How Long will the LEAF charge last?

    Now that we have figured out all this Solar Band stuff in "theory."  It is time to answer the question, "How long will my LEAF battery last?" in reality.

    Well if we are burning up 50 amps per hour and we have 400 amps, then we have 8 potential hours in hour battery bank for the LEAF.   But thats only if we burned our battery bank to nothing.  Thats not reality.  If you burn your battery bank to nothing it won't last very long.  

    Lets just assume we are going to only use 25% or 1/4s of the battery bank capacity at a time.  Leaving 3/4 left in reserve to prevent from over discharging.*  We then know the LEAF battery banks will give us 100 amp hours, 1/4 of 400, which will give us 2 hours of battery life.

   So the answer to "how long my leaf charge will last?" in answered.  2 hours @ 25% drainage

      one love till next time...





*Over time over discharging will shorten the battery life substantially.  So don't do it... ever.   Or else!!!  lol...

Designing a solar system Step 2 of 2 Batteries, inverters, and cells

    The last section we left off with LEAF needing 50 amps at 12 volts to power the band.  Now amps are per hour so when you say you need fifty amps, in technical terms you mean "50 amp hours."  Now batteries are conveniently rated by using... wait for it.... Amp hours!

    So, if you have a fifty amp hour battery, in theory it could run the band for an hour.  IN THEORY.  But in reality you won't get that much out the battery.  Here's why.  As a battery discharges it works harder and harder to maintain constant current levels.  Think of it like this.  A battery is like a water balloon, as when you first open the hole on the balloon it squirts out water fast, but then slowly tapers off.  In order to get all the water out of the balloon you have to squeeze to get it out.  YOU CAN'T SQUEEZE BATTERIES.

    Now it makes sense to simply increase the battery size/capacity to allow a steady 50 amp current without draining it down more than 50% or half.  And draining batteries down to half capacity is not going to make them last too long.  Like the balloon, we would need a huge ass balloon to squirt a stream of water for an hour, but a big enough balloon could squirt all day without going low.

    So 50amp hours would require around 400 amp hours of battery capacity to run for an hour.

    A 400amp balloon... lol  This allows us to mess up and use 200 amp hours and still not go below 50% capacity on the batteries.  My batteries are all about 90 amp hours each, and luckily I have five old ones that together should get LEAF to around 400 amp hours.

                                   5 x 90 amphours = 450 amp/hour capacity

    Now how many solar panels do we need?

    It all depends on how fast you want to recharge the battery bank.

    "Battery Bank" is just jargon for the whole group of batteries you use.  My battery bank consists of 5 90 amp hour deep cycle marine batteries.

    For this system, if I can generate 200 watts per hour, then I will be golden.    Now this 200 watts only counts as 16 amps per hour or so, or in other words... 16amp hours per hour.  If we charge for 20 hours:

                                  20 x 16 = 320 amphours for or battery bank!

     Lets say we get 5 good hours of sunlight every day on average, and we charge monday-friday 5 days:

                                  25 hours per week    x   16 amp hours  =   400 amp hours!!!

    Well all you need is an inverter but lets wait till next time...  Let all the math sink in and go order your solar cells and or panels.  I make my own panels out of broken solar cells purchase from these guys Silicon Solar they are rad.

    So next time we will look at inverters and such...  Scroll down for the next blog.    

                One Love from LEAF   Leaf Music

  

Designing a solar system Step 1 of 2 How to convert 120V to 12V

    LEAF has decided to finally go solar.  For obvious reasons this move is necessary for us and the earth.  Now here's how we do it.  A solar system has three basic components.  Now some systems can get VERY complicated, so I like to keep to the KISS philosophy here.  (keep it simple stupid) And yes leaf might have to cover a KISS tune now... :)  

    Three components:

                  1)Solar Panel(s)-which generate(s) power from the sunlight

                  2)Battery(s)-which store the power generated by the panels

                  3) Inverter -which converts the power from 12Volt DC to 120Volt AC (house power)

    To figure out your system requirements you have to fist find out what your system requires now.  Our stripped down sound system including the P.A. the two guitar amps and all the pedals has a total draw of around 600 watts.  I find that figure out by looking at the back of my gear and there are labels which state the draw in watts.  Now watts are good, but we need to know amps.  This is easy. 

    Divide your total watts, in our case 600 watts, by the voltage, 120.  ALL HOUSE CIRCUITS DRAW 120 volts.*  You can use this figure always without fail.  

    So we have 600 divided by 120 which comes out to....  drumroll....  5.

    We will be burning 5 amps at 120 volts.  This is the information we need to go to the next stage.  Just divide watts by volts to get amps.  

                              watts/volts=amps

     So now we have 5 amps at 120 volts... But we are running 12 volt batteries which is pretty common and the most economical way of storing power considering one can be bought reconditioned or new for fairly cheap.  And when maintained they last beyond their service life.  At least that has been my experience.  

     If you notice 120 is exactly 10 times more than 12 then you are ready for the next step.  Simply multiply the 120 amps by 10 to figure out how many 12 volt amps will be needed.

    If you imagine a 12 volt system being ten times weaker (voltage wise) than a 120 volt system and therefore a 12 volt system will have to work ten times harder to match 120 volts.  Thats the theory here.  So... 10 times 5 equals 50.

                             5 x 10 = 50 amps at 12 volts

    That means every hour we have to create 50 amps to push our system without spikes or interruptions.  Ok so we know how many amps in a 12 volt system are needed to keep up with electric draw, next we need to figure out how many batteries will be needed to supply this miracle music!!!  

    Next post will be about batteries and solar panel requirements.  One love!

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