Selecting your solar charger / power station

Solar generator power station500 Watt Pedal Power Generator Charging Patriot Power Generator

SELECT A POWER STATION  / SOLAR GENERATOR

This content covers what to consider when selecting a  portable power station  to charge with  your pedal power bicycle generator system .   These are also called “Solar Generators”    or  “Powerpacks” There are a few major criteria that you will need to use to select your power station. 

  1. Traditional lead acid  battery or lithium battery 
  2. The Amp hour rating (Battery Capacity)
  3. The max charge Voltage
  4. The max charge current
  5. Built charge controller  or no built in charge controller
  6. The type of connectors needed to connect to the  power station
  7. Portability –    how easy is it to carry around.   
  8. How long it will take to charge 
  9. Whether or not to use for both solar and pedal power.
  10. Number of charge cycles you want 

The short answer:   If you do  not need portability and you are on a tight budget  you could use a  very heavy  lead acid  100 – 200AH  12V  marine deep cycle battery  for around $100 purchased from your local  automotive store.   This will give you the most  capacity for the lowest amount of money.    If you need something that is easy to carry around  then consider:

 The capacity of a power station is based on a term called  “Amp Hours” or more often mentioned as “AH”  .   Many manufactures  hide their low AH rating buy putting it into the form of WH (Watt Hours).   A 12V power station with a 10AH battery rating will be a 120WH rating.   (Watt Hours = Amp Hours x  12V Operating Voltage) .     So one can see that the number  120 is a much bigger then 10  and helps sell the product for the manufacture.     For those who are not familiar  with this term  here is a brief  explanation.   

If you have  a battery that  has a 50 AH  rating then that means  it can put out the following  Amperage:

  • 50 Amps for one hour 
  • 25 Amps for two hours
  • 10 Amps for 5 hours
  • 1 Amp for 50 hours

In other words  if you want to know how many hours  a battery power station or solar generator  will last at a certain current  or Watts  then you will need to divide the desired Amps output into the AH rating and that would give you the hours.    For example  a 100 Watt DC  bulb   running at 12V  will draw  about 7 Amps  of current.   This is derived by using the equation   Amps  =  Watts / Volts .    To solve for the number of hours  a battery will last  powering the 100 Watt bulb  at 7 Amps we divide 50 AH  by  7  an get about ~ 7 Hours . 

 

1)  Lithium vs  Lead Acid Battery

Lithium batteries  will eventually overtake  lead acid batteries  because of their size and weight being much less.  There are hundreds of companies popping up all over the place with new portable power station products.    Right now  there are few lithium battery power stations that are UL approved and we know that lithium batteries  can be unstable if they are charged with too much current and get hot – they can explode into flame.    We know that Samsung phones were not allowed on airplanes for a period of time for this reason.   

An extremely safe and low cost way to use Lithium batteries in a power station  /   solar generator is to limit the charge current and charge Voltage range to a very low level.   For instance  the Jackery portable power stations are extremely  popular  on Amazon  with over 500 sold.    These belong to the price range of under $500.    How did they minimize  the huge risk of Lithium  battery danger?   They limit the charge current to around 3 Amps so that it takes 2 to 5 hours  to charge their power stations depending which model you look at.    

If you want to be able to charge much quicker and efficiently  and use the full capacity of your  bike generator  or  solar array  then you will need to spend more than $500  and get a power station that can handle 10 to 20 Amps of charge current  and 0 to 100V DC  Voltage range.  These are rare and expensive now in 2021 but will be very cheap in 5 to 10 years.   

The only reasons to stay with Lead acid battery style power stations are:

  • You want a very cheap way to store energy
  • You do not want to carry around your power station
  • You want to be able to  charge with a lot of current 

If you would like more help picking out your power station  please text or call  or email.    Ask for Bradley