If you haven't tried electric drive before it will be a revelation compared to
petrol motors. The first thing you will notice is how easy it is to use, just
twist and go - no petrol spillages, fiddling with chokes or knocking out
other passengers when you pull the start cord! The second thing you will
notice is the relative lack of noise - you won't scare off wildlife, and you 
can hold a conversation without shouting. In fact the loudest noises you
will hear are water sloshing against the hull, and a very mild transmission
whine from the reduction gearbox.

Any of the integrated battery models (401 Travel, 801 Travel, 503 Travel,
1003 Travel) will give you a couple of hours at 3-4 knots in the Trio, or up
to 3 hours from the 1003 (which has a higher capacity battery). The 801
and 1003 can achieve higher speeds, up to about 6 knots, but with much-
reduced run-times - range reduces exponentially as you speed up.

The simplest and cheapest installation with external batteries would be a
Torqeedo BaseTravel 401. This runs at 12volts, which means it only needs
one battery, and we can mount this in a box under the aftermost seat in
the stern section. With a 113 amp hour battery (which just fits) you will
get a realistic operating time of about 5 hours on half power, equating to
a range of 15-20 miles. This option is priced at £950 all-in.

(Please note that all range/speed figures depend on the load - ie weight
of passengers and gear - wind, tide, battery condition etc. We try to be
realistic, not crazily optimistic.)

The next option up would be the BaseTravel 801, which requires two
batteries wired in parallel because it runs at 24 volts. These can be fitted
in a box that mounts under the seat in the middle section, putting the
weight (approx 50kg of batteries) low and central in the boat, right where
it should be. The 801 is double the power flat out, but consumes the same
power at the same speed as the 401, so you would have a potential range
at 3-4 knots of 30-40 miles, or perhaps 20 miles at 5-6 knots. Cost for
this is £1,175 all-in.

In both cases we would recommend 10 amp charger(s) which have the
potential to replace all the power you are likely to use during the day
overnight. They are £70 each but cheaper ones will be slower and should
not be left on much longer than the charging period (the ones we
recommend can, going to "float charge" mode once the battery is
replenished). The cost of the electricity will be barely measurable!

We can also turn the Trio into something of an "electric speed boat"
with the 2kW Torqeedo motor. She will then do approx 9knots, and as
this is a 24volt motor it would run off two batteries as above (obviously
draining them faster at higher speeds). The acceleration is virtually
instantaneous, and the combination of speed and virtual silence is
incomparable to anything else on the water.