[Octopus]

Originally Posted by VERTIGO

My first post here but love this site. I would like to start out by saying thank all of you that are buying/supporting the hybrid conversions. Allot of "risk" involved in being the first ones, but without you this technology will not come out. If I had the $$ I would join you today but still 6 years out from retirement (Army) so maybe I will be buying one of your boats down the line.

Welcome to the forum James.

Originally Posted by VERTIGO

I read on the G2 upgrade and the part that gives me a bit of confusion is the ability to run at 100% for 10 min, what is the limiting factor that keeps you from running at 100%?

I think the "10 minutes at 100%" you are referring to is when you use the emergency boost facility. By pushing this button you get full power from the batteries for ten minutes. The reason it is limited to ten minutes is that this level of draw can damage the batteries if sustained for too long. So, you use it to get out of trouble and no more. The motors are bullet-proof and can, in theory, sustain full power day and night for years, it is the lack of available electrical power that limits sustained top speeds.

Originally Posted by VERTIGO

Is there anyway to increase the performance of the motoring? Example: A swap for a larger prop, yes at the cost of sail speed, but part of my plans are to travel up the Mississippi to Minnesota. I did this several years back on a 28 Morgan with a 9.9 outboard, and it took some time to get down the river. On this next trip I will want to go up and down. So I think if I knew I was going to be doing more motoring at some point in time I would swim under and swap out props?

What sort of speeds do you want to motor at? In calm conditions a lightly-laden 420 hybrid will motor for approximately 1 hour twenty minutes at 7.4 knots, assuming you start with fully charged batteries and have the generator on throughout. After an hour and twenty minutes the level of charge will have dropped to 60%, so the speed drops to 6.5 knots, whilst the batteries are being gradually recharged back up to 80%. Thereafter, the hybrid can motor all day at 6.8 knots until the fuel runs out.

I doubt that larger props would improve your speed, unless you matched them with larger electric motors and larger generator.

I'm no marine engineer, but, in my view, the measure that would bring the largest improvement in motoring and sailing performance would be to refashion the transoms, adding 3ft to the LOA and remove the bulge below the waterline. The 420 develops a lot of turbulence at the stern, which cannot be efficient. I blame this on the barrelled out sterns and submerged transoms, which bear the hallmark of a last minute design alteration to carry the battery weight.

Originally Posted by VERTIGO

Also was wondering what the life expectancy Lagoon is saying their batteries are going to get??

The life expectancy of the standard lead-acid batteries depend very much on how you treat them. If you regularly allow them to be deeply discharged or leave them in a discharged state for long periods then they will not last as long as if you keep them well topped up (both in terms of the level of charge and the level of the battery fluid). I expect those on my boat to last five years. They are twenty months old and 'as good as new' according to the Lagoon technician who installed our upgrade. We rarely motor on batteries alone.

Chris
Octopus, L420 Hybrid
Isle of Arran, Scotland