PERRY'S POWER-PACK

Here's another classic Perry Product - a convenient source of electricity when camping.

A pearl of a Perry Product, the Power-Pack is a paragon of painstaking paraphernalia.

Enough panegyric*.

Born of the triple desires to:

1. bring chocolate back from Belgium without it melting;
2. have a better fridge when camping than a bag of cold water, and
3. to have a sustainable source of electricity when camping;

the Power-Pack forms the heart of a flexible source of electrical power.

The brief was to build a unit that could take a variety of electrical energy input sources (solar, wind and camping site hook-up) to charge a 12volt battery and provide both 12 volt and 240 volt outputs.

The 12v supply could then be used to run low energy lighting and a 12v fridge, with the 240v supply charging camera batteries, mobile phones and the odd piece of low-power mains equipment.

It all had to be compact and robust enough to be safe when camping. Since the fridge alone would quickly drain a vehicle battery the system had to be independent of any vehicle charging/power systems.

Photos above show the final device.

The general arrangement is shown on the left, with inputs at the top and outputs at the bottom.

Main internal components are:

1. the Residual Current Detector (RCD) and Miniature Circuit Breaker (MCB) to look after the mains input;
2. a battery charger to charge the battery when a mains supply is available;
3. the controller circuit for the solar panel and to protect the battery from over discharge, and
4. an inverter to produce 240v when there is no mains available.

Various switches control what goes on and devices have their own fuses. The standard 240v camping hook-up can be seen at the end of the PowerPack under the handle, (photo above right) and a pair of 3-pin sockets at the bottom of the panel. A bank of 4 12v sockets are at the top right of the panel. The quick-fit battery connectors are on a flying lead (photo above middle).

The complete set-up with fridge, PowerPack, battery and solar panel is shown in the bottom right photo.

I shan't bore you with the details, but the main conclusions from a year of research and experimentation are:

1. If you are only going camping for a short break (less than a week) it is easier and cheaper to just take the power with you that you need in the form of suitable lead acid batteries.
2. Home-made portable wind generators should be feasible, but typical camping seasons and locations make this option a poor provider of power (not enough wind on campsites in summer).
3. You would pay a fair amount for the same features if you just buy the relevant caravan/motor home/boat equipment from normal suppliers, but there is as yet no cheap d.i.y. substitute for photo-voltaic panels.

If you want details on any of this you'll have to ask.

* look it up yourself