Electric sportcruiser

[ontheplane]

I am very sceptical about your 15 mile per kWh figure; in a 100kWh Tesla that would result in a range of 1500 miles; I’ve hypermiled in BEVs and not got near that high efficiency figure you quoted if we are talking about level ground; a gradient is another matter of course, but what comes up must go down and regen isn’t as efficient as not using the energy in the first place. EVs are at optimum efficiency between 20 and 25mph; any lower and you hold onto very little momentum, any higher and you get impacted by drag.

I was talking ONLY about town speed - the minute I hit the larger a roads it goes back to a more normal 5m/KWh kind of figure and then motorway is more 3.5-3.8.

The point I think I was trying to make is that ICE is efficient at motorway speeds but EV's are most efficient at very low speeds.

The point about displacement is if you aren't trying to go over hull speed you can gear a very low powered motor to drive a relatively large boat, especially as you can get a lot of torque from a small electric motor

 

[ontheplane]

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[ontheplane]

Which model is it ?

Kia Soul 64KWh

So looking at the current rate of deterioration, the battery should last 20 years before its down to say 60%

A 35kwh battery would make fantastic home storage unit so there is a really strong usage there for the old battery

 

[Bouba]

Kia Soul 64KWh

So looking at the current rate of deterioration, the battery should last 20 years before its down to say 60%

A 35kwh battery would make fantastic home storage unit so there is a really strong usage there for the old battery

Exactly ….it’s hard to get the message across to the non-ev crowd but the battery should outlast the car and then you are free to do as you please with it…powering a static caravan for example
Mine is a Tesla M3LR

 

[AndrewJ5]

I was talking ONLY about town speed - the minute I hit the larger a roads it goes back to a more normal 5m/KWh kind of figure and then motorway is more 3.5-3.8.

The point I think I was trying to make is that ICE is efficient at motorway speeds but EV's are most efficient at very low speeds.

The point about displacement is if you aren't trying to go over hull speed you can gear a very low powered motor to drive a relatively large boat, especially as you can get a lot of torque from a small electric motor

I did read your original message and to be clear I wasn't trying to be argumentative. I can only imagine it momentarily hits that high figure on the dashboard. My scepticism comes from hypermiling an EV myself, as well as the below article which details a test done whereby they stuck to 19mph in a regular Renault Zoe 50 on a track, added ultra low RR tyres and still didn't get near 15 miles/kWh.

Regular Zoe 50 with standard tyres returned 9.1 miles/kWh, and the ultra low RR tyres returned 10.5 miles/kWh. Given that it sounds like you weren't going for a hypermiling record as the aforementioned were, you can understand my scepticism. I'm all in favour of electrification, I'm not trying to be difficult; I'm actually trying to work out the viability of e-retrofitting boats and the energy required with different boat weights, styles, hull types and length/width ratios. Many of the arguments in this thread, including some of yours support my assessments thus far. I just can't see everyone buying new boats to displace the old ones with say hydrofoils; all that embodied energy and money invested in the existing GRP hulls. Are they all going to run on biodiesel or similar when regulations come in? Or simply run at their hull speed. It is a tricky situation as hydrofoil boats such as Candela's are far more efficient at planing speeds. That said there are many new e-boats being launched that don't come with hydrofoils but most have a high length to width ratio unless they're catamarans.

As has been said, the issue of charging is also going to be tricky; shore power next to each berth is what, 3kW, could be upgraded to 7kW without too much difficulty but beyond that, it gets tricky and expensive and as has been said, significant amounts of power would need to be drawn from the local substation, which would have to be upgraded. A 150kW supercharger would only take 1 boat at at time; you'd need multiple chargers and mooring space for them and still serve a fraction of the boats in the marina. Ribs, small boats, foiling boats and sailing boats would be fine with shorepower most of the time. It's ironic as now that I can probably consider a large used motorboat, I don't want to be using diesel so my options have altered accordingly. The benefits of easier low speed handling, no fumes, far less maintenance and far lower noise levels are compelling.

Indeed, with more people installing renewable power domestically and commercially there is definitely a long life ahead for 2nd life batteries but most EVs aren't at that stage unless they've been totalled and even then they may be repurposed into retrofitting a classic or used car.

Beyond hypermiling: How two Renault Zoes busted range anxiety | Autocar

 

[Rwc13]

Anyone else going to the electric boat show at Lagos this weekend?

 

[AndrewJ5]

Anyone else going to the electric boat show at Lagos this weekend?

Unfortunately not; I noticed it was on due to following Aqua superpower; if you’re going I hope you report back on anything interesting ?

 

[Assassin]

On boats this would be a non- issue

I charge my elec car every day and in 2 years battery SOH is still 100%, I still get the same range, so with the tiny number of cycles on a boat, age would be the only problem - but it will certainly be 20 years of life and then a second use as home storage batteries probably.

So what you are claiming is that in 2 years your battery has suffered no degredation or performance loss, and next can I have your battery as this is unique in having both no cyclic or age related deterioration and it must be the only battery of its type.

 

[AndrewJ5]

So what you are claiming is that in 2 years your battery has suffered no degredation or performance loss, and next can I have your battery as this is unique in having both no cyclic or age related deterioration and it must be the only battery of its type.

Indeed, and second dibs if it doesn’t work out for you ;-) perhaps the percentage reading hasn’t changed but as you say the battery will most certainly have degraded for both the reasons you highlighted. It may not have degraded sufficiently for it to be that noticeable; I have a 7 year old ebike battery and it has lost some state of charge but it’s not that noticeable; perhaps I just run it closer to zero than before

 

[Bouba]

Ok...its very true that the batteries will deteriorate according to an established formula...calendar aging and cyclic degradation.
However...that is an average...on a bell chart there will be outliers that either degrade rapidly or hardly at all. On the Tesla forum there is an expert on batteries (like a Tesla Vas?) who lives in a cold country and his battery doesn’t lose anything.
The other variable is the Battery Management Program that tells you how much charge you can hold and how much range you can go....it sometimes needs recalibration. And then there is the buffer...if it has one..is it at the bottom of the charge (below zero%) or at the top (above 100%)...
All these things are above my education level and please do not quote me or ask questions ??

 

[kashurst]

So what you are claiming is that in 2 years your battery has suffered no degredation or performance loss, and next can I have your battery as this is unique in having both no cyclic or age related deterioration and it must be the only battery of its type.

I had a BMW i3 for 4 years and it had no discernable battery degradation. EV batteries degrade with frequent rapid charging. Most EV owners rarely rapid charge. This year I have done it 6 times so far.

 

[ontheplane]

So what you are claiming is that in 2 years your battery has suffered no degredation or performance loss, and next can I have your battery as this is unique in having both no cyclic or age related deterioration and it must be the only battery of its type.

Go on the EV forums and you will see that there are no recorded cases of Kia Soul or Niro cars 64KWh suffering any degradation. Even the early 30kw cars have very little and some of them are 7 years old.....

So the degradation is currently too small to measure.....

The SOH is still 100%.

From 10% charged to full yesterday took 58KWh (so the same as when new) and am showing 280m range as I did when it was new.....

So yep - 2 years in, that's is what I am saying.....

And no, why would I give you a perfectly good battery lol - when I'm done with it it's going as battery house storage!

 

[Assassin]

And more people knowing more than the leading battery experts.

 

[ontheplane]

I don't know anything other than what I am experiencing in actual real life.

When I got the car a full charge took approx 64kwh of power, it still does.

On a mild spring day the estimated range is 280m as it always was....

So in the real world it appears the battery is as good as it was - if there is any degradation, I can't see it

 

[Bouba]

I don't know anything other than what I am experiencing in actual real life.

When I got the car a full charge took approx 64kwh of power, it still does.

On a mild spring day the estimated range is 280m as it always was....

So in the real world it appears the battery is as good as it was - if there is any degradation, I can't see it

Which battery do you have?

 

[stelican]

Will catarmarans use twice as much power.

 

[ontheplane]

Will catarmarans use twice as much power.

At displacement speeds, length for length, quite a bit less. At planing speeds, not sure

 

[ontheplane]

Which battery do you have?

67kwh battery, 64kwh use able -I think there is a 2kwh buffer at the bottom end and a 1kwh at the top

 

[Bouba]

67kwh battery, 64kwh use able -I think there is a 2kwh buffer at the bottom end and a 1kwh at the top

By which manufacturer and which chemistry?

 

[ontheplane]

Don't know - not taken it out!