20 watt solar panel,contoller and battery

easytimeasytim Solar Expert Posts: 57 ✭✭✭✭
Can someone guide me to a good cheap 20 watt solar panel and controller, is there such a thing? I was looking at the solar panels at Harbor Freight.






I'm wanting to power 8 maybe more - 3 x 1 watt MR-16 LED lights using the 12vdc LED light in picture below, these lights put out about 30+ watts of light - 240 lumens is very bright.

High Power White LED Spot Light Bulb Lamp 12V 3W MR16 $12.00 I have two of these 1 warm and 1 cool
http://cgi.ebay.com/High-Power-White...3286.m14.l1318


This one cost double $28.00, but the light is more than double than the 3w single LED above, its very bright !!!!!!!!!!!! MR16 LED CREE WHITE 3x1W(3W) AC DC 12V XR-E 240 Lumen
http://cgi.ebay.com/MR16-LED-CREE-WH...em190239759370

I'm wanting to use these lights also later use these lights in my family room soon as I find a good combination and some cool looking fixtures to put them in that will accept a MR-16 bulb


For reference purposes, a standard 40-watt incandescent A-bulb (the familiar pear shape) puts out about 455 lumens



This is one way to do it

MR-16 to a standard Edison Medium Base (E-26) socket adapter by
Light It Technologies.
These are made in Montana and have clips which aid in securely
holding a two-pin MR-16 floodlight in place.
PRICE: ( LIT MR-16 ) $ 10.50 each
http://www.solarseller.com/halogen_b...ase__mr_16.htm








What I think I need is a 20 watt solar panel, controller and 12ah battery. I want to power my yard lights, 8 MR16's with solar, charge the battery during the day and use the MR16 LED lights at night. I only want them on for about 6 hours total, will I need a bigger battery?

Can someone guide me to a good cheap solar panel and controller, is there such a thing? I was looking at the solar panels at Harbor Freight

I have a couple of pictures of controllers. The one below on left is a CMP-20 and is for 20 amp price is $52.00


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Comments

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: 20 watt solar panel,contoller and battery

    here's the link to some pvs.
    http://store.solar-electric.com/1to39wasopa.html
    i suppose the one's from harbor freight could be used as well. none of them could be considered cheap as in price as pvs are expensive. look around and be sure it will output enough voltage as some of the used ones are of a design for lower output voltage (around 15v-16v) in the hopes of eliminating the cc. this is not a recommended move or pv.
    as to controllers i have heard the controllers from harbor freight are dinky, but i see in your photo that you have a sunsaver and another ? cc. as long as they work, and i know sunsavers do, then all is good. just in case here is the link for other ccs.
    http://store.solar-electric.com/chco.html
  • mike95490mike95490 Solar Expert Posts: 8,466 ✭✭✭✭✭
    Re: 20 watt solar panel,contoller and battery

    I would suggest a AGM battery (sealed), and a charge controller with an AGM setting. You would have an undemanding system, and keeping a single battery, I'd go for AGM. Less losses too, close to +95% efficient vs 80% with flooded cells. Maybe I'd suggest a bigger panel and battery, the system could be more versatile. Beware of leaving a light on while charging - charge voltages can be near 15V, which may be higher than the LED's can take.
    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 ,

  • easytimeasytim Solar Expert Posts: 57 ✭✭✭✭
    Re: 20 watt solar panel,contoller and battery
    mike90045 wrote: »
    I would suggest a AGM battery (sealed), and a charge controller with an AGM setting. You would have an undemanding system, and keeping a single battery, I'd go for AGM. Less losses too, close to +95% efficient vs 80% with flooded cells. Maybe I'd suggest a bigger panel and battery, the system could be more versatile. Beware of leaving a light on while charging - charge voltages can be near 15V, which may be higher than the LED's can take.


    I didn't know that about AGM batteries and I sure didn't know about an AGM setting. I won't be using lights when they are charging I'm sure. I want to put them on a timer and dusk to dawn. It will turn on only when it gets dark and then only run 6 hours from that time on every night.

    Bigger panel and battery, please give me an example of how much bigger.
    I'm going to take my time and do alot of reading, I can tell you the LED lights I got are awsome. They have made some great advances lately
  • mike95490mike95490 Solar Expert Posts: 8,466 ✭✭✭✭✭
    Re: 20 watt solar panel,contoller and battery

    > Bigger panel and battery, please give me an example of how much bigger.

    I'd guess at a 50A or even up to the full size 120A battery. There are several different mfgs, some approve of discharge down to 30%. 50 or 60 watt panel. Look for a good price point, don't limit yourself to a small one. (once your hooked, you will want to do more and more...)

    I've used a small mod-sine inverter to drive several strings of LED holiday lights, which are cheap, and look really nice.
    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 ,

  • easytimeasytim Solar Expert Posts: 57 ✭✭✭✭
    Re: 20 watt solar panel,contoller and battery

    Do you think this conbination would work well with a 50 watt solar panel.


    C12 Xantrex
    http://www.xantrex.com/web/id/71/p/1/pt/25/product.asp

    or maybe

    C40 Xantrex controller
    http://www.xantrex.com/web/id/72/p/252/pt/5/product.asp


    12vdc 79ah
    http://www.donrowe.com/batteries/8a24.html




    .
  • mike95490mike95490 Solar Expert Posts: 8,466 ✭✭✭✭✭
    Re: 20 watt solar panel,contoller and battery

    Depends on your budget !
    I'm going to reference the boards host as supplier.

    MK & Decka are same mfg:
    http://store.solar-electric.com/de8a78ampho1.html for a couple bucks less.
    Buying the battery local, saves on shipping.


    For a small system, the C12 is perfectly capable, unless you want to move up to a MPPT style charge controller. The C12 has some nice features, but you would have to check the specs to see if it has an AGM preset. I know you can "fine tune" the pots inside for a precise voltage.
    The http://store.solar-electric.com/mosumpsochco.html SunSaver is a good MPPT controller, depending on the PV panel you get, the higher voltage panels [ >19V] work better with a MPPT controller, the lower voltage [16-19V] better suited for the old PWM controllers (C12) Of course, the extra $ for the MPPT means you get a better power match from the panel to the batteries. If you are in a cold winter area, the MPPT also squeezes a few more watts out of the panels in the cold. helps make up for the shorter days.

    Panel wise - look for the good price point, the 35W panel may be a great buy, compared to an 18 W It's easy to get jazzed about solar, and then find out that you have not got enough PV to do all the extra things you want.

    Mike
    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 ,

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: 20 watt solar panel,contoller and battery

    "the lower voltage [16-19V] better suited for the old PWM controllers (C12) Of course"

    not totally true as i use mppt on unisolar pvs and it works just fine at 16.5vmp, but i'd recommend 17vmp or higher that should be used with mppt ccs with 12v battery systems. if you need a blocking diode because of a cheap cc then add another .5 to .7v to the vmp due to the drop on the diode. most good ccs will stop nightime draining of the battery so a blocking diode is not needed with them.
  • easytimeasytim Solar Expert Posts: 57 ✭✭✭✭
    Re: 20 watt solar panel,contoller and battery
    mike90045 wrote: »
    Depends on your budget !
    I'm going to reference the boards host as supplier.

    MK & Decka are same mfg:
    http://store.solar-electric.com/de8a78ampho1.html for a couple bucks less.
    Buying the battery local, saves on shipping.


    For a small system, the C12 is perfectly capable, unless you want to move up to a MPPT style charge controller. The C12 has some nice features, but you would have to check the specs to see if it has an AGM preset. I know you can "fine tune" the pots inside for a precise voltage.
    The http://store.solar-electric.com/mosumpsochco.html SunSaver is a good MPPT controller, depending on the PV panel you get, the higher voltage panels [ >19V] work better with a MPPT controller, the lower voltage [16-19V] better suited for the old PWM controllers (C12) Of course, the extra $ for the MPPT means you get a better power match from the panel to the batteries. If you are in a cold winter area, the MPPT also squeezes a few more watts out of the panels in the cold. helps make up for the shorter days.

    Panel wise - look for the good price point, the 35W panel may be a great buy, compared to an 18 W It's easy to get jazzed about solar, and then find out that you have not got enough PV to do all the extra things you want.

    Mike



    Hello Mike,

    From what I have been reading the SunSaver is a good MPPT controller and they have software to monitor charging. I like the idea of monitoring the charging.

    I think the SunSaver is the way to go

    I hope I'm right on all of this
  • mike95490mike95490 Solar Expert Posts: 8,466 ✭✭✭✭✭
    Re: 20 watt solar panel,contoller and battery
    easytim wrote: »
    I hope I'm right on all of this

    I hope I'm right too ! I don't intend to steer any one wrong, double check my math, see what other's comments are, don't take my word as gospel.
    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 ,

  • easytimeasytim Solar Expert Posts: 57 ✭✭✭✭
    Re: 20 watt solar panel,contoller and battery
    mike90045 wrote: »
    I hope I'm right too ! I don't intend to steer any one wrong, double check my math, see what other's comments are, don't take my word as gospel.

    I have been doing alot of reading, I think your right on the mark
  • BB.BB. Super Moderators, Administrators Posts: 29,698 admin
    Re: 20 watt solar panel,contoller and battery

    The one issue I will warn about--computer monitoring of system performance...

    A small laptop will use around 20-30 watts--Run that 24x7 (automatic logging), and you are around 500 Watt*Hours per day... A SunSaver MPPT charger with 200 watts of solar panels (maximum for 12 volt system)... It may generate about 500 WH of useful power per sunny day. Pretty much running your solar system to run the computer monitoring your solar system.

    Certainly to update the Charge Controller's settings and check up on it while you are using the computer anyway--not a problem... But with solar (and especially small solar)--conservation is mandatory. Turning off/using smaller/etc. is the way to go to make solar (and off-grid solar) a reasonable solution for electricity.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • easytimeasytim Solar Expert Posts: 57 ✭✭✭✭
    Re: 20 watt solar panel,contoller and battery

    BB,

    The monitoring of the system would be an easy way to check on the system. Only a 10 min. look on the computer is needed .


    Not meant to keep looking , only take a peek:D



    .
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