New to Solar Power

Zakarume
Zakarume Solar Expert Posts: 143 ✭✭
Hello everyone. New to forum and solar power. I just bought a Coleman Fleetwood Pop Up Camper and a Harbor Freight 45 Solar Power System. What i am trying to find out is this. At night if weather is cool i just want to use battery power with 2 fans running. Is 1 12v battery good to run all night or do i need 2? Or is it better to get 6v batteries?
1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter

Comments

  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New to Solar Power

    It is all about the numbers, the batteries hold X amount of power to 50% SOC (the maximum recommended discharge level). You need to know about the amount of power required to run the fans. That will tell you the needed battery size. Then the next part of the equation is to put the power back in the battery, this is the sizing of the solar components to replace the previous nights consumption.

    Start with loads as always.
  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    Re: New to Solar Power

    I will be roughly using about 100 watts of power at night, maybe as high as 150 watts
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: New to Solar Power

    Welcome to the forum.

    Well it's not quite as simple as that. Batteries come not only in different Voltages but also in different capacities, rated in Amp hours. So in theory you could have a 12 Volt battery with the same capacity as two 6 Volts in series. Voltage times Amp hours is Watt hours; the quantitative measurement of electric power.

    There is also the Depth Of Discharge factor: how much of that power you can use before recharging becomes difficult or even impossible. As a rule you don't want to take a deep cycle battery below 50%, at least not on a regular basis.

    That is another thing: not all batteries are deep cycle and meant to be used in this manner. Those that aren't soon die if they are. :D

    Plus (is this getting tedious yet?) you have the main issue of how much power are your two fans using. This is key to getting the battery size right, and that is key to getting the solar right. Don't expect much from your HF 45 Watt panels; they have a reputation of being over-rated.

    For the most part two 6 Volt batteries that are each the same size as the one 12 Volt battery will give you more stored power. Your 45 Watt panels will at best supply about 2.5 Amps of current, which is really quite low for any typical battery (much less two GC2's for example). It would be in the recommended range for 25 Amp hours @ 12 Volts, and that's not a lot of battery: 144 Watt hours @ 50% DOD.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: New to Solar Power
    Zakarume wrote: »
    I will be roughly using about 100 watts of power at night, maybe as high as 150 watts


    For how long? That makes a difference. 100 Watts for 1 hour is 100 Watt hours. For 30 minutes it's 50 Watt hours. For 8 hours it's 800 Watt hours. Compare that to the info on battery size that the HF 45 could possibly support.
  • AuricTech
    AuricTech Solar Expert Posts: 140 ✭✭
    Re: New to Solar Power

    Building off Cariboocoot's comment about getting the battery size right, your Harbor Freight solar panel kit can reasonably support a 12V battery bank of about 50 Amp-hours capacity. For your application (occasional use in a tent-trailer), an Absorbed Glass Mat (AGM) battery like this Universal Battery 50 Amp-hour AGM battery would be a reasonable choice. I suggest an AGM battery because they don't require adding water and they have a self-discharge rate that is lower than that of flooded lead-acid (FLA) batteries.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New to Solar Power

    The Harbor freight panels also tend not to be very efficient--They are about 2x the area of a good crystalline solar panel and not very reliable.

    They are certainly OK to play with and do some experimenting--But if you are going to permanently install the power system and bolt on solar panels--You should go with the standard glass panels with mono or poly crystalline cells.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: New to Solar Power

    Solar usually doesn't work out too well for once in a while use. If these were recently purchased you might return the panels and check and see if they have a 12v 35 Amp hour AGM battery (about $70). That and a charger, likely buy that somewhere else, need one for AGM batteries, and you'll be better off, AGM can normally be discharged to a greater depth.

    I use O2Cool 10" fans, they really put out a good bit of air for a small 10" fan, I have 2 running now! They use a 700 ma at 12 volts, you can likely run 2 fans 2 nights (8 hours) on the battery. They are available at Walmart in the sporting goods area for around $20(without adapter), or at Amazon with and A/C adapter for $20

    You might get everything for what the 45watt solar kit costs!
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: New to Solar Power

    You might be careful if your using the solar panel kit with AGM batteries, be sure the charge controller is designed to charge AGM batteries, if over charged the battery dies, and they have different charging parameters than standard flooded batteries.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: New to Solar Power
    Zakarume wrote: »
    ... Harbor Freight 45 Solar Power System. .....
    return that before you get mad enough to smash it. It's not worth it's weight in recyclables.

    Sorry, it will only disappoint you in the long term. You will find you need to buy quality panels, a real charge controller and a pure sine inverter to not fry your electronic gear.
    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 ,

  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    Re: New to Solar Power

    ok. In theory this is what i want to use. 2005 Coleman Fleetwood Pop up. 2x 12v http://www.oreillyauto.com/site/c/detail/SSB2/31DCM/N0369.oap?ck=Search_N0369_-1_-1&pt=N0369&ppt=C0327. Solar Panel Kit to charge Batteries. http://www.harborfreight.com/45-watt-solar-panel-kit-68751-8527.html. And a http://www.sears.com/diehard-425-watt-power-inverter/p-02871496000P. The Fans i will use at night will be 2x http://www.walmart.com/ip/Honeywell-Turbo-Force-Air-Circulator-Fan-HT-900-WMT/16503230. Total watts used during night might be close to 100. Dont have lots of money to spend. Will this work through the night on the batteries?
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    Re: New to Solar Power

    Money is limited and will probably use it a couple times a year
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
    Re: New to Solar Power
    AuricTech wrote: »
    Building off Cariboocoot's comment about getting the battery size right, your Harbor Freight solar panel kit can reasonably support a 12V battery bank of about 50 Amp-hours capacity.

    Actually all of this hinges on the question posed in message #5, otherwise we are winging it.

    In addition, we don't know where the op's geographical location is so we can't determine the solar-insolation hours either. Zakume, where are you located, and how many hours per night are you going to run that equipment? Are those fans ac or dc? Are the ratings you listed from your own cumulative hour calculations, or just off the back of the device?

    The HF panels would not be my first choice either, but they do put out the rated power, albeit being slightly physically larger than mono/polyscrystalline since they are thin-film. Yes, they are plasticy and tend to warp over time, along with possible polarity reversals in the wiring, so one should always check that with a multimeter.

    The biggest upgrade would be to use a quality charge controller like a small Morningstar or Xantrex pwm, rather than rely on the one supplied with the kit - although I wouldn't spend too much on these kits as they tend to be an exploratory setup which usually gets a total redesign and a purchase of entirely new hardware. :)

    Most of the inexpensive charge controllers that don't specifically have an "agm" setting, can use the flooded setting, which is typically 14.4-14.8 volts. Of course they can't handle any EQ that would be used for FLA, so if that option is available turn it off. Sadly, many of the controllers are put to use with agm's with the "sealed" setting, which is really intended for GEL, and the voltage is too low for agm - like 14.1v max. Your agm's will now be regularly undercharged and die early. As always, check the manual for the specific voltages, and not just rely on the silkscreen label.

    Until we know the answer to post #5, there is no way we can recommend any particular size of battery storage.

    One thing we can do if the op wants to use an AGM comes directly from the last page of the PowerSonic agm manual. While not as accurate as the more precise calcualtions presented in other threads, you can do a back of napkin calc to see if you are even in the ballpark:

    Ah removed / Ah of charger * 1.78 compensation (accounts for finishing the absorb cycle).

    In the case of the 50ah agm, and you removed 25ah nightly, and only had the 45 watt HF panel kit (2.5a max under best conditions) means

    25ah needed to restore / 2.5a from panel * 1.78 = 17.8 hours needed to finish absorb.

    Problem is, we don't know the solar insolation hours. Let's be generous and assume 4 hours daily:

    17.8 hours / 4 = 4.45 days. And that is with no load.

    We really need to know the answer to post #5, and the geographical location of the op. :)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New to Solar Power

    Need to be very clear here... It sounds like you may have a 100 Watt load for 8+ hours per night:

    100 Watt * 8 hours = 800 Watt*Hours

    The fans appear to be 120 VAC, so you also have the losses of the AC inverter (somewhere around 85% efficient).

    800 Watt*Hours * 1/0.85 inverter eff * 1/0.52 solar system efficiency * 1/5 hours of full summer sun per day = 362 Watt solar array to "break even" in summer

    Your 45 Watt panel will do next to nothing recharging your battery bank.

    And, say you have 2x 6 volt 220 AH "golf cart" batteries... Pretty good size for a small RV. Your Diehard batteries are automotive/marine type batteries and will, if you are lucky, last 5-10 80% deep discharge cycles before they die (a real guess on my part).

    And you want to run two nights without the solar array/other charging sources. The best you could expect to supply per night would be (assuming you use 80% of battery capacity over those two days--That means you may have to replace the battery bank every 1-2 years from deep cycling):

    12 volts * 220 AH * 0.85 AC inverter eff * 0.80 discharge of battery * 1/2 days of stored power = 898 Watt*Hours per night

    The above battery bank will just keep up with my guesstimate of your nightly power loads (for 2 days of dry camping and little to no solar power charging).

    Is this helping? Unfortunately, we have to revert to the "math" pretty early when working with new designs. Guessing/miss-understanding your power usage (on my part) will not help you towards a successful design/installation.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    Re: New to Solar Power

    Live in Missouri. Southwest Area. Up to 10 hours at night will be using the batteries. Fans are AC if you looked at the Linked posted. Maxed wattage of fans are 32 each using high setting. And as stated before, dont have lots of money to spend and wont be using system much
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: New to Solar Power
    Zakarume wrote: »
    Live in Missouri. Southwest Area. Up to 10 hours at night will be using the batteries. Fans are AC if you looked at the Linked posted. Maxed wattage of fans are 32 each using high setting. And as stated before, dont have lots of money to spend and wont be using system much

    Problem.
    32 Watts * 2 fans = 64 Watts.
    64 Watts * 10 hours run time = 640 Watt hours.
    85% inverter efficiency = 753 Watt hours.
    753 Watt hours / 12 Volts nominal = 63 Amp hours used.
    50% maximum DOD of battery = 126 Amp hour 12 Volt battery minimum.

    Now what will 45 Watts of panel do for charging that much battery? Not a lot. 2.5 Amps at best is <2% peak charge current. In other words maintenance level, not charging. You'd need three times as much panel for that.

    Here's another way of thinking of it: 45 Watt panels divided into 640 Watt hours used equals 14 hours of full sun on panels to replace the power without accounting for any losses. That isn't going to happen.

    So whereas it is entirely possible to run those fans all night from a battery, those panels aren't going to recharge a battery that will do the job. Options: alternate charging source such as small generator, larger batteries, slave girls to wave palm-leaf fans all night.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: New to Solar Power
    Zakarume wrote: »
    Live in Missouri. Southwest Area. Up to 10 hours at night will be using the batteries. Fans are AC if you looked at the Linked posted. Maxed wattage of fans are 32 each using high setting. And as stated before, dont have lots of money to spend and wont be using system much

    DON'T DO SOLAR!!!

    If your only going to use this for a short time, a few times a year don't do solar! at 32 watts, running a motor off an modified square wave inverter, you will loose power (wattage) with motor and inverter, think close to 50 watts an hour. Now does at least checking out the o2cool fans seem interesting? I've been there and done that, I checked every single small fan for wattage in several stores. Please at least check it out. These would run directly off the 12 volt DC at 8 watts.

    Marine batteries have minimal life and storage capacity in solar applications, particularly avoid any that have 'starter' in the title. Pick up a couple Sam's Club or Costco 6v golf cart batteries. Run in series they will provide about 220 ah at 12 volts 1/2 of which you can use. If of course you want to not use the AGM batteries I suggested previously. If fans are your only load either of these will be fine. You might try Battery Outfitters, a local chain for golf cart batteries, ask for Trojan 'black box' golf cart batteries, tell them it is for a new installation and ask if they will wave the core fee, they will in Columbia and perhaps at other locations. Might be the cheapest option.

    Charging the batteries with an AC battery charger is your best bet! I don't know how long you want to camp for, but these should provide you with a long useful life.

    If you get to Columbia MO much PM me, I might be able to give you some things to help you out.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: New to Solar Power

    I was pretty sharp about not doing solar, but I didn't explain why. Solar is very good at providing a small about of electric consistently over many years, but not very good at providing a lot of electric over a short time. I guess you've seen this in the responses you have gotten.

    This is similar to why you don't want to use a marine battery, typically they are a compromise at best. Any designed with starting(having a CCA rating) are not much better than a car battery, they need to be able to deliver a lot of energy at once, not a long slow drain...like a golf cart.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • AuricTech
    AuricTech Solar Expert Posts: 140 ✭✭
    Re: New to Solar Power

    Given Zakarume's application and budget, it appears that Zakarume can't really go for a larger PV system (although, if Zakarume can return the Harbor Freight system for a refund, a Renogy 100-Watt portable PV system can be had at not much more than the 45-Watt Harbor Freight system). That being the case, perhaps we can address the load end of the equation.

    If we assume that Zakarume buys a 20AH 12V battery (I thank PNjunction for pointing out my error) that his Harbor Freight system can reasonably support on about 4 hours of equivalent direct sunlight, Zakarume will have, at most, about 10 Amp-hours per night with which to work.

    Zakarume's initial plan was to run two 32-Watt fans (120VAC) for up to 10 hours per night. As Cariboocoot pointed out, that Harbor Freight PV kit simply can't support 640 Watt hours of power consumption.

    What if Zakarume used more fans, each of which consumed far less power? A USB-powered fan would likely be rated at about 2.5 Watts (500 milliAmps @ 5VDC), so 10 of them would still require less power than even one of Zakarume's intended fans. Depending on the layout of Zakarume's pop-up trailer, four USB-powered fans may well suffice to keep everyone comfortable. If so, that would reduce the load to about 100 Watt-hours, which would mean just over 8 Amp-hours from a 12V battery bank.
  • Shadowcatcher
    Shadowcatcher Solar Expert Posts: 228 ✭✭✭
    Re: New to Solar Power

    There are two parts to the equation, energy generation and conservation. We have a large teardrop which has roughly the same roof area. We have a single 185W high voltage panel feeding a 150AH AGM battery that supplies all our needs. For your situation, infrequent use, I would ditch the solar idea all together. Using anything that has resistant heat is a no no i.e. even a coffee maker. We used LED lights exclusively (Much lower power consumption) and computer case fans (Much Much lower power consumption than a 120V AC fan) and dirt cheap. We have a 300W inverter that is used for the TV and lap top (I could have gotten a 12 charger/power supply).
    Now for the generation part, a pair of battery cables from the tow vehicle to the trailer battery will do the trick. Our Subaru uses about .36 gallons per hour at idle. You to need to bring the battery up to 100% SOC with the on board converter or a battery minder of some sort with some regularity.
    Homework http://www.solar-electric.com/deep-cycle-battery-faq.html
  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    Re: New to Solar Power

    Ok i decided i am not going to use the 45 watt harbor freight in my camper. I decided instead to use https://www.renogy-store.com/100W-Suitcase-p/kit-stcs100d.htm and 2x 12v Batteries. I need to know a good mid grade type of batteries to get. I dont want Walmart Battery and cant afford the Trojan batteries. What would you recommened?
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
    Re: New to Solar Power

    We're still winging it.

    That being said, why not get a UPG UB-12500 agm right here conveniently. (50ah capacity).

    Try just one and see how that goes. If you kill it from neglect or insufficient charge, you won't be out much. Your insistence on using "2x" batteries is just going to end up in a "deficit-charge" scenario, even with the Renogy folding panel, and your own solar-insolation conditions (which in winter will be about 3 hours max at your MO location.)

    In your case, less is actually more! Maybe even a UB-12350 (35ah) is the better bet!
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: New to Solar Power
    Zakarume wrote: »
    Ok i decided i am not going to use the 45 watt harbor freight in my camper. I decided instead to use https://www.renogy-store.com/100W-Suitcase-p/kit-stcs100d.htm and 2x 12v Batteries. I need to know a good mid grade type of batteries to get. I dont want Walmart Battery and cant afford the Trojan batteries. What would you recommened?

    What kind of budget do you have?

    Your energy budget, while still depending on usage, will vary depending on how many consecutive days you hope to use them, If your out just for weekends, a 5% charging rate would give you an appropriate size around 120amp hours, while a week out(depending on more recharging from the solar panel) will give you a 10-13% charge rate or around a 50-60amp Hour battery.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • AuricTech
    AuricTech Solar Expert Posts: 140 ✭✭
    Re: New to Solar Power

    Before you spend any more money on a system, you need to ask yourself this question:

    "What do I really want from a photovoltaic (PV) system?"

    If your answer is along the lines of "I want to be able to keep my battery charged when I go dry camping for more than a day or so," then the Renogy 100W folding-panel kit is an adequate solution, especially if you use 12VDC fans (why incur conversion losses from DC to AC if you don't need to?). For a system built around a Renogy 100W folding-panel kit and a matching 12V 50Ah battery, I'd only be willing to use a small inverter (up to about a 150W pure sine wave inverter that can be plugged into a standard 12V cigarette-lighter-style outlet) during hours of decent insolation, unless I knew that I would soon be recharging my battery on-grid when I arrived at home.

    OTOH, if your answer is along the lines of "I want to experiment with PV systems, so that I can learn about them and eventually build a larger off-grid system," then you'll be better off building your own system. Building a PV system from scratch may cost more than an off-the-shelf system like the Renogy 100W folding-panel kit (it may also cost less, since you would be selecting its components yourself, instead of buying a package solution), and it certainly will take more work on your part. In the end, however, you'll understand a lot more about how to design a PV system that keeps your batteries happy (and batteries in a PV system are like Mama in a family, or First Sergeant in a military unit: "if the batteries ain't happy, ain't nobody happy!" ;) ).

    ETA: When choosing batteries for any renewable-energy system, stay away from any batteries that include the words "cranking Amps" anywhere in their description (even if they also use the words "deep-cycle" in their description). Such batteries are optimized to start engines; as such, they are ill-suited for RE applications.
  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    Re: New to Solar Power

    Ok thanks to everyone. I have changed my mind and i am going with 2 12 volt batteries wired in parallel to increase AH Rating along with https://www.renogy-store.com/100W-Mono-Start-Kit-p/kit-starter100d.htm. Just a note. This setup is to start out. I will had another panel in future
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: New to Solar Power

    I doesn't appear to be badly over priced as some 'starter kits we've seen, I guess you've read through the replies and understand the charging rates as applied to the batteries your getting.

    There is a Battery Outfitters in Joplin; Map

    The one in Columbia will wave the core charge for new installs, I suspect it would be the same there. They stock AGM batteries in various sizes, though I don't know if the charge controller will support AGM batteries. If your going to do Marine batteries (against pretty much everyone here's advice) They stock those as well as 6v 'black box' Trojans which are comparable in price and quality to the Sam's club 6v GC(golf Cart) batteries. 2 in series will give you 215 ah 12 volt battery and about a 2.5% charge rate. There are 12 volt flooded batteries around 100 volts, which would be a better fit if your going to charge during the week for weekend camping. Longer periods of camping and I would look to add that panel quickly.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.