4.77 days of sunny weather
    So, based on your requirements, this system would meet your needs...

    Now, batteries tend to sulfate when kept below ~75% state of charge--So, their life would be longer if you could get them >75% SOC quickly (within a day or so) and let the solar panels finish them off. Generator, using towing vehicle to charge, etc. would all help.

    Will your batteries last you 1-3 years or 3-5 years depending on how you take care of them (less deep discharging, getting them above 75% quickly, etc.)--maybe (I cannot foresee the future ;)). But, as long as you know the "costs"--Do what works best for you (not going camping and staying home for better battery life is not the end game here).

    Regarding the Costco system... The panels and charge controller PDF Manual) are probably fine and will do what you expect of them.

    Regarding the price--I would certainly shop around... I know that Canada is not cheap for solar products--and perhaps a trip to the US and some hand tools to install the system may be worth your time and trouble:

    First the solar panels... Generally, the panels over 100 watts tend to have a much better $$$/watt based pricing (if you can fit them on your RV). For example, you can get two Kyocea 135 watt panels for $720.

    The charge controller--there are two major types available. One is a PWM (as in the Costco kit), which work fine and are less costly.

    The other are MPPT (Maximum Power Point Tracking) which have several advantages. In cold weather, solar panels output higher voltage, and the MPPT controllers can convert that extra voltage into more current into the battery bank (maybe 10-15% on average, in subzero weather, maybe 20% or more). Also, you can wire the solar panels in series and run the panels farther away with smaller gauge copper wire (for example, you put the panels on a 25' cord and position them in better sun than where your RV is parked--remember panels need to be protected against wind gusts--or you end up with shattered glass).

    Lastly, see if you can get a Solar Charge Controller that includes a Remote Battery Temperature Sensor option. Will help ensure that the batteries are quickly and properly charged (pretty much mandatory for the Morning Star 15 amp MPPT charge controller). Batteries are very sensitive to temperature and properly charging voltages.

    A Morning Star PWM controller is around $80-$160... The smallest MPPT is $235 (plus more if you want the meter or PC Interface kit).

    Finally, the inverter... You can get inexpensive MSW (Modified Square Wave) inverters for almost nothing ($20-$30 or so). I would suggest a TSW (True Sine Wave) Inverter. If you are going to be charging your cell phones, running a laptop, TV, video player, etc.--Many of the small wall wart type transformers overheat when run on MSW Inverters.

    A really nice 12 volt 300 watt TSW inverter from Morning Star. Efficient, and goes into low power standby if loads are turned off... $260

    You did not ask--but some other nice to have options. If you will be using a fair amount of AC loads--get a Kill-a-Watt meter to measure them. It is also handy for use around the home to look for smaller energy hogs. If you will be doing a lot of DC loads--a DC Amp*Hour/Watt*Hour meter is nice.

    A good Hydrometer for the battery bank. And I like to recommend a Battery Monitor to keep track of your battery usage. Almost manditory for sealed batteries.

    Some FAQ's to read up on:

    Deep Cycle Battery FAQ
    www.batteryfaq.org
    All About Charge Controllers
    Read this page about power tracking controllers
    All About Inverters
    Choosing an inverter for water pumping

    Pretty much the whole point of having a good system with long life revolves around properly managing the battery bank.

    By the way, many of the above links are to our host's site as a starting point. However, you are more than welcome to look around for the best source for your location.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • KamalaKamala Solar Expert Posts: 452 ✭✭
    Re: Is this Costco kit a good match for basic RV setup?
    BB. wrote: »
    ... Lets assume you use the batteries to 20% state of charge (80% discharged--while this is a heavy discharge and not great for long life--you don't wan to go any deeper because you may permanently damage the battery bank). The amount of AH you have used is:
    • 225AH * 0.80 = 180 AH
    Lets assume that are somewhere in BC Canada, mount the panels flat, and are using this mostly during the summer months. Assume that you get >5 hours of "noon time" sun a day. Also that your battery bank is 80% efficient.

    The panels are 2x80 watts = 160 watts and Imp=9.34 amps.
    • 180 AH * 1/5 hours of sun per day * 1/9.43 amps * 1/0.80 = 4.77 days of sunny weather
    So, based on your requirements, this system would meet your needs...

    160W * 5hr = 800WH (640 if derated 20%)

    800WH / 12V = 67AH (or 640/12=53)

    Am I doing something wrong here Bill?

    OP says he uses 10% of battery per day, or ~ 26AH.
  • BB.BB. Super Moderators, Administrators Posts: 29,518 admin
    Re: Is this Costco kit a good match for basic RV setup?
    Kamala wrote: »
    160W * 5hr = 800WH (640 if derated 20%)

    800WH / 12V = 67AH (or 640/12=53)

    Am I doing something wrong here Bill?

    OP says he uses 10% of battery per day, or ~ 26AH.

    I used the Imp current because this is a PWM controller... Vmp (as long as it is >Vbatt charging) is not useful... The actual Power going into the battery (before deratings):
    • 9.34 amps * 14.4 volts (batt charging) = 134 watts
    • 5 hours * 9.34 amps = 46.7 amp*hours
    If this was a MPPT controller--then I would do the calculations in Watts.

    Yes, I assumed maximum battery discharge as a worst case condition, and I did not add any derating for the panels (although, temperature derating is irrelevant for current (in fact, current increases a little bit as the panels get hot). For his original loads, this system is sized fine. I used 5 hours as a minimum--should be a bit more for BC--depending on a whole bunch of weather factors).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Is this Costco kit a good match for basic RV setup?

    Wow! First, let me just say that you guys (and this forum) are awesome! :)

    So, keeping the 2 questions separate for now:

    1. Will this setup meet my power needs?
    Originally Posted by Kamala
    160W * 5hr = 800WH (640 if derated 20%)

    800WH / 12V = 67AH (or 640/12=53)

    Am I doing something wrong here Bill?

    OP says he uses 10% of battery per day, or ~ 26AH.

    So the answer seems to be Yes in terms of extending my boondocking days to 5 or 6, and Yes to recharging my batteries while in storage over the course of several days. I have never ran the batteries down below 60% or so (that's without any recharge capability) so I'm not too worried about needing to go lower than 50% generally. I do have a larger trailer this year, but we tend to keep things frugal in terms of power needs. We don't even have an inverter now, most of our stuff will charge/run on 12v DC. My wife does have a new netbook that would benefit from a small inverter though.

    There is also a concern that if the batteries are very low (below 50%?) when put in storage that it would be better to charge them to 80% via plug-in (or tow vehicle) quickly (the first day back) rather than let solar recharge more gradually over several days to avoid the risk of sulfication. Does that sound right?

    Another question, will the solar alone be enough to *properly* top up the batteries. Will they provide enough voltage etc.?


    Question 2: Is the Costco kit a good fit/deal?


    Okay, shopping around on the Wind&Sun storefront:

    Steca PR 1010 Solar Charge Controller, 10 Amp, 12/24 volt $126.00

    Kyocera KD135GX-LPU 135 Watt 12 Volt Solar Electric Panel $362.85

    Subtotal: $488.85
    Shipping: $82.32
    Total: $571.17
    + Import duties and brokerage = $35
    + GST = $30
    + Dollar exchange (10% to be safe) = $65
    = Approx. $700 Cdn for 1 135 watt panel and controller.

    So this would probably meet my needs and I should be able to add another 135W panel later if needed for say, $500 more.

    So the question becomes, is the low-end inverter, convenience of dealing with Costo, and extra 25watts worth the $300 (50% more)?... And the answer to that is - probably not! I also like the thought of one panel instead of two on the roof. :)

    I will also compare with what AEE Solar Canada has on offer since they have a warehouse right here in Calgary, might avoid shipping costs altogether.

    If I could ask one more question, does anyone have a link to a resource that would explain in detail the proper way to connect the PV controller to the battery, along with the existing AC/DC/charger converter in the trailer? From what I've read, seems like you basically hook the solar controller onto the battery in addition to whatever is already connected, but I'd like to see a more comprehensive overview/example. Is it okay to be charging the battery using the tow vehicle and solar at the same time, what about the solar and the plugin-converter/charger in the trailer?

    Thanks again guys, you are a great resource!

    Regards,
    Ken
  • BB.BB. Super Moderators, Administrators Posts: 29,518 admin
    Re: Is this Costco kit a good match for basic RV setup?
    kshopper wrote: »
    There is also a concern that if the batteries are very low (below 50%?) when put in storage that it would be better to charge them to 80% via plug-in (or tow vehicle) quickly (the first day back) rather than let solar recharge more gradually over several days to avoid the risk of sulfication. Does that sound right?
    The less time the batteries send below 75%, the less sulfation... In the end though, RV use is a tough service... Lots of temperature swings and sometimes deep discharge.

    Golf cart batteries properly maintained are probably good for 3 years or so... What you are doing to them is not going to take that much life away (unless you let them sit for days/weeks/months below 75% state of charge). Watch the water levels--running them dry (exposing the plates) is probably #2 on the battery hit list (right after #1 -- too much load, too little charging = deficit charging). (note--I am trying to be conservative here--if your system does better--be happy :D)
    Another question, will the solar alone be enough to *properly* top up the batteries. Will they provide enough voltage etc.?
    • Vmp>Vbatt-charging + 2 volts
    Flooded cell batteries, when equalized need 15+ volts, so, Vmp + 2 volts (controller and wiring drops) is generally fine for anything but very hot days and very cold batteries (Vmp>17 volts).

    If this system was in a hot desert--we would be looking at putting two panels in series and using an MPPT charge controller to allow you a wider operating range.

    Current wise, the normal recommendation for charging is ~5%-13% as a reasonable min/max charge rate based on 20 Hour capacity:
    • 225 AH * 0.05 = 11.25 amps
    • 11.25 amps * 17.5 volts (panel Vmp) = 197 watts minimum panel
    • 225 AH * 0.13 = 29.25 amps
    • 29.25 amps * 17.5 volts (panel Vmp) = 517 watts maximum panel
    The above numbers are just rough rules of thumb... So, you could easily add more solar panels and still be within a comfortable operating range for your battery bank.

    Economically, it may not be worth it. Using alternative power for charging will make up for the occasional deficit.
    Steca PR 1010 Solar Charge Controller, 10 Amp, 12/24 volt $126.00
    I don't know much about the Steca controller. Nice integrated unit... Looks like it may even include an internal load shunt for keeping track of AH into and out of the battery--very cool.

    One thing to watch those is that the maximum Load Current appears to only be 10 amps max (for the 10 amp charge controller). 10amps * 12 volts = 120 watts may not be enough power for your loads (laptop+inverter+various others)... May not handle inverter/AC load surges well.

    Also, a 10 amp controller may be too small if you want to add more panels later.
    If I could ask one more question, does anyone have a link to a resource that would explain in detail the proper way to connect the PV controller to the battery, along with the existing AC/DC/charger converter in the trailer? From what I've read, seems like you basically hook the solar controller onto the battery in addition to whatever is already connected, but I'd like to see a more comprehensive overview/example. Is it okay to be charging the battery using the tow vehicle and solar at the same time, what about the solar and the plugin-converter/charger in the trailer?

    For connecting the charge controllers, following the manual is always a good start (www.stecasolar.com).

    Here is a nice nice thread with video from Keven in Calgary Canada discussing many of the issues with installing panels on a small trailer. Even includes a video or two.

    Yes, you can charge the same battery bank with multiple charge controllers... Basically, the one with the highest voltage set-point "wins".

    Charging with a tow vehicle (DC cable from battery, through isolator, to trailer, to battery bank) usually does not do a good job of pumping amps into a battery bank. The resistance of the wiring, the voltage drop of an isolator, the 13.8-14.2 volts that most vehicle alternators are set at, etc., usually limit the useful charging current to less than 10 amps (just a guess).

    If you have a long drive, you could setup an inverter in the tow vehicle and run 120 VAC back to the trailer and run a 12 VDC battery charger into the bank--You will be able to charge the bank with a vehicle much better with that setup (obviously, the extra costs for a vehicle inverter, AC battery charger, etc.).

    In the case of longer stays and not enough sun, it is almost always better to bring a small genset (Honda eu1000i or eu2000i type) and a good AC charger than to attempt to charge with a tow vehicle (really fuel inefficient to charge with the tow vehicle).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Is this Costco kit a good match for basic RV setup?

    the question is if this would suffice for you and it may not. the 160w of solar may be about 9a at best when the pvs are aimed at the sun so we can assume with efficiencies and other loss factors it could be far lower than the 9a. even if the 9a where somehow there this represents 9a/225ah=.04 or 4% charge rate which is somewhat low and it would be less keep in mind. if you bulk charged with the alternator to 80% then this leaves 20% of the charge to go and it would take at least 5hrs of full sun with properly aimed pvs at that 4% rate minimally to bring it to a full charge. that is at least a day and most likely into the 2nd day of full sun that this optimistic charge from the pvs would take and you are certainly not going to want to wait until the batteries charge-up to use power. that 20% would also represent 2 days use without sun which is easily possible.
    i think you might be able to piece together something yourself much cheaper and there is more power in pvs to be had along with better controllers that could be had within that same price tag area. small modsine inverters are widely available and somewhat cheap so i believe you should shop around to put together the pieces at a better return for the investment. maybe check in an rv dealership to see their offerings too, but mostly to get a better idea on what you may want and how to go about it with price in mind. odds are the rv dealer will be even higher than costco.
    kicking thoughts around if it's at all possible, maybe plan your trip into the u s and then pickup the stuff even cheaper if you're traveling anyway. would the border guards know you didn't come into the u s with solar? i doubt they would as they don't inventory what you have when you leave canada.
  • System2System2 Posts: 6,290 admin
    Re: Is this Costco kit a good match for basic RV setup?
    the question is if this would suffice for you and it may not. the 160w of solar may be about 9a at best when the pvs are aimed at the sun so we can assume with efficiencies and other loss factors it could be far lower than the 9a. even if the 9a where somehow there this represents 9a/225ah=.04 or 4% charge rate which is somewhat low and it would be less keep in mind. if you bulk charged with the alternator to 80% then this leaves 20% of the charge to go and it would take at least 5hrs of full sun with properly aimed pvs at that 4% rate minimally to bring it to a full charge. that is at least a day and most likely into the 2nd day of full sun that this optimistic charge from the pvs would take and you are certainly not going to want to wait until the batteries charge-up to use power. that 20% would also represent 2 days use without sun which is easily possible.

    Well, my main goal is to have the batteries fully charge when there is no load on them when the trailer is in storage, between weekend trips. Since I can't store the trailer at my house (and plug it in), I wanted to be able to park it unplugged and still have the batteries topped up in time for the next weekend trip. The extension of potentially a few more days of boondocking is kind of a bonus. If it rains all week while the trailer is in storage I could bring it home to charge (plugged in), but I have to have my tow vehicle connected which would inconvenience the missus, as it's her daily driver.
    i think you might be able to piece together something yourself much cheaper and there is more power in pvs to be had along with better controllers that could be had within that same price tag area. small modsine inverters are widely available and somewhat cheap so i believe you should shop around to put together the pieces at a better return for the investment.

    Agreed. I am researching local alternatives now.
    maybe plan your trip into the u s and then pickup the stuff even cheaper if you're traveling anyway.

    Funny, I just drove through Flagstaff a month ago on my way back to Calgary. Oops. This might actually be an option if I decide to wait until mid-summer to add solar. Of course, then you have logistics and costs of having someone install the panels on my trailer in the middle of my family vacation, vs. me having time to do it now before the camping season begins.

    I guess it needs more thought.

    Regards,
    Ken
  • mike95490mike95490 Solar Expert Posts: 8,380 ✭✭✭✭✭
    Re: Is this Costco kit a good match for basic RV setup?

    If the weather forcast in your areas are any good, and you know you will be short on sun, you can use your tow vehicle's alternator to power a small inverter, to power a small charger, 6 hours of drive time, at 10 A, is not something to ignore. Tow vehicle alternator output is too low to properly charge a deep cycle battery, unless it's way down. (and the high load does not make the alternator very happy either.)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • RoloRolo Registered Users Posts: 11
    Re: Is this Costco kit a good match for basic RV setup?
    kicking thoughts around if it's at all possible, maybe plan your trip into the u s and then pickup the stuff even cheaper if you're traveling anyway. would the border guards know you didn't come into the u s with solar? i doubt they would as they don't inventory what you have when you leave canada.

    If buy something in the US be careful when sending in warranty cards or using your credit card for the purchase. If you have a US address or US credit card then use it. Otherwise pay cash. Some canadians have had their purchases tracked back to them through warranty cards and credit cards by cbsa resulting in payment of duties and penalties.

    One note about costco. they may either replace it or force you to deal with the manufacurer for warranty.
  • System2System2 Posts: 6,290 admin
    Re: Is this Costco kit a good match for basic RV setup?

    Hi,

    Okay, looks like local suppliers are indeed 20-40% more than US ones, unfortunately. With the Cdn dollar at par now I couldn't justify buying locally at this point.

    After more research, I've come up with an alternative potential setup (below), please let me know what you think:

    REC Solar 220 watt solar panel

    Specifications:

    Peak Power (Pmpp) 220 W
    Peak Power Voltage (Vmpp) 28.2 V
    Peak Power Current (Impp) 7.5 A
    Open Circuit Voltage (Voc) 36.1 V
    Short Circuit Current: 8.1 A
    Max. System Voltage: 600 Volts DC Max Series Fuse: 15A

    Morningstar Sunsaver MPPT 12/24V 15A Charge Controller

    The main benefits of this setup appear to be:
      Maximum charge performance per watt (24V + MPPT controller)
      Single panel
      Future expandability to 220W by adding another panel
      Cost effective(ish)

    Is the limited amperage output of using just one of these panels (7.5A) a fatal limitation with this setup? Any other comments/concerns?

    Regards,
    Ken
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Is this Costco kit a good match for basic RV setup?

    It may still be too little power to charge a 225 Amp/hr 12 Volt battery bank.
    Basic calculation:
    220 Watts @ 80% efficiency = 176 Watts @ 14.2 Volts charging = approx 12 Amps, which is just above the minimum 5% recommended for a 225 Amp/hr battery.

    Keep in mind that a charge controller's Amperage rating is its output limitation. That Morningstar can put out 15 A @ '12 V' (about a 210 usable Watt array) or 15 A @ '24 V' (about a 420 usable Watt array). Having more array on the input than it can handle will just be a waste of panel $; the output is limited to 15 Amps.

    For RV use, you'd probably want to stay with a 12 Volt system but up the capacity for both array and battery in future. Maybe consider this CC instead:
    http://store.solar-electric.com/ps-30.html
    And two of these panels perhaps?
    http://store.solar-electric.com/kykc130wasop.html

    That would give you 270 Watts @ 80% = 216 Watts usable @ 14.2 Volts charging = approx 15 Amps, which is about 7% of the Amp/hr capacity. It could surprise you pleasantly on a sunny day!

    You don't really need the MPPT function if you don't need to 'downconvert' array Voltage, so why pay for it? On a small system (one or two panels, etc.) the PWM set-up is fine.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Is this Costco kit a good match for basic RV setup?

    in any case the sunsaver mppt is limited to the 15a output no matter if you have 12v or 24v pvs feeding it or even if you are going with a 24v battery bank. either get 2 of these controllers or one much larger (preferred).
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