How far can I go?

We are just getting our first experiences of novice users driving the b-bug (electric buggies) as part of the trial we are running this summer.

The first question everyone (inevitably) asks is "how far can I go?" and that is a remarkably difficult question to answer!

In the case of the b-bug, a marketing executive (if The Prospectory included such beings) would tell you "oh, 25 miles for sure". A pessimistic engineer (having summed up your weight, the likely terrain on your chosen run and your probable driving style) might say "15 to be safe". Because with a battery-powered vehicle, it does "all depend".... To be fair, it's not simply an electric car problem, if you always drove your petrol car with only 2L in the tank, it would be very hard for anyone to tell you exactly how much further you could drive.

For the b-bug trial, we have signed up about 20 b-bug charge points in pubs, cafes, tourist attractions, etc across the Brecon Beacons National Park. These places welcome a weary b-bug and will happily plug you in for a 1-2 hour top up which will extend your range by..... um well, that's hard to say because batteries (I'm learning) take on charge at different rates depending on how empty they are (bit like people really). So, we estimate and tell people 4 miles/hr of charging maybe.

Then the problem gets worse - someone has topped up their battery for a "short while" and is now trying to figure out "so how far can I go NOW". It's not too bad if they plan to return exactly the same way as they came but even that's not true if the out journey was mostly downhill but drivers, unlike walkers or cyclists don't necessarily notice such facts! It's a bit like sailing out to sea with a pleasant offshore breeze and then turning and remembering that beating back to windward is much harder work and will take you a lot longer.

So being data hounding Prospectors, we've installed a Cycle Analyst in both b-bugs. This clever device displays every number you can imagine both as you drive along AND at rest - voltage, kWh, Wh/mile, Ampere hours and miles. I didn't even know what an Ampere hour was but now it's my main guide for how much power I might have left for my journey - I know if I've used up 30 Ah, then it's time to turn for home because the batteries can only produce about 60 Ah. It's become part of my everyday travelling vocabulary as have volts as the b-bug and I climb up a long, steep hill.

But the array of numbers seems more likely to bewilder rather than clarify the energy situation for our poor triallists. They weren't expecting to need an 'A' level in physics to get themselves home from a day out in Hay on Wye. Our best shot so far, is an empirical approach. We give them a graph (based on the 30 or more b-bug trips of all kinds we have done) and encourage them to check what the Cycle Analyst says the rest voltage is and read off the miles that has typically taken us (but notice the fact that the points on the graph are somewhat scattered!)

So, the trial IS an adventure and driving the b-bug is great fun. We have to hope that the holidaymakers taking part discover, like us, the thrill of the "epic" 20 mile journey and that they also share some of the fascination of how much energy is actually involved in moving our bodies and vehicles up and down the hilly lanes of the Brecon Beacons. With modern cars, we have no clue.

So, b-bug travel has something for everyone - the countryside lover, the explorer, the engineer, the physicist, the environmentalist or even (like me) the cognitive psychologist.

If you'd like to stay a few days in the Brecon Beacons and take part in the trial, then check out the details here.