As someone who bought a 10 year old junk rig BC20 nearly 2 years ago for restoration to its original configuration, because it seemed(NB) like a bit of a bargain, now that I am ready to launch, going electric 'on the cheap' has become my next 'ambitious' venture.
Having surveyed these columns, the market and tried a 1kw Epropulsion in open water, my conclusions are:
- a 1kw Eprop/Torquedo is not enough for a 1000kg ballasted/laden boat in the strongly tidal waters of the Thames estuary, where encounters with heavy commercial traffic in a swell are not unusual. The next up 3kw variants are too expensive for me at £2300+ without battery
- in these conditions, none of the outboards with built in batteries offers enough endurance on one charge for a full day out, and the cost of additions is excessive per kw/hr compared with standard lithium ion batteries
- boats with cockpit outboard wells, like the BC20, could do without a large power/battery head and/or long shaft to trip over. Why should compact, light e propulsion imitate the traditional petrol formula?
The requirement might best be met by an electric pod motor on a minimal vertical slide, with around 200-250ah (24v) of lithium ion batteries cabin remotely mounted in the vacant area under the cabin entrance, where their 40kg weight might replace equivalent water ballast, while enabling removal for charging in the absence of local power points. Rob Johnstone's contribution to the thread on Electric Pod Drives (31 October 2023) points the way. The problem is that the available 3kw pods cost about the same as e outboards, leaving aside the fabrication of a sliding mount and the batteries.
Salvation, for me at least, may come in the shape of Haswing's Protruar 5, a 2.5kw/24v outboard, with a small head and a leg that offers both a sliding and tilting option. This can be had for about £700 and 2x100ah 24v IP65 lithium ion batteries for about £1700. This provides around double the thrust of the Eprop/Torquedo 1kw options, at least twice the range at equivalent thrust with these batteries, with minimal cockpit intrusion. Not cheap at £2500 all in, but at 2x the cost of a new replacement for my ageing 5hp two stroke, the margin is worth it for lower running costs, no smell/noise and first time starting with low maintenance. Haswing has been around for longer than most in USA and Germany with their trolling motors for fishermen and enjoy a good reputation for robust reliability.
But there's a catch. The 1m shaft is far too long and cutting it to around 50cm will invalidate the guarantee. It's doable diy, according to Haswing dealers and there are examples involving comparable models on the web. The task involves removing the head (2 screws), cutting the tubular SS shaft to the desired length respecting the minimum imposed by the sliding mechanism, and shortening the 3 wires from the direct drive motor to the head. I have ordered one and will test it thoroughly, before hacking it, to ensure the guarantee is unlikely to be needed. Watch this space for updates on the execution and the inevitable problems.
We all know that a boat is a hole in the water into which you throw money. Let's see if I can keep it down to a compact sack or two this time.
