Results 1 to 7 of 7
Like Tree5Likes
  • 1 Post By Fatman
  • 1 Post By Malikada
  • 1 Post By Fatman
  • 2 Post By TheMagicDragon

Thread: Battery charging using solar

  1. #1
    AVF Regular
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    145

    Battery charging using solar

    Not sure if this is the right sub-forum for this, mods please move if it isn't.

    I have been toying with the idea of using solar to keep my battery charger going, I figured there would be kits available at jaycar or bcf that would have solar panels/regulators/batteries/converters but it doesn't really look like there is that much available in this space. So I suspect that this is much more complicated or expensive than I thought. I am in a rental property so am not looking at turning my roof into a solar array.

    So my question is has any attempted (or succeeded) in setting up a mini solar powered system for charging batteries/phones/tablets, or is this just a silly idea that should be abandoned?

  2. #2
    Super Moderator
    Join Date
    Aug 2012
    Location
    Central Vic,up near the Murray
    Posts
    17,897
    Hey Mal, I dabble in a bit of solar here and there, and the cheapest way to set something up is by components rather than a ready made solution .
    Most of the ready mades are either uber expensive or cheap and nasty way underpowered .
    It takes a bit of forward thinking and a bit of math to sort out ... first of all you have to figure out how much electrical power you are going to be taking OUT of a system , and then work your way up to how much do I need to generate it and what do I need to store it?
    Most electrical solar stuff centres around watts ... and the most important thing to realise is that everything is quoted in "best case" figures ... so if you buy a 20W panel this means at the right temperature, in the right light it will give you 20 watts output... if the panel is fixed , then its only going to give you close to that for a few hours a day in winter and a few more in summer depending on the correct orientation ...
    Now that said a 4 Amp charger peaking at 4.2V will put close to 17Watts into a battery while doing so a 2A one will be feeding 9 watts or so ...
    Now the balance to any solar system means putting more energy INTO storage than you take out ( and you have to allow for inefficiencies and losses )
    SO if you charge your batteries with 17 watts for say 3 hours a day , you need to be able to put INTO the system the same or more ie generate 20W for the same time period .
    You will need a storage battery , this could be something as simple as a 7AH 12V battery or even a ok condition car battery, a solar charger regulator, ( as cheap or as fancy as you want, probably from ebay or a chinese store) and a panel ... the size of the battery and panel will depend on what you aim to do with it but if its just running a battery charger once a day for an hour or two to charge an 18650 then the 7Ah will be ok and a 20W panel should do it .
    To give you an idea I run a 6A draw 12v water pump for 4 hours continuous from a battery with a 200W panel that is overkill
    SO I am generating say 180W over a 5-6 hour period into the system while taking 70-80Watts out of it ... this means the system is well overcapacity and the battery will always remain at capacity ( provided it is run in sunlight) but the battery being a 60AH one is capable of running the pump for up to 6 or so hours without input, longer will drain the battery too low and reduce its cycle life . If I do water ( use electricity negatively) say at night , then the system will put back the energy I used during the day and store it
    Its all about balance , so to achieve that you need to know whats coming out of the system to figure out what you need to put in
    Malikada likes this.
    EPM V2-18490 (X2 ),GP Spheroid V2.5 and GP Piccolo V2.5 ,BBCB, Provari mini's, REO mini V2.1, 18490 REO , Jazz Carto Pipes ( fitted with GA tank and churchwarden stem Totally Evil!!! ), Meerschaum pipe ,e-holly35W,Phideas, AIOS,Taifun atties, PC Pipe mods.PC Squonker, Svapiamo squonker, GP Paps Heron combo.

    Vaping since 2007 totally smoke free since 2011


    AVF Rules , Read and understand them

  3. #3
    AVF Regular
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    145
    Thanks for the reply fatman, this is sounding like it is definitely something that I can start and then abandon when I get half the pieces!
    I was kinda hoping there would be some nice all-in-device that would accept power from the panels, store it for me, and then have an output ready for when I wanted to drain it.

    The battery charger I am going to be using asks for a 5V 4a input with a max output of 4.2V 2a (dependent on the slots in use). Given that it will only be used part of the day (generally when the sun has gone down) I will be using the panels to charge a battery and then using this to power the charger. One of my concerns is having the panels always connected to battery, I assume it is bad practice to keep on charging a charged battery, and also the charger draining the battery below a reasonable threshold (or even the battery charging the solar panels when the sun goes down) I guess the regulator you mentioned will take care of this and is probably one of the most important components.
    Dhufish likes this.

  4. #4
    Super Moderator
    Join Date
    Aug 2012
    Location
    Central Vic,up near the Murray
    Posts
    17,897
    This is where the regulator charger comes in ... it maximises the charge to the battery from the solar panel ( for instance most 12V panels actually output up to 18V) so it regulates this down to a correct charging voltage (say 14V ) and they are diode protected so the power only goes into the battery and not out back to the panel when they are not charging.
    They are also nifty in that they have a voltage sensitive OUTPUT which is where you plug your charger into ( not the battery itself) and they will only drain the battery to a preset level 11.1 V usually and then isolate the load ( your charger being that load )



    Something like this with an LCD lets you know whats happening
    LCD 10A 12V 24V PWM Solar Panel Battery Charge Discharge Control Regulator DA | eBay

    There are cheaper ones without the LCD but you have to trust they are doing it right without a way to check them ( other than manually metering them )
    A decent panel , one of these and a battery and you are set
    Malikada likes this.
    EPM V2-18490 (X2 ),GP Spheroid V2.5 and GP Piccolo V2.5 ,BBCB, Provari mini's, REO mini V2.1, 18490 REO , Jazz Carto Pipes ( fitted with GA tank and churchwarden stem Totally Evil!!! ), Meerschaum pipe ,e-holly35W,Phideas, AIOS,Taifun atties, PC Pipe mods.PC Squonker, Svapiamo squonker, GP Paps Heron combo.

    Vaping since 2007 totally smoke free since 2011


    AVF Rules , Read and understand them

  5. #5
    AVF Newbie | Be nice to me
    Join Date
    Nov 2015
    Location
    Pilbara WA
    Posts
    9
    I setup a micro system in my garden shed, mostly for lighting but it charges my phone etc if needed.
    Im running 20w of solar panel, a single 9ah battery (might be getting another just for extra capacity) and all the obligatory charge controllers etc all mounted in a large electrical junction box (approx 250mm x 200mm x 150mm)
    I have a three way outlet (one cigarette lighter outlet, one twin usb and one voltmeter) bought from ebay mounted in it.
    Total cost was approx $130.
    More than enough to charge phones, ecigs etc and run some led lights at night.
    Would pot pics but not sure how
    Fatman and Malikada like this.

  6. #6
    AVF Regular
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    145
    Thanks for the info, this is all sounding very doable, although I have hit one speedhump and she might take a bit of convincing that the house isn't going to burn down

  7. #7
    AVF Regular
    Join Date
    Jun 2011
    Location
    Bayside, Melbourne
    Posts
    2,544
    Reckon this would do the job and not outrageously expensive
    Solar Power Pack with LED Lights | Battery Chargers | Solar Power | Ecotech | PRODUCTS | MB3697 | Jaycar Electronics

    at $139.00 its decent value and reckon you could replace the powerpack with one of those Automotive jumpstarter packs at any time. the included Solar panel would charge my jumpstarter going on the specs and it's twice the output and has 3 USB ports and 2 lighter sockets and a built in LED worklamp

    if you want to build your own
    1 of these http://www.jaycar.com.au/Ecotech/Sol...V-10W/p/ZM9051
    1 of these http://www.jaycar.com.au/Ecotech/Sol...anels/p/AA0348
    then add your own battery and associated connections but will probably work out more expensive unless you've got 12V devices to plug in as you'll have to do some Voltage conversion. That said, Inverters are pretty cheap now days and will give you 240V plugs
    Last edited by D1git; 01-12-15 at 09:59 AM.
    Quit date : 10/5/2011

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.4
Copyright © 2019 vBulletin Solutions, Inc. All rights reserved.
Search Engine Friendly URLs by vBSEO 3.6.0
All times are GMT +11. The time now is 01:40 AM.