Lithium Batteries

[geem]

This is one of my big concerns for next year - we have a good hard pram style dingy that doesn't seem to ship water whatever we do to it but only an electric outboard - wired to a 50AH LifePo4 - cos they're waterproof (in the case this one comes in) and nice and safe - which should give 3-4 hours at 2-3 knots BUT it slows down a lot in to a wind or chop ...

We never go anywhere at less than 12 kts. We are flat out in our hard dinghy at 21kts. At 3.8m long we can carry dive gear, bikes, 4 people or what ever and still stay dry and make good speed. In my experience, you miss out on lots of the pleasures that the Caribbean has to offer without a decent dinghy/engine combo. When we were learning to kite surfing the dinghy was our rescue boat. Try chasing a kitesurfer at 3 kts?

 

[simonfraser]

I thought there were some doubts about LTO under certain conditions but GWL certainly market them as safe as LFP. Although, as you say, they aren't friendly for 12 volt systems and don't have other redeeming features including cost. GWL torture video below.

I totally agree about other fuel sources and it was recently a relief to be able to give up storing petrol aboard when switching to an electric outboard.

excellent video, should have included a lead acid battery in the test too

 

[geem]

excellent video, should have included a lead acid battery in the test too

I find it strange that people are relieved to give up storing petrol. That's what the deck is for. We never keep petrol in a locker. It's lives in 20 litre cans on deck in a purpose made cradle ( a bit of wood wedged between the granny bars with some rope through the handles?). Super safe.
Nobody seems to get upset with gas cookers in their house or gas boilers. Happy to keep their petrol powered car in their garage.
Petrol is an incredible fuel with fantastic energy density. Electric outboards just don't do it for me. Cant wakeboard behind the dinghy?

 

[Trident]

I find it strange that people are relieved to give up storing petrol. That's what the deck is for. We never keep petrol in a locker. It's lives in 20 litre cans on deck in a purpose made cradle ( a bit of wood wedged between the granny bars with some rope through the handles?). Super safe.
Nobody seems to get upset with gas cookers in their house or gas boilers. Happy to keep their petrol powered car in their garage.
Petrol is an incredible fuel with fantastic energy density. Electric outboards just don't do it for me. Cant wakeboard behind the dinghy?

I was very happy to get rid of gas on the boat to go all electric on the galley. I built my boats very "gas safe " and was always pretty relaxed until one evening mentioning how paranoid people were about gas on boats (I appreciate you said house) given that I'd never heard first hand of a gas explosion on a boat. One old guy in the marina replied he'd seen 4 personally , including watching a man blown off the top of his boat in Poole Harbour and land in the water in front of him. Another mentioned having been in two marinas where gas had exploded on board a boat and so on. Even so, my choice to go all electric on the galley was prompted by laziness; not wanting to carry heavy gas cylinders around the South Pacific islands trying to get them filled..

Petrol is as you say safest stored on deck but then jerry cans look so untidy and petrol outboards are so heavy . I managed to find an 8 bhp equivalent electric outboard last night that will probably get 10 knots out of my 22kg dinghy and should last 25 miles at more like 4 knots. I would say easily as good as any petrol outboard, free to recharge from solar and under 20kg. I am very deliberately not going to mention the price otherwise my entire argument will be nullified

 

[geem]

I was very happy to get rid of gas on the boat to go all electric on the galley. I built my boats very "gas safe " and was always pretty relaxed until one evening mentioning how paranoid people were about gas on boats (I appreciate you said house) given that I'd never heard first hand of a gas explosion on a boat. One old guy in the marina replied he'd seen 4 personally , including watching a man blown off the top of his boat in Poole Harbour and land in the water in front of him. Another mentioned having been in two marinas where gas had exploded on board a boat and so on. Even so, my choice to go all electric on the galley was prompted by laziness; not wanting to carry heavy gas cylinders around the South Pacific islands trying to get them filled..

Petrol is as you say safest stored on deck but then jerry cans look so untidy and petrol outboards are so heavy . I managed to find an 8 bhp equivalent electric outboard last night that will probably get 10 knots out of my 22kg dinghy and should last 25 miles at more like 4 knots. I would say easily as good as any petrol outboard, free to recharge from solar and under 20kg. I am very deliberately not going to mention the price otherwise my entire argument will be nullified

We have plenty of friends cruising the South Pacific. It's called cooking gas. Since everybody uses it, it's cheap and available.
We carry several months supply. No hardship in a decent dinghy to take a couple of gas bottles ashore and pick them up the next day every 3 months.
I have also seen gas explosions. The last one was an old French guy in Horta in 2020. Changing his gas bottle whilst smoking. The boat was destroyed. I think he died. Boat was totalled. Stupidity knows no limits.
As to carrying fuel on deck looking ugly, don't get me started on solar arches. If the yacht designers out there saw some of the monstrosities stuck on the back of otherwise good looking boats they would be crying. Some owners must have shares in steel companies. The weight added plus the rib and engine hanging out there dragging the stern down. Horrible mess
There just such a Jen sun Odyssey 49 next to us at the moment. A long row of fuel cans on deck cos Jen put a tiny fuel tank in their long range cruising boat. A massive structure hanging off the back. No bottom paint showing and the hull fully immersed at the stern.

 

[kwb78]

I wasn’t suggesting people should or should not use any particular energy source. My point was more that people tend to underplay or take for granted risks associated with things that are familiar to them, and overplay or pay much more attention to risks from things they don’t know about or are new to them.

There are dangers associated with most power sources, and especially so on boats, but for most of them the risks are factored in to how we use them (eg storing petrol on deck instead of a confined space). That doesn't stop people using them inappropriately occasionally, either through ignorance or complacency, but there is nothing inherently more dangerous with lithium batteries (LiPo aside) over other types assuming they are used properly.

 

[mattonthesea]

Wait until you get to the Caribbean and see if you are still happy with an electric outboard.
The distances between you anchored boat and the dinghy dock can be up to a mile. The water is often choppy and you get regular squalls with heavy rain. When we first came to the Caribbean nearly 20 years ago, we had a small deflatable and a 3.5hp engine. You soon get sick of being soaked when going out to a restaurant in the evening in your finest.
Even worse with 3 or 4 people in the dinghy.
I can't imagine not having a good dinghy and 15hp 2 stroke here.

That's so different from my experience. I anchored up close in most places and rowed ashore. I had a heavy petrol outboard so avoided handling it. I draw 1.5m.

Bequai was an exception! And, of course, this was a decade ago.

M

 

[Kelpie]

Imanaged to find an 8 bhp equivalent electric outboard last night that will probably get 10 knots out of my 22kg dinghy and should last 25 miles at more like 4 knots. I would say easily as good as any petrol outboard, free to recharge from solar and under 20kg. I am very deliberately not going to mention the price otherwise my entire argument will be nullified

Well you've got my attention! Does the 20kg include the battery though?

 

[geem]

I wasn’t suggesting people should or should not use any particular energy source. My point was more that people tend to underplay or take for granted risks associated with things that are familiar to them, and overplay or pay much more attention to risks from things they don’t know about or are new to them.

There are dangers associated with most power sources, and especially so on boats, but for most of them the risks are factored in to how we use them (eg storing petrol on deck instead of a confined space). That doesn't stop people using them inappropriately occasionally, either through ignorance or complacency, but there is nothing inherently more dangerous with lithium batteries (LiPo aside) over other types assuming they are used properly.

That's so different from my experience. I anchored up close in most places and rowed ashore. I had a heavy petrol outboard so avoided handling it. I draw 1.5m.

Bequai was an exception! And, of course, this was a decade ago.

M

We used to anchor close to shore when we had a catamaran. Thought it was a good idea but we now know that the boats that end up on beaches are ones anchored close to shore. Mozzies live close to shore and theft happens close to shore. Loud music comes from the shore.
Lots of anchorages are busy and getting a spot close to shore is not alway possible. By choise these days we anchor further out.
We are currently in Jolly Harbour Antigua. It's a mile to the dinghy dock. There are about 20 boats in the anchorage and not a single small dinghy with small outboard. All the catamarans are close to the beach. If we see anybody rowing here we would comment on it as a rarity.

 

[mattonthesea]

We are currently in Jolly Harbour Antigua. It's a mile to the dinghy dock. There are about 20 boats in the anchorage and not a single small dinghy with small outboard. All the catamarans are close to the beach. If we see anybody rowing here we would comment on it as a rarity.

Yes music is loud but that's just something I tuned out. Bleedin' high speed dinghies tho'! Sail an ocean at 7kts and a harbour at 20kts ?

Yes scarcity; only two of us rowed in Jolly harbour. Took me all of 30s to the dinghy dock. Just seen on satellite that there's a super yacht pontoon there now.

 

[geem]

Yes music is loud but that's just something I tuned out. Bleedin' high speed dinghies tho'! Sail an ocean at 7kts and a harbour at 20kts ?

Yes scarcity; only two of us rowed in Jolly harbour. Took me all of 30s to the dinghy dock. Just seen on satellite that there's a super yacht pontoon there now.

Haha, 5kt speed limit that they seem to be enforcing. Lots of new signs. We make a nice big wake at 5kts?

 

[Trident]

don't get me started on solar arches. If the yacht designers out there saw some of the monstrosities stuck on the back of otherwise good looking boats they would be crying. Some owners must have shares in steel companies. The weight added plus the rib and engine hanging out there dragging the stern down. Horrible mess
There just such a Jen sun Odyssey 49 next to us at the moment. A long row of fuel cans on deck cos Jen put a tiny fuel tank in their long range cruising boat. A massive structure hanging off the back. No bottom paint showing and the hull fully immersed at the stern.

I think only cats can really work with lots of solar - and even then only big cats make it look natural. Our 50 foot barely notices 2kw of solar on the roof

I did recently see an all electric (engines too) 34 foot cat moored next to its diesel sister ship - and with all the lithium batteries and extra solar it sat 6 inches lower than the diesel (and cost £80K more) and had about 4 hours range before the diesel kicked in!

 

[geem]

I think only cats can really work with lots of solar - and even then only big cats make it look natural. Our 50 foot barely notices 2kw of solar on the roof

I did recently see an all electric (engines too) 34 foot cat moored next to its diesel sister ship - and with all the lithium batteries and extra solar it sat 6 inches lower than the diesel (and cost £80K more) and had about 4 hours range before the diesel kicked in!

Yep, big cats make solar look easy. Our friends 56ft cat has it all located on the hard bimini. You don't even know its there. 2kw.
A sweet looking cat, fast, carbon daggerboards, carbon mast, cored hull but a $2 million US build cost in 2000.

 

[DuncanHall]

One final post.

The time taken to do this thread has had an unexpected benefit.

My final solution is to use 3 Foxstar drift 105AH units. Plus a stirling 1260 Battery to battery charger to prevent damaging the alternator, an upgraded 100A Alternator plus appropriate fusing. The choice of 3 units is partially constrained by the sixe of my battery compartment and the desire to remove the risk of a single BMs failure causing issues.

In the course of the discussion the price of the heated fogstar units is fell to £369 each. Whists not quite drop in replacements the price is similar to the Four 110AH AGMs that they replace.

Duncan

 

[Steve_N]

I would get your pre-order in quickly for the Fogstars.
Yesterday morning they were £430 and I was waiting for 'Fogstar Friday' when they usually release a 15% discount code. I 'd left one in my basket from the day before and even received a 'complete your purchase' email including a 15% discount code - but neither this code nor the Fogstar Friday one worked on leisure batteries and they then added a disclaimer to that effect to each battery page - discount codes not applicable to batteries.
Then at around Friday lunchtime all their lithium leisure battery prices fell by around 15%..

I've no idea what's going on - the lower price might even be a mistake - but I suspect that they'll be back up to full price (still a great price though) on Monday.

 

[PaulRainbow]

One final post.

The time taken to do this thread has had an unexpected benefit.

My final solution is to use 3 Foxstar drift 105AH units. Plus a stirling 1260 Battery to battery charger to prevent damaging the alternator, an upgraded 100A Alternator plus appropriate fusing. The choice of 3 units is partially constrained by the sixe of my battery compartment and the desire to remove the risk of a single BMs failure causing issues.

In the course of the discussion the price of the heated fogstar units is fell to £369 each. Whists not quite drop in replacements the price is similar to the Four 110AH AGMs that they replace.

Duncan

I would suggest you look at Victron for the B to B charger, rather than Sterling.

 

[Poey50]

I would suggest you look at Victron for the B to B charger, rather than Sterling.

I agree with Paul. I had a 60 amp Sterling B2B with a 100 amp alternator. Because of the insatiable appetite of the LFP the B2B ran very hot and had to switch itself off to cool down ... over and over again. Also the rule of thumb for alternator capacity to avoid overheating the alternator is 2:1. So that would be a 120 amp alternator to give sufficient headroom for a 60 amp B2B. There is the option of down-regulating the Sterling to 30 amps but if you do that you might as well buy a Victron Orion at 30 amps. So I sold my Sterling and bought the Victron. It's a neater unit and with Bluetooth you can easily monitor things, change settings and upgrade firmware.

If you really need to maximise your alternator charging then charging the LFP direct is the only good way but that really requires a robust alternator with good cooling, an external regulator and, often, an upgrade to alternator belt arrangements.

 

[DuncanHall]

I agree with Paul. I had a 60 amp Sterling B2B with a 100 amp alternator. Because of the insatiable appetite of the LFP the B2B ran very hot and had to switch itself off to cool down ... over and over again. Also the rule of thumb for alternator capacity to avoid overheating the alternator is 2:1. So that would be a 120 amp alternator to give sufficient headroom for a 60 amp B2B. There is the option of down-regulating the Sterling to 30 amps but if you do that you might as well buy a Victron Orion at 30 amps. So I sold my Sterling and bought the Victron. It's a neater unit and with Bluetooth you can easily monitor things, change settings and upgrade firmware.

If you really need to maximise your alternator charging then charging the LFP direct is the only good way but that really requires a robust alternator with good cooling, an external regulator and, often, an upgrade to alternator belt arrangements.

Thanks all

I will go with the 30A Orion. It means that my Stirling Battery to Battery Charger is now redundant. On reflection running the engine to recharge is poor compared to running the honda Generator which feeds the multiplus delivering 70A.

I have a 60A alternator at present and it may result in slightly less charge.

 

[Pete7]

I have a 60A alternator at present and it may result in slightly less charge.

Swopped out our Volvo alternator for one of these 100A, although it came new from a Neil on here. It just gives a bit more headroom for running the Victron Orion DC>DC. Oh and the Victrons are hot, mine is mounted on the outside of the nav seat and has a 3" hole behind it so reasonable air flow yet still measured 59'c. I have a small pc fan to install to assist in cooling the Orion.

12V 100 AMP UPRATED VOLVO PENTA ALTERNATOR A3673

Pete

 

[geem]

Swopped out our Volvo alternator for one of these 100A, although it came new from a Neil on here. It just gives a bit more headroom for running the Victron Orion DC>DC. Oh and the Victrons are hot, mine is mounted on the outside of the nav seat and has a 3" hole behind it so reasonable air flow yet still measured 59'c. I have a small pc fan to install to assist in cooling the Orion.

12V 100 AMP UPRATED VOLVO PENTA ALTERNATOR A3673

Pete

We haven't installed it yet but we have an alternator off a bus. Our boat is 24v. The 24v bus alternator is rated at 155A at 24v (so 310A in 12v money).
We are fitting it so we can run the 220v watermaker through the 3kw inverter with the engine running. We may flip to lithium in the future in which case a couple of 30A B2Bs will work nicely with no alternator mods. The alternator also has a duct connection for cooling air that may be handy.