Monthly Archives: July 2013

High Performance Low Weight Lithium Batteries Solar & Fuel Cells

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High power low weight lithium batteries fuel cells solarpanelsforcamper trailers and caravans This eBook steps through 12 chapters on the design of high performance electrical systems. The ultimate test of a high performance system is if it can comfortably operate a regular 2.2kW Airconditioning system in a National Park in Northern Australia with no generator.

High performance electrical design is measured by power/ weight. In Caravans and Camper Trailers, the lighter the weight, the easier to tow with better accessibility to the best camping spots.

The core question when investigating your requirements is to ask just how much of Australia do you want to experience and how independent do you wish to be? 

High performance energy comes at a price. Is it worth it?

The eBook discusses in more detail the 3 fundamental aspects of “high performance” power and energy storage devices in RV’s and how they dove-tail together as a system. You can then decide if it is worth it for your travels!

The requirement for energy while camping appears to be doubling every 5 years. This trend will continue. However, the number is now getting much bigger requiring more space and with this, the penalty of more weight if technology doesn’t change. 

The table below shows a prediction for the next 5 years for full size off road caravans.  

Full size Off-road Caravan





Large Solar Capacity





USABLE Battery Capacity

70 Amp-hr

110 Amp-hr

210 Amp-hr

450 Amp-hr

Nominal Battery Capacity

if Batteries are AGM

140 Amp-hr

220 Amp-hr

400 Amp-hr

800 Amp-hr

Nominal Battery Capacity

if Batteries are Lithium



250 Amp-hr

480 Amp-hr

A good question is why would this be the case with more energy efficient products? 

Simply put: more people want to stay in more remote areas for longer periods, away from facilities. More people want to carry food and beverage for longer avoiding the high cost of convenience food in remote areas. More people want to keep track of major media events and their favourite sporting team while away traveling. In doing so, people travel for a little longer and in much more comfort. 

There are over 500 National Parks in Australia with a large number having regulations on limited or no generator use. Camp for a weekend with no Generators at all and you really feel you are camping!

High performance is measured by power/ weight. In Caravans and Camper Trailers, the lighter the weight, the easier to tow and you have better accessibility to the best camping spots.

The tables below re-state this trend of solar panels and batteries into  a combined weight. You can see that if there isn’t a switch to new technology by 2018 the weight carried is obscene. In fact some large off road caravans carry this much weight today! 

Full size Off-road Caravan





Nominal Weight  if Batteries are AGM and Solar panels* are glass

 95 kgs 

 156 kgs

 288 kgs 

 576 kgs 

Nominal Weight if Batteries are Lithium, Solar panels are Super Thin Alloy



 44 kgs

 86 kgs 

As a lot of readers may have off road camper trailers, reducing the capacity by 50% to the previous chart gives these weights:

Off-road Camper trailer at half above capacities





Nominal Weight if Batteries are AGM and Solar panels* are glass

 47 kgs 

 78 kgs

 144 kgs 

 288 kgs 

Nominal Weight if Batteries are Lithium , Solar panels are Super Thin Alloy 



 22 kgs

 43 kgs

high performance solar reading for off road caravanA Quick Lesson in Solar Performance:

This screen shots says it all. 

There is an effective capacity here of 78w created by generating 5.9a at 13 volts. Just multiply the 2 together and you get close the 78w. There is none of the power loss of a regular solar controller.

Then look at the panel voltage of 38V. This is much higher than you would normally see. Why?

If you have 500w of solar on the roof of an off road caravan, then at the usual 18-19v supply, the current would be 25+ amps. This is a lot of current traveling done from the roof to the batteries. 

Unless the cable size is a whopping 20mm square or so, you are losing a lot of energy plus there is a safety issue with that much current sizzling around your ears all the time. 

The solution is to go up to the maximum permitted by law for “low voltage” which is 49v. In the example above, the roof current is only 1.6 amps at 38v.

Continuing a quick study in solar, there is a special type of solar controller called an MPPT Solar Controller. This stands for Maximum Power Point Tracking. Here is an explanation in lay terms.

An ordinary solar regulator or controller takes the power from the solar panels and reduces it to charge the batteries. Solar Panel voltages for these controllers is typically 18-21 Volts. What these controllers do is effectively throw away the power above the charge voltage of 13.8 or 14V. So with a standard controller you can lose up to 30% of the charging current.

Continue to read the rest of this eBook which has these chapters:

  1. Preamble:  The Future in High Performance Energy Systems
  2. Operating a full power Air-conditioner on Batteries 
  3. Why are we using more power? a 20 year trend.
  4. Performance is measured by Power to Weight
  5. Examples of Low weight Solar panels
  6. Designing a Lithium System to avoid danger
  7. Generating Power with Solar
  8. A Quick Lesson in Solar Performance?
  9. MMPT Solar Controllers are a Must!
  10. Storing the electrical energy in Batteries
  11. Design of Lithium Systems
  12. Design of Charging systems for Lithium Batteries
  13. Storing the electrical energy in Methanol – Fuel Cells
  14. Easy to use charging systems
  15. A summary of this eBook
  16. Addendum for high end Camera Users

Click here to download this eBook:

A High Performance Energy System is measured by High Power, Low Weight.Using Super Thin Solar, Lithium Batteries, Fuel Cells, Integrated togetherDownload this eBook to see how we do the design!

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