ESPcat – Dancing Naked in the Moonlight

Lockdown is a bit of a shit! Yes, here we are in Level 4 Lockdown again. Only allowed out for essentials like food and exercise. I did my Saturday, 4 km run today right down the middle of the street because the cars are were completely missing. The covid plague is running wild throughout New Zealand. Can we stop it like we did the last time? New Zealand has done well so far with 5 deaths per million of population compared to the likes of the US and the UK with their 1,900 deaths per million. And our unemployment rate is only 4%. Still, all of that is not good enough for some folk who have been marching in protest against the lockdown. I have to admit that the prospect of hundreds of disease ridden people running amuck in the community is somewhat unsettling. Being old and frail, Gallagher and I have been vaccinated already. While some are lining up for the jab, others are antivaxxers, busily spreading conspiracy theories inspired by Donald Trump.

These three shags down at the boat club can’t decide what to do. Should they stay on the dock or jump into the cold water for the chance of a fresh fish. I feel a bit the same way. This lockdown business gives one time to ponder the great decisions in life. I will turn 76 in just 10 days. My time is running out. Soon I will be but a bitter, distant memory. OMG I might only have another 24 years left! What if I don’t finish the ESPcat (Electric Solar Powered Catamaran) project? Should I finish my book? Maybe a tattoo! I’ve never dropped acid or danced naked in the moonlight. So much to do and so little time.

I’m not really going to do the naked thing but I have been giving serious consideration to purchasing a pair of brand new Yamaha 9.9hp, 4 stroke outboards. I could retire the two old 8 hp motors (one 4 stroke and one 2 stroke) that she now struggles around on. At around $NZ 11,000 those two new motors would make Borderline a reliable boat I could thoroughly enjoy in the sunset of my life. It would be money well spent. Or would it?

Buying those new gasoline outboards could mean the end of the solar powered dream. Solar electric power will cost $NZ 30,000. Call it 3 times as much as the 9.9hp gasoline alternative. Decisions, decisions. I really can’t afford $30,000. Maybe I should sell a share in the boat but with those old motors, she isn’t particularly saleable. I have a bit of time to think about things. Thanks to the plague, I can’t purchase anything, even the 9.9hp Yamahas. It’s too damned cold to go out to the boat and there aren’t even any fish coming up the Whitford creek. I am left with nothing but decisions.

Here are four options I am considering, along with the option of doing nothing at all. There are, of course, many other electric outboards but they are all hugely expensive. These are my picks:

1 – Yamaha 9.9hp gasoline 2 – Eclass 10kW electric 3 – EZoutboard 10kW electric 4 – DIY 10kW outboard

On the left above is the Yamaha 9.9hp high thrust outboard.(1) The 9.9 is reliable and performs well pushing a heavy load. I already have one 8hp high trust Yamaha so I know high thrust Yamahas run well. The high thrust versions swing a huge 11 3/4″ x 5 3/4″ propeller designed to push heavy loads at moderate speed.

Next is the Eclass 10kW electric outboard made in Australia.(2) The electric motor is salt water cooled. At $NZ 14,526 + shipping for two, they are a bit on the pricy side. They make a 6kW version that costs a bit less but might not be powerful enough.

To the right is the EZoutboard 10.5kW electric outboard made in China.(3) The problem with dealing with China is that there is no law in China. It’s like the wild west. You do business at your own peril. The EZoutboard costs $NZ11,085 + shipping for a pair. Shipping from China right now is a big unknown. On the other hand, I really like the EZoutboard because it cools the electric motor with a heat exchanger rather than with salt water. I have asked so many questions about the EZoutboard that the manufacturer is no longer returning my e-mails! Who can blame them.

Finally there is the DIY option.(4) I know, this is probably crazy but if I choose this option I would get to select my electric motor and propeller. Motor and drive electronics for the pair would cost $NZ 5,123 + shipping from Australia. A pair of new outboards to be electrified would cost $NZ 5,200 for a total of $NZ 10, 323 + electric motor shipping.

And let’s not forget the batteries. The electric outboard companies charge 3 prices for the batteries so I will have to supply them myself. Battery prices are dropping every day so I would wait for the last moment to purchase them. If I had to purchase today, I would purchase 48v 13s3p e-cycle batteries, quantity 120 at a cost of $NZ 4,971. I would mount a pair of these batteries in a steel tool box. Sixty tool boxes would cost $NZ 1,140 for a total battery cost of $NZ6,111.

The idea of having 2 sets of 30 steel boxes is for cooling and fire protection. I should note that the advertisement above for the 48v battery appeared in Aliexpress without the red toolbox. The battery advertisement claims that the battery pack is rated at 36 Ah. This rating is complete bullshit! A 13S3P battery pack has 13 cells in series for 48V and 3 groups of 13 in parallel. If the battery pack had a rating of 36 Ah, each cell would have to produce 12 Ah. The actual capacity of 18650 cells varies between 1.8 Ah and 3.5 Ah. So the real capacity of this battery pack is 1.8 x 3 or 5.4 Ah. Each red toolbox has 2 battery packs for 10.8 Ah. Each group of 60 battery packs would produce 60 x 5.4 = 324 Ah. That is 48 x 324 = 15,552 Ah. Only 85% of that power is actually usable so the usable power is 13,219 Wh per engine. Our electric outboards would run for 1.3 hours at 10 kW or 2.6 hours at 6kw. That is assuming that the sun is not shining at all.

I am guessing that the each half of the 4 kW solar array will put out about 1 kW for 8 hours in the summer. That means it would take 1.7 days to charge a completely flat battery. For the kind of boating I do, I expect the battery to never go flat. If it does, I just wait for a bit of sun and I am off again.

Solar cells now cost one NZ dollar per watt so the 4 kW array I have in mind will cost $NZ4,000. So the grand total for solar + battery + electric outboard = 4,000 + 6,111 + 11,000 = $NZ 21,000. I have left out lots of little bits and pieces so call it $30,000 to be realistic. Say it fast and is sounds like nothing at all. Somehow it all sounds to me as crazy as dancing naked in the moonlight.


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