Hi all,

We managed to test the electric outboard on a dinghy the other day and
on speed 3 (of 5) got over 2 hours out of a 60Ah 12V 'mobility
scooter' battery. With the outboard on full speed the current is
supposed to be ~30A.

The thing is that whilst the battery is only 60Ah it's f'in heavy
(17kgs), especially when trying to load / unload from a small boat.

So, rather than going to an equally heavy 4/ 2.5hp outboard motor, I
have been considering the use of LiFePo4 batteries for those
'pottering about' days.

Now, the Lead acid battery should only really be discharged to 50% so
my ~60Ah battery is really only 30Ah whereas a 40Ah Lithium can be
discharged more deeply (without harming the total cycle count) and so
much nearer the 40 Ah capacity. Even if it's only 30Ah it would match
the capacity of the LA but be less than 1/3rd of the weight. The other
pros for the Lithium battery is the theoretical max cycles (2-3x that
of the LA) and a faster recharge time (3-4 hours). A con would be the
price but not by as much as I first imagined (~£200 for the LA v £350
for the Lithium).

So, I was just wondering if anyone here had any real world usage
experience of this sort of size Lithium battery please and especially
when used as a replacement to a lead acid. Golf trolley or mobility
scooter perhaps?

Cheers, T i m

On 11-Sep-16 4:06 PM, T i m wrote:
Hi all,

We managed to test the electric outboard on a dinghy the other day and
on speed 3 (of 5) got over 2 hours out of a 60Ah 12V 'mobility
scooter' battery. With the outboard on full speed the current is
supposed to be ~30A.

The thing is that whilst the battery is only 60Ah it's f'in heavy
(17kgs), especially when trying to load / unload from a small boat.

So, rather than going to an equally heavy 4/ 2.5hp outboard motor, I
have been considering the use of LiFePo4 batteries for those
'pottering about' days.

Now, the Lead acid battery should only really be discharged to 50% so
my ~60Ah battery is really only 30Ah whereas a 40Ah Lithium can be
discharged more deeply (without harming the total cycle count) and so
much nearer the 40 Ah capacity. Even if it's only 30Ah it would match
the capacity of the LA but be less than 1/3rd of the weight. The other
pros for the Lithium battery is the theoretical max cycles (2-3x that
of the LA) and a faster recharge time (3-4 hours). A con would be the
price but not by as much as I first imagined (~£200 for the LA v £350
for the Lithium).

So, I was just wondering if anyone here had any real world usage
experience of this sort of size Lithium battery please and especially
when used as a replacement to a lead acid. Golf trolley or mobility
scooter perhaps?

Cheers, T i m


Sorry to go off at a tangent, but £200 for a lead acid battery?!

http://www.halfords.com/camping-leis...-battery-70-ah

That's a 70 Ah deep cycle battery. It weighs the same as your present
one, and costs £65. It's still f'ing heavy though.

Could you get two smaller ones and link them in parallel? Each one would
then be a bit more manageable.

In message , GB
writes
Sorry to go off at a tangent, but £200 for a lead acid battery?!

http://www.halfords.com/camping-leis.../electrical-po
wer/halfords-leisure-battery-70-ah

That's a 70 Ah deep cycle battery. It weighs the same as your present
one, and costs £65. It's still f'ing heavy though.

Could you get two smaller ones and link them in parallel? Each one
would then be a bit more manageable.

The Halfords one is not a sealed gel-type.

We use 2 car batteries with a 1,2 or both switch in our boat, but I
wouldn't want any chance of acid spillage in a boat small enough to use
an electric outboard.
--
Bill

On 11/09/2016 16:29, GB wrote:

Sorry to go off at a tangent, but £200 for a lead acid battery?!

http://www.halfords.com/camping-leis...-battery-70-ah

Apples and oranges.
No way is that a proper deep cycle battery. And it isn't AGM, nor is it
listed as spill-proof.
Regulations for some types of craft can be quite strict, non AGM/gel may
not even be allowed.

That's a 70 Ah deep cycle battery. It weighs the same as your present
one, and costs £65. It's still f'ing heavy though.

Could you get two smaller ones and link them in parallel? Each one would
then be a bit more manageable.

That may be a good idea, though it does then mean charging and looking
after two batteries instead of just one. Or four instead of two

On Sun, 11 Sep 2016 16:29:48 +0100, GB
wrote:

On 11-Sep-16 4:06 PM, T i m wrote:
Hi all,

We managed to test the electric outboard on a dinghy the other day and
on speed 3 (of 5) got over 2 hours out of a 60Ah 12V 'mobility
scooter' battery. With the outboard on full speed the current is
supposed to be ~30A.

The thing is that whilst the battery is only 60Ah it's f'in heavy
(17kgs), especially when trying to load / unload from a small boat.

So, rather than going to an equally heavy 4/ 2.5hp outboard motor, I
have been considering the use of LiFePo4 batteries for those
'pottering about' days.

Now, the Lead acid battery should only really be discharged to 50% so
my ~60Ah battery is really only 30Ah whereas a 40Ah Lithium can be
discharged more deeply (without harming the total cycle count) and so
much nearer the 40 Ah capacity. Even if it's only 30Ah it would match
the capacity of the LA but be less than 1/3rd of the weight. The other
pros for the Lithium battery is the theoretical max cycles (2-3x that
of the LA) and a faster recharge time (3-4 hours). A con would be the
price but not by as much as I first imagined (~£200 for the LA v £350
for the Lithium).

So, I was just wondering if anyone here had any real world usage
experience of this sort of size Lithium battery please and especially
when used as a replacement to a lead acid. Golf trolley or mobility
scooter perhaps?

Cheers, T i m


Sorry to go off at a tangent, but £200 for a lead acid battery?!

Apparently (average/ round figures) if you had bought it new. ;-)

http://www.phillipsmobility.co.uk/mk...60ah-576-p.asp
http://www.discountscooters.co.uk/60ah-mk-gel-battery
https://www.amazon.co.uk/Mobility-Sm.../dp/B009P4XGQC

http://www.halfords.com/camping-leis...-battery-70-ah

That's a 70 Ah deep cycle battery. It weighs the same as your present
one, and costs £65. It's still f'ing heavy though.

Apples and pears though mate. The one you show is a 'wet / flooded'
battery and the one I have is a gel. Also there is often a difference
between a battery marketed for 'leisure' use and one for
semi-traction.

I would put them as:

SLI. High cranking current but pretty intolerant to sustained high
currents or deep discharges (very thin plates).

Leisure. Don't like high current loads (especially engine starting)
but can be deep(er) discharged with less risk of capacity loss than an
SLI battery.

Semi Traction. Don't like very high current loads (engine starting)
but can sustain moderate high current loads and fairly high depths of
discharge with no cycle loss.

Full traction. As above but will sustain even higher continuous loads
and depths of discharge (tubular plates forklift / EV etc).

And then you get things like 'Marine' which are a like a SLI / Leisure
battery hybrid. ;-)

Or something like that anyway. ;-)

Could you get two smaller ones and link them in parallel? Each one would
then be a bit more manageable.

Not sure I would want to run them in parallel but could use them
individually, one out and one back (as I was thinking of doing with 2
lithium batteries as the voltage cutoff is even more severe than with
lead acid or any other (non Lithium) chemistry actually).

However, when you push a battery harder the capacity also drops so I'd
probably get less out of two 30Ah batteries than one 60Ah one (at that
sort of loading).

Cheers, T i m

On Sun, 11 Sep 2016 17:02:48 +0100, Lee
wrote:

On 11/09/2016 16:29, GB wrote:

Sorry to go off at a tangent, but £200 for a lead acid battery?!

http://www.halfords.com/camping-leis...-battery-70-ah

Apples and oranges.

Doh, I said 'apples and pears'. ;-)

No way is that a proper deep cycle battery. And it isn't AGM, nor is it
listed as spill-proof.

But apart from that ... ;-)

Regulations for some types of craft can be quite strict, non AGM/gel may
not even be allowed.

Good point, but I don't think it applies (in this instance) to the
size of 'portable' craft I happen to be using here.

That's a 70 Ah deep cycle battery. It weighs the same as your present
one, and costs £65. It's still f'ing heavy though.

Could you get two smaller ones and link them in parallel? Each one would
then be a bit more manageable.

That may be a good idea, though it does then mean charging and looking
after two batteries instead of just one. Or four instead of two

Just for the S&G's I put the depleted battery on my little Optimate
charger and it took a good few days (at 800mA) to charge the battery
fully again. ;-)

I think there is an advantage re charging a (LA?) battery slowly, if
you are looking for as high a capacity as possible (finer grains but
less surface area for higher current or summat).

I am also keen to try the electric outboard on our 16' Canadian canoe
and again two LiFePo4 batteries could give us a reasonable range at a
reasonable speed and with the knowledge that if we change the first
battery over and turn round, we should get back ok again on the second
(wind and current allowing etc). Plus we also still have the oars /
paddles. ;-)

Cheers, T i m

On 11/09/2016 17:19, T i m wrote:
On Sun, 11 Sep 2016 17:02:48 +0100, Lee
wrote:

Regulations for some types of craft can be quite strict, non AGM/gel may
not even be allowed.

Good point, but I don't think it applies (in this instance) to the
size of 'portable' craft I happen to be using here.

Hehe fairy snuff



Just for the S&G's I put the depleted battery on my little Optimate
charger and it took a good few days (at 800mA) to charge the battery
fully again. ;-)

I think there is an advantage re charging a (LA?) battery slowly, if
you are looking for as high a capacity as possible (finer grains but
less surface area for higher current or summat).

That's certainly the conventional wisdom, though I don't know how it
stacks up in proper tests.

Is it appropriate to post http://www.batteryfaq.org/ again?


I am also keen to try the electric outboard on our 16' Canadian canoe
and again two LiFePo4 batteries could give us a reasonable range at a
reasonable speed and with the knowledge that if we change the first
battery over and turn round, we should get back ok again on the second
(wind and current allowing etc). Plus we also still have the oars /
paddles. ;-)

So up the creek *with* a paddle lol

On Sun, 11 Sep 2016 16:51:13 +0100, Bill wrote:

snip

We use 2 car batteries with a 1,2 or both switch in our boat,

Which is a good / tested plan, especially when you might be 'out on
the ocean waves'. ;-)

but I
wouldn't want any chance of acid spillage in a boat small enough to use
an electric outboard.

I think some people do use the bigger and salt-water versions of these
'Trolling motors' (as opposed to 'real' electric outboards that are
appearing now [1]) as aux or berthing propulsion on their bigger
boats.

It was just really nice to be pootling along (speed 3 equals a casual
walking pace on the towpath) in near silence and to be able to talk to
your crew and hear all the nature sounds around you.

My favourite sound is that of the wavelets lapping underneath the bow
as you also get when sailing (our next use / test of the boat).

Cheers, T i m

[1] We have the M12:
https://www.yamaha-motor.eu/uk/produ...turestechspecs

https://www.youtube.com/watch?v=lazES4NaQ2Y

(It's neither me nor my boat and I wouldn't set the motor at that
angle nor travel with the rowlocks mounted. ;-)

You then go to something like this (as electric version of a small
self-contained (integral fuel tank) IC outboard):
https://www.youtube.com/watch?v=k2psNmnACpY
Typical German efficiency and design. ;-)

Then this:
https://www.youtube.com/watch?v=CQd-2pKWiE0

To this (and beyond no doubt): ;-)
https://www.youtube.com/watch?v=CIJ8e56eEwM

On Sun, 11 Sep 2016 17:45:40 +0100, Lee
wrote:

snip

I think there is an advantage re charging a (LA?) battery slowly, if
you are looking for as high a capacity as possible (finer grains but
less surface area for higher current or summat).

That's certainly the conventional wisdom, though I don't know how it
stacks up in proper tests.

Ok and nor me. It sorta makes sense though ... crystal size V surface
area etc.

Is it appropriate to post http://www.batteryfaq.org/ again?

I don't you can post something like that too often.


I am also keen to try the electric outboard on our 16' Canadian canoe
and again two LiFePo4 batteries could give us a reasonable range at a
reasonable speed and with the knowledge that if we change the first
battery over and turn round, we should get back ok again on the second
(wind and current allowing etc). Plus we also still have the oars /
paddles. ;-)

So up the creek *with* a paddle lol

Better to be safe than stranded, even up a inshore waterway. ;-)

I have an outstanding question with the river authority people re
licence fees and what constitutes 'powered' craft?

Like, I know anything powered by a petrol or diesel engine would be
'Powered' by their terms ... and something paddled, rowed or peddled
whilst also 'powered' is only done so by 'human power'. Similar with
something pulled by a horse then I'm guessing?

Then you have a sailing boat ... that is being powered by the elements
but then what of something *mechanically* powered using a onboard
windmill connected to a paddle wheel or propeller? Then what of solar
electric? It's not using fossil fuels and is also being powered by the
elements?

At least the body that cover the licensing on the Norfolk (and
Suffolk) Broads give a 30% discount for anything electric powered but
why not free like they do with road tax and electric cars as they are
both equally making use of the infrastructure?

Cheers, T i m

On 11/09/2016 18:29, T i m wrote:

At least the body that cover the licensing on the Norfolk (and
Suffolk) Broads give a 30% discount for anything electric powered but
why not free like they do with road tax and electric cars as they are
both equally making use of the infrastructure?

Because it's assumed that people who want to use a craft in inland
waters are (mostly) well-off and thus a soft target?
Anything to do with water craft seems to be an excuse to charge
disproportionately...

On 11-Sep-16 4:51 PM, Bill wrote:
In message , GB
writes
Sorry to go off at a tangent, but £200 for a lead acid battery?!

http://www.halfords.com/camping-leis.../electrical-po
wer/halfords-leisure-battery-70-ah

That's a 70 Ah deep cycle battery. It weighs the same as your present
one, and costs £65. It's still f'ing heavy though.

Could you get two smaller ones and link them in parallel? Each one
would then be a bit more manageable.

The Halfords one is not a sealed gel-type.

We use 2 car batteries with a 1,2 or both switch in our boat, but I
wouldn't want any chance of acid spillage in a boat small enough to use
an electric outboard.

Yes, I suppose that sealed gel is a really really big advantage for that
purpose.

Does the gel really triple the cost?

On 11-Sep-16 5:07 PM, T i m wrote:
On Sun, 11 Sep 2016 16:29:48 +0100, GB
wrote:

On 11-Sep-16 4:06 PM, T i m wrote:
Hi all,

We managed to test the electric outboard on a dinghy the other day and
on speed 3 (of 5) got over 2 hours out of a 60Ah 12V 'mobility
scooter' battery. With the outboard on full speed the current is
supposed to be ~30A.

The thing is that whilst the battery is only 60Ah it's f'in heavy
(17kgs), especially when trying to load / unload from a small boat.

So, rather than going to an equally heavy 4/ 2.5hp outboard motor, I
have been considering the use of LiFePo4 batteries for those
'pottering about' days.

Now, the Lead acid battery should only really be discharged to 50% so
my ~60Ah battery is really only 30Ah whereas a 40Ah Lithium can be
discharged more deeply (without harming the total cycle count) and so
much nearer the 40 Ah capacity. Even if it's only 30Ah it would match
the capacity of the LA but be less than 1/3rd of the weight. The other
pros for the Lithium battery is the theoretical max cycles (2-3x that
of the LA) and a faster recharge time (3-4 hours). A con would be the
price but not by as much as I first imagined (~£200 for the LA v £350
for the Lithium).

So, I was just wondering if anyone here had any real world usage
experience of this sort of size Lithium battery please and especially
when used as a replacement to a lead acid. Golf trolley or mobility
scooter perhaps?

Cheers, T i m


Sorry to go off at a tangent, but £200 for a lead acid battery?!

Apparently (average/ round figures) if you had bought it new. ;-)

http://www.phillipsmobility.co.uk/mk...60ah-576-p.asp
http://www.discountscooters.co.uk/60ah-mk-gel-battery
https://www.amazon.co.uk/Mobility-Sm.../dp/B009P4XGQC

http://www.halfords.com/camping-leis...-battery-70-ah

That's a 70 Ah deep cycle battery. It weighs the same as your present
one, and costs £65. It's still f'ing heavy though.

Apples and pears though mate. The one you show is a 'wet / flooded'
battery and the one I have is a gel. Also there is often a difference
between a battery marketed for 'leisure' use and one for
semi-traction.

I would put them as:

SLI. High cranking current but pretty intolerant to sustained high
currents or deep discharges (very thin plates).

Leisure. Don't like high current loads (especially engine starting)
but can be deep(er) discharged with less risk of capacity loss than an
SLI battery.

Semi Traction. Don't like very high current loads (engine starting)
but can sustain moderate high current loads and fairly high depths of
discharge with no cycle loss.

Full traction. As above but will sustain even higher continuous loads
and depths of discharge (tubular plates forklift / EV etc).

And then you get things like 'Marine' which are a like a SLI / Leisure
battery hybrid. ;-)

Or something like that anyway. ;-)

Could you get two smaller ones and link them in parallel? Each one would
then be a bit more manageable.

Not sure I would want to run them in parallel but could use them
individually, one out and one back (as I was thinking of doing with 2
lithium batteries as the voltage cutoff is even more severe than with
lead acid or any other (non Lithium) chemistry actually).

However, when you push a battery harder the capacity also drops so I'd
probably get less out of two 30Ah batteries than one 60Ah one (at that
sort of loading).

Cheers, T i m


Thanks for explaining it all so patiently. I was genuinely surprised at
the cost difference.

I suspect that at least part of the cost difference is down to economies
of scale, as far more wet batteries are sold than gel. Similarly with
the different types. I wonder whether that explains it all, or is there
a bigger dealer margin for all things disability related?

On Sun, 11 Sep 2016 21:40:05 +0100, Lee
wrote:

On 11/09/2016 18:29, T i m wrote:

At least the body that cover the licensing on the Norfolk (and
Suffolk) Broads give a 30% discount for anything electric powered but
why not free like they do with road tax and electric cars as they are
both equally making use of the infrastructure?

Because it's assumed that people who want to use a craft in inland
waters are (mostly) well-off and thus a soft target?

Probably.

Anything to do with water craft seems to be an excuse to charge
disproportionately...


True. ;-(

My Dad used to say that 'a boat was a hole in the water into which you
could pour money ... ". ;-)

Cheers, T i m

On Sun, 11 Sep 2016 22:14:49 +0100, GB
wrote:

snip

Or something like that anyway. ;-)

snip

Thanks for explaining it all so patiently.

You are more than welcome. It was only my rough understanding of it
all. ;-)

I was genuinely surprised at
the cost difference.

So was I (as I bought the battery second had for a fraction of that).
I only found the real / current cost when Googling earlier as I was
trying to get insurance for the boat and either the electric outboard
and batteries ... or the boat plus 4/ outboard.

I suspect that at least part of the cost difference is down to economies
of scale, as far more wet batteries are sold than gel.

You could be right. That said, there are quite a few gel / sealed
batteries in use out there, from burglar alarms to golf buggies,
UPS's, motorbikes and mobility scooters etc.

Similarly with
the different types. I wonder whether that explains it all, or is there
a bigger dealer margin for all things disability related?

Again, as Lee mentioned elsewhere re things 'boating', I'm sure there
is some of that as well.

Cheers, T i m

In message , T i m
writes
You then go to something like this (as electric version of a small
self-contained (integral fuel tank) IC outboard):
https://www.youtube.com/watch?v=k2psNmnACpY
Typical German efficiency and design. ;-)

Errrm, with all the weight, battery, driver, motor and water in the
bottom of he boat at the stern, about half the hull length is out of the
water. So the hull speed will be very low, and energy will be going into
generating the stern wave rather than moving the boat.

But I've always fancied an electric outboard or a small inboard with
battery charged from solar cells. Not sure whether it's feasible,
though.

I'm not sure our old Seagull is actually legal anywhere anymore.

--
Bill

Putting batteries in parallel like this if not actually charging or being
used does tend to shorten their charged time I have found.
I wonder what special features his 200 quid battery has over a normal one?
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"GB" wrote in message
...
On 11-Sep-16 4:06 PM, T i m wrote:
Hi all,

We managed to test the electric outboard on a dinghy the other day and
on speed 3 (of 5) got over 2 hours out of a 60Ah 12V 'mobility
scooter' battery. With the outboard on full speed the current is
supposed to be ~30A.

The thing is that whilst the battery is only 60Ah it's f'in heavy
(17kgs), especially when trying to load / unload from a small boat.

So, rather than going to an equally heavy 4/ 2.5hp outboard motor, I
have been considering the use of LiFePo4 batteries for those
'pottering about' days.

Now, the Lead acid battery should only really be discharged to 50% so
my ~60Ah battery is really only 30Ah whereas a 40Ah Lithium can be
discharged more deeply (without harming the total cycle count) and so
much nearer the 40 Ah capacity. Even if it's only 30Ah it would match
the capacity of the LA but be less than 1/3rd of the weight. The other
pros for the Lithium battery is the theoretical max cycles (2-3x that
of the LA) and a faster recharge time (3-4 hours). A con would be the
price but not by as much as I first imagined (~£200 for the LA v £350
for the Lithium).

So, I was just wondering if anyone here had any real world usage
experience of this sort of size Lithium battery please and especially
when used as a replacement to a lead acid. Golf trolley or mobility
scooter perhaps?

Cheers, T i m


Sorry to go off at a tangent, but £200 for a lead acid battery?!

http://www.halfords.com/camping-leis...-battery-70-ah

That's a 70 Ah deep cycle battery. It weighs the same as your present one,
and costs £65. It's still f'ing heavy though.

Could you get two smaller ones and link them in parallel? Each one would
then be a bit more manageable.

I thought that these days most of these batteries claimed to be anti spill,
assuming you make sure everything is secured. Most venting is done in a way
that won't let the acid out. There can be, however a very naff smell if its
charged in an enclosed area.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Bill" wrote in message
...
In message , GB
writes
Sorry to go off at a tangent, but £200 for a lead acid battery?!

http://www.halfords.com/camping-leis.../electrical-po
wer/halfords-leisure-battery-70-ah

That's a 70 Ah deep cycle battery. It weighs the same as your present one,
and costs £65. It's still f'ing heavy though.

Could you get two smaller ones and link them in parallel? Each one would
then be a bit more manageable.

The Halfords one is not a sealed gel-type.

We use 2 car batteries with a 1,2 or both switch in our boat, but I
wouldn't want any chance of acid spillage in a boat small enough to use an
electric outboard.
--
Bill

Of course if you use it on a proper like sailing bot, stick the battery down
the keel as ballast grin.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"T i m" wrote in message
...
On Sun, 11 Sep 2016 16:51:13 +0100, Bill wrote:

snip

We use 2 car batteries with a 1,2 or both switch in our boat,

Which is a good / tested plan, especially when you might be 'out on
the ocean waves'. ;-)

but I
wouldn't want any chance of acid spillage in a boat small enough to use
an electric outboard.

I think some people do use the bigger and salt-water versions of these
'Trolling motors' (as opposed to 'real' electric outboards that are
appearing now [1]) as aux or berthing propulsion on their bigger
boats.

It was just really nice to be pootling along (speed 3 equals a casual
walking pace on the towpath) in near silence and to be able to talk to
your crew and hear all the nature sounds around you.

My favourite sound is that of the wavelets lapping underneath the bow
as you also get when sailing (our next use / test of the boat).

Cheers, T i m

[1] We have the M12:
https://www.yamaha-motor.eu/uk/produ...turestechspecs

https://www.youtube.com/watch?v=lazES4NaQ2Y

(It's neither me nor my boat and I wouldn't set the motor at that
angle nor travel with the rowlocks mounted. ;-)

You then go to something like this (as electric version of a small
self-contained (integral fuel tank) IC outboard):
https://www.youtube.com/watch?v=k2psNmnACpY
Typical German efficiency and design. ;-)

Then this:
https://www.youtube.com/watch?v=CQd-2pKWiE0

To this (and beyond no doubt): ;-)
https://www.youtube.com/watch?v=CIJ8e56eEwM

On Mon, 12 Sep 2016 00:40:28 +0100, Bill wrote:

In message , T i m
writes
You then go to something like this (as electric version of a small
self-contained (integral fuel tank) IC outboard):
https://www.youtube.com/watch?v=k2psNmnACpY
Typical German efficiency and design. ;-)

Errrm, with all the weight, battery, driver, motor and water

I'm not sure that last bit is right Bill. ;-)

in the
bottom of he boat at the stern, about half the hull length is out of the
water.

Horrible, but if you are talking about the video linked above it's an
inflatable and I'm not sure trim makes any difference on them. ;-)

However, Dad (an ex Merchant marinier) impressed on me the need for
good boat trim at a very early age (especially when rowing).

So the hull speed will be very low, and energy will be going into
generating the stern wave rather than moving the boat.

Quite.

You can always tell a good dinghy sailor when you see then move
forward when on a run to live the stern out of the water if they can.

But I've always fancied an electric outboard or a small inboard with
battery charged from solar cells. Not sure whether it's feasible,
though.

I'm drying to keep enhance the electric propulsion theme as it makes
good sense where low levels of acceleration and low peak / near
constant loads are in play (so unlike an EV then). I think the ideal
utilisation of that would be an electric narrow boat where you require
ballast anyway (so cheap lead acid batteries are still viable), the
batteries rarely suffer much in the way of mechanical shock or
vibration and there is a fairly large roof, ripe for flexible solar
panels. A heavy narrow boat also makes for a good stable platform for
a reasonable size wind turbine when moored (or traveling down wind).
;-). [1]

I'm not sure our old Seagull is actually legal anywhere anymore.

I think the use of 2/'s are still allowed on many rivers and canals
(even them running at 10:1) and of course the sea but I'm sure they
are being banned on many reservoirs (if IC engines were ever allowed
in the first place) or places with sensitive environmental interest. I
also understand it's illegal (over here) to sell new 2/'s now days?

Funny you mention Seagulls ... I think I have spent more hours in
front of a BS (mostly 40+ and 40 Featherweight than the Silver
Century) than any other make or model of outboard and my first formal
'fitter' role was to fit the long range tank and recoil starter
upgrades for Dad on any new BS we bought.

We also recently sold a nearly new 40+ that had been hanging in Dads
workshop for probably 20 years to a mate who had his BS nicked out of
his shed. And another mate has one in his loft he said he would give
to me the next time I see him. ;-)

However, as 'tough reliable' as the BS's were, I don't think there is
much that would beat the little Yamaha 2hp 2/ for lightness and
efficiency.

Cheers, T i m

[1] We hired an electric dayboat / launch from somewhere (can't
remember now) and it was quite eerie moving along at the speed limit
in near silence ... and hearing all those on motor boats shouting at
each other just to communicate. ;-)

On Mon, 12 Sep 2016 08:41:49 +0100, "Brian Gaff"
wrote:

Of course if you use it on a proper like sailing bot, stick the battery down
the keel as ballast grin.

Funnily enough, that's exactly what we did when we took the dinghy out
the other day. We aren't sailing but I placed the battery under the
centre thwart, up against the dagger board casing because there were
three of us anyway so I didn't need the battery to act as trim
ballast. ;-)

Cheers, T i m

On Mon, 12 Sep 2016 08:40:11 +0100, "Brian Gaff"
wrote:

I thought that these days most of these batteries claimed to be anti spill,
assuming you make sure everything is secured.

I think you are right but you still sometimes have to move them in and
out the boat.

Most venting is done in a way
that won't let the acid out.

I think they use a 'recombination' vent cap in each of the cells that
help keep the electrolyte levels correct but because the battery still
needs to vent, they often still have to have something to allow that.

There can be, however a very naff smell if its
charged in an enclosed area.

And potentially very explosive. Whilst 'I love the smell of hydrogen
in the morning' ... I'm also aware of good ventilation and keeping
sparks to a minimum. ;-)

Cheers, T i m

On Mon, 12 Sep 2016 08:38:01 +0100, "Brian Gaff"
wrote:

Putting batteries in parallel like this if not actually charging or being
used does tend to shorten their charged time I have found.

Agreed. I generally don't do that at all if I can avoid it (and I
generally can). ;-)

I wonder what special features his 200 quid battery has over a normal one?

I don't think it's 'this' battery as such (and you many not have meant
that one specifically) but I believe 'Gel, AGM, Calcium, Semi
Traction' and just 'good quality' all play a part.

And the fact that I bought this particular battery second hand, many
years ago and it can still run three of us up and down the river for
over two hours with little use (but regular charges) in between
probably reflects why it is 'different from many other offerings?

In it's class I have no idea how good or bad it is.

Cheers, T i m

On 12/09/2016 09:04, T i m wrote:
A heavy narrow boat also makes for a good stable platform for
a reasonable size wind turbine when moored (or traveling down wind).

A wind turbine will surprisingly still work upwind. You're extracting
energy from the movement of the wind against the water.

Whether the efficiency is good enough that it's worth doing is another
matter.

Andy

On Tue, 13 Sep 2016 21:53:42 +0100, Vir Campestris
wrote:

On 12/09/2016 09:04, T i m wrote:
A heavy narrow boat also makes for a good stable platform for
a reasonable size wind turbine when moored (or traveling down wind).

A wind turbine will surprisingly still work upwind.

I would have thought it would work 'better' (as an electricity
generator)?

You're extracting
energy from the movement of the wind against the water.

But in so doing reducing the efficiency of the transmission system
with the turbine acting as an air brake.

Whether the efficiency is good enough that it's worth doing is another
matter.

Quite, that's why I only suggested it's use downwind (where it acting
like a sail could only add to the overall efficiency). ;-)

Cheers, T i m

On 13/09/16 21:53, Vir Campestris wrote:
On 12/09/2016 09:04, T i m wrote:
A heavy narrow boat also makes for a good stable platform for
a reasonable size wind turbine when moored (or traveling down wind).

A wind turbine will surprisingly still work upwind. You're extracting
energy from the movement of the wind against the water.

Whether the efficiency is good enough that it's worth doing is another
matter.

Andy
IN fact a wind turbine can allow a boat to sail faster downwind than the
wind is blowing..


--
"If you dont read the news paper, you are un-informed. If you read the
news paper, you are mis-informed."

Mark Twain

On 14/09/2016 00:42, The Natural Philosopher wrote:
IN fact a wind turbine can allow a boat to sail faster downwind than the
wind is blowing..


I'd like a link to that. I've never seen it done in a boat, although on
land it's been done to quite large speed ratios.

Andy

In article ,
T i m wrote:
Now, the Lead acid battery should only really be discharged to 50% so
my ~60Ah battery is really only 30Ah whereas a 40Ah Lithium can be
discharged more deeply (without harming the total cycle count) and so
much nearer the 40 Ah capacity. Even if it's only 30Ah it would match
the capacity of the LA but be less than 1/3rd of the weight. The other
pros for the Lithium battery is the theoretical max cycles (2-3x that
of the LA) and a faster recharge time (3-4 hours). A con would be the
price but not by as much as I first imagined (~£200 for the LA v £350
for the Lithium).

200 quid for a 60 amp deep cycle lead acid? Sounds like the sort of price
a disability shop would charge.

You'd also need to buy a charger for the Lithium?

BTW, I'd also get some advice on just how many cycles you'll get out of
the Lithium at a high discharge rate.

--
*Born free - taxed to death *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Lee wrote:
Apples and oranges.
No way is that a proper deep cycle battery. And it isn't AGM, nor is it
listed as spill-proof.
Regulations for some types of craft can be quite strict, non AGM/gel may
not even be allowed.

I'd have thought if the boat capsized, the battery type might be the least
of your problems. ;-)

--
*Life is hard; then you nap

Dave Plowman London SW
To e-mail, change noise into sound.