Propulsion Power

[peterboat]

1 hour ago, Antrepat said:

 

I think the whine of a belt drive might be the kind of compromise one would have to make if the belt drive motor were the more affordable choice compared with the direct drive ones.

 

Does he want to do mine?  Would same me a lot of trouble...

He is a nice guy which has been his downfall in some ways, its a shame, when you googled him did you read about his electric bike?

[IanD]

22 minutes ago, peterboat said:

He is a nice guy which has been his downfall in some ways, its a shame, when you googled him did you read about his electric bike?

He does seem to have been thoroughly screwed over... ?

[peterboat]

1 hour ago, IanD said:

He does seem to have been thoroughly screwed over... ?

I have been talking to James where my batteries came from this evening, it would appear that Cedric and Arvind are resurrecting the Agni name again so maybe we will be seeing more Cedric motors on the go again. 

[Antrepat]

5 hours ago, Tony Brooks said:

My comment on the last few posts is that if I were going for electric traction I would now not even consider lead acids. The full charge time and the danger of sulphation is just too great when compared with LiFePo4. I would rather stick with diesel while I saved up.

 

Of course the lithiums will require better charge control than LA would but for solar charging or generator charging lithiums win hands down once the charge control is sorted.

 

From the research I've done so far, I'd absolutely agree that LiFePO4 is the technology of choice, but they are just so expensive.  If I waited until I'd saved up for them, I might be able to implement conversion in about ten years' time, which is equivalent to "just forget the whole idea".   I'm going to look into the way Peter got his - second hand ex-vehicle traction battery packs - but the affordability is why I was exploring lead carbon.  I haven't really done my homework on the "tubular flooded" traction battery type yet but Ian said they're cheaper than any other type and possibly better in some respects.

 

I got interested in the Lead Carbon technology in an effort to balance affordability with at least some avoidance of precisely the issues that Tony points out with sulphation and charge rate.  According to Victron, whom most seem to respect, "replacing the active material of the negative plate by a lead carbon composite potentially reduces sulfation and improves charge acceptance of the negative plate".  Hmm, "potentially", and then it goes on to offer no data on the matter of sulphation, but it does claim that "tests have shown that our lead carbon batteries do withstand at least five hundred 100% DoD cycles."  Anyway, things that shorten life are incomplete charging (sulphate accumulates), discharging very deeply and often (promoting corrosion of the positive plate by the acid electrolyte), particularly without full recovery, and leaving the battery in a Partial State Of Charge (PSOC, promoting growth of permanent lead sulphate crystals on the negative plate).

 

I would not be continuously cruising - it's a holiday and weekend boat - and I would have solar so extended periods of PSOC should not happen - even in dull weather the battery would be fully recharged over a few days, and would have the opportunity for a full absorption charge phase after every trip (sequence of days of navigation).  During a trip, though, the energy demands would need serious charging daily, with a depth of discharge dependent on how long you want to keep navigating in near-silent electric bliss before starting the generator - belt whine accepted, incidentally, if the non-direct-drive systems are more affordable: I'm not planning on sneaking up on wildlife and it'll be a hell of a lot quieter than a diesel thundering away under my feet.  Setting aside arguments about generators, Victron state that 0.2C is the fastest you should go with their lead carbons if you don't want to damage the battery or shorten its life significantly.  That's a maximum of 20A for a 100Ah battery, meaning a 5hr charge time (not accounting for phased charging, of course, so 5hr will never get 100% charge).  If my understanding of the assembly of large batteries is correct, different combinations in series and parallel to make up a certain voltage and capacity (e.g. 4S4P 12v 100Ah = 48v 400Ah and a bloody big fuse) don't charge at different rates: that still comes down to the recommended charge rate of each battery.  400Ah 48v 0.2C takes the same time as 100Ah 12v 0.2C, but of course needs eight times as much power.

 

When you look at Leoch, the Chinese make, you find some eyebrow-raising claims but datasheets that are vague about some details, which of course should make us suspicious.  For example, Rolls datasheets clearly recommend that their AGM Deep Cycle 12v 210Ah battery (effectively 200Ah) is charged at 40A, which is 0.2C like Victron's lead carbons, but Leoch's datasheet for their Deep Cycle Lead Carbon AGM+Gel range claims 0.5C charging for three hours - that'd be 200A at 48v (10kW) for a 400Ah battery.  I've never seen a charger that can deliver anything like that but I'm guessing people set up parallel charging with multiple units; and you'd need the building-site generator to supply it anyway.  On a 30ft boat?  I don't think so, more like one of those compact 3kW Champion ones that can run on propane (reduced power, I know, but I already have gas and I would rather not store petrol at all).  The Leoch datasheet does not state whether 0.5 is a maximum, a recommended, or even just a theoretical rate.  Who is going to spend maybe £3k on batteries to have them explode (or whatever happens) when you try to charge them at the quoted rate, even if you could find a big enough charger?  I was going to get in touch with Leoch UK and ask but the Captcha on their contact page was broken.  Not encouraging at all.

 

Leoch also do a range of what they call Pure Lead Carbon batteries, which they claim can do 2500 cycles at 60% DoD, are more resilient against Partial State Of Charge sulphation, and achieve a 90% charge in one hour.  Pull the other one, lads - that's 0.9C.  Really?? That'd be 90A at 12v for a single 100Ah, but a completely unachievable 17.3kW (360A at 48v) for 400Ah at 48v.  The PSOC resilience and long life (even if it's only half of what they quote) would be advantageous, but making up a big battery with them and hoping to charge them that quickly is just ridiculous.

 

I've been looking at the batteries issue from the wrong end.  I was thinking about what's the biggest, most high-tech battery I can afford, because it's bound to be better, right?  Wrong.  Yes, LiFePO4 would be best but I just can't afford them.  Maybe a second hand option exists and I'll look into it, but I may have to stick with conventional types, and maybe the usage pattern makes even the least fancy an acceptable option after all.  That pattern is unlikely to provoke big problems with sulphation because there will always be solar charging going during the day gently to bring the battery back up to fully-charged, equalised, desulphated health when I'm not using the boat during the working week.  I therefore don't need to prioritize getting a technology that's particularly resilient to sulphation, including PSOC since the batteries will never remain at low charge for any time.  I can't afford nor do I have room for a 10kW generator with multiple heavy-duty chargers, so there's also no need to prioritize getting a particularly fast-charging type: 0.2C will be just fine.  I accept the compromise of needing to run a smaller generator for longer: that's what's practical, affordable, and in any case a soundproofed generator running at its optimal speed will be less intrusive than the diesel at 20% efficiency thundering under my feet the entire time, especially if it's at the bow.

 

I'll look into flooded 2v traction batteries - I take it these are the kind used in forklifts and suchlike - and into second hand ex-vehicle lithium packs.

[Antrepat]

2 hours ago, peterboat said:

He is a nice guy which has been his downfall in some ways, its a shame, when you googled him did you read about his electric bike?

 

Sadly nice guys with clever inventions don't mix well with greedy, integrity-free, capitalist toerags.  It looks like Cedric trusted the wrong people and they stole his IP.

 

I did see about the bike, yes, but I've not read about it in detail yet.

[peterboat]

36 minutes ago, Antrepat said:

 

From the research I've done so far, I'd absolutely agree that LiFePO4 is the technology of choice, but they are just so expensive.  If I waited until I'd saved up for them, I might be able to implement conversion in about ten years' time, which is equivalent to "just forget the whole idea".   I'm going to look into the way Peter got his - second hand ex-vehicle traction battery packs - but the affordability is why I was exploring lead carbon.  I haven't really done my homework on the "tubular flooded" traction battery type yet but Ian said they're cheaper than any other type and possibly better in some respects.

 

I got interested in the Lead Carbon technology in an effort to balance affordability with at least some avoidance of precisely the issues that Tony points out with sulphation and charge rate.  According to Victron, whom most seem to respect, "replacing the active material of the negative plate by a lead carbon composite potentially reduces sulfation and improves charge acceptance of the negative plate".  Hmm, "potentially", and then it goes on to offer no data on the matter of sulphation, but it does claim that "tests have shown that our lead carbon batteries do withstand at least five hundred 100% DoD cycles."  Anyway, things that shorten life are incomplete charging (sulphate accumulates), discharging very deeply and often (promoting corrosion of the positive plate by the acid electrolyte), particularly without full recovery, and leaving the battery in a Partial State Of Charge (PSOC, promoting growth of permanent lead sulphate crystals on the negative plate).

 

I would not be continuously cruising - it's a holiday and weekend boat - and I would have solar so extended periods of PSOC should not happen - even in dull weather the battery would be fully recharged over a few days, and would have the opportunity for a full absorption charge phase after every trip (sequence of days of navigation).  During a trip, though, the energy demands would need serious charging daily, with a depth of discharge dependent on how long you want to keep navigating in near-silent electric bliss before starting the generator - belt whine accepted, incidentally, if the non-direct-drive systems are more affordable: I'm not planning on sneaking up on wildlife and it'll be a hell of a lot quieter than a diesel thundering away under my feet.  Setting aside arguments about generators, Victron state that 0.2C is the fastest you should go with their lead carbons if you don't want to damage the battery or shorten its life significantly.  That's a maximum of 20A for a 100Ah battery, meaning a 5hr charge time (not accounting for phased charging, of course, so 5hr will never get 100% charge).  If my understanding of the assembly of large batteries is correct, different combinations in series and parallel to make up a certain voltage and capacity (e.g. 4S4P 12v 100Ah = 48v 400Ah and a bloody big fuse) don't charge at different rates: that still comes down to the recommended charge rate of each battery.  400Ah 48v 0.2C takes the same time as 100Ah 12v 0.2C, but of course needs eight times as much power.

 

When you look at Leoch, the Chinese make, you find some eyebrow-raising claims but datasheets that are vague about some details, which of course should make us suspicious.  For example, Rolls datasheets clearly recommend that their AGM Deep Cycle 12v 210Ah battery (effectively 200Ah) is charged at 40A, which is 0.2C like Victron's lead carbons, but Leoch's datasheet for their Deep Cycle Lead Carbon AGM+Gel range claims 0.5C charging for three hours - that'd be 200A at 48v (10kW) for a 400Ah battery.  I've never seen a charger that can deliver anything like that but I'm guessing people set up parallel charging with multiple units; and you'd need the building-site generator to supply it anyway.  On a 30ft boat?  I don't think so, more like one of those compact 3kW Champion ones that can run on propane (reduced power, I know, but I already have gas and I would rather not store petrol at all).  The Leoch datasheet does not state whether 0.5 is a maximum, a recommended, or even just a theoretical rate.  Who is going to spend maybe £3k on batteries to have them explode (or whatever happens) when you try to charge them at the quoted rate, even if you could find a big enough charger?  I was going to get in touch with Leoch UK and ask but the Captcha on their contact page was broken.  Not encouraging at all.

 

Leoch also do a range of what they call Pure Lead Carbon batteries, which they claim can do 2500 cycles at 60% DoD, are more resilient against Partial State Of Charge sulphation, and achieve a 90% charge in one hour.  Pull the other one, lads - that's 0.9C.  Really?? That'd be 90A at 12v for a single 100Ah, but a completely unachievable 17.3kW (360A at 48v) for 400Ah at 48v.  The PSOC resilience and long life (even if it's only half of what they quote) would be advantageous, but making up a big battery with them and hoping to charge them that quickly is just ridiculous.

 

I've been looking at the batteries issue from the wrong end.  I was thinking about what's the biggest, most high-tech battery I can afford, because it's bound to be better, right?  Wrong.  Yes, LiFePO4 would be best but I just can't afford them.  Maybe a second hand option exists and I'll look into it, but I may have to stick with conventional types, and maybe the usage pattern makes even the least fancy an acceptable option after all.  That pattern is unlikely to provoke big problems with sulphation because there will always be solar charging going during the day gently to bring the battery back up to fully-charged, equalised, desulphated health when I'm not using the boat during the working week.  I therefore don't need to prioritize getting a technology that's particularly resilient to sulphation, including PSOC since the batteries will never remain at low charge for any time.  I can't afford nor do I have room for a 10kW generator with multiple heavy-duty chargers, so there's also no need to prioritize getting a particularly fast-charging type: 0.2C will be just fine.  I accept the compromise of needing to run a smaller generator for longer: that's what's practical, affordable, and in any case a soundproofed generator running at its optimal speed will be less intrusive than the diesel at 20% efficiency thundering under my feet the entire time, especially if it's at the bow.

 

I'll look into flooded 2v traction batteries - I take it these are the kind used in forklifts and suchlike - and into second hand ex-vehicle lithium packs.

It is hard work working out what is best for you and at a price you can afford. A weekend boat has freedoms that a livaboard life doesnt allow, a cheaper motor you arnt cruising constantly, smaller battery bank because it will recharge over the week, a genny on the bow or bank will work for you.

I will keep an eye out for batteries and motors for you.

Edited February 28, 2021 by peterboat

[Antrepat]

2 minutes ago, peterboat said:

It is hard work working out what is best for you and at a price you can afford. A weekend boat has freedoms that a livaboard life doesnt allow, a cheaper motor you arnt cruising constantly, smaller battery bank because it will recharge over the week, a genny on the bow or bank will work for you

 

Exactly.

 

Hard work but fun.

 

Would you be able to point me to likely sellers of second hand vehicle packs?  I found one offering ex-Tesla packs for eye-watering amounts.

[magnetman]

Pod drive and Gel batteries is the way I am doing it but it's a secondary propulsion system.  I'm leaving the existing shaft lines intact (twin screw diesel vessel used on the Thames) and adding a pod between them for the stealth mode. 

 

I reckon a 4kw pod in a narrow boat rudder would be a nice thing to have, with existing diesel and drive line left in place. 

 

Yes there will be some drag but no it won't make much difference at canal speeds. I'd be intrigued to see how the rudder behaves though if it was a fixed prop. I reckon it would be ok and having the pod in the rudder itself would-be amazing for close quarters maneouvering. 

 

A motor in a pod is going to be quieter too. 

 

This is for a boat which already has a diesel install. For a new build maybe different but I still think a diesel on a shaft is a very handy thing to have in a boat. 

 

 

The rudder is most critical at slow speeds and in this situation you would be using the electric going slowly anyway which would enhance the effectiveness of the rudder. 

 

 

Edited February 28, 2021 by magnetman

[peterboat]

1 minute ago, magnetman said:

Pod drive and Gel batteries is the way I am doing it but it's a secondary propulsion system.  I'm leaving the existing shaft lines intact (twin screw diesel vessel used on the Thames) and adding a pod between them for the stealth mode. 

 

I reckon a 4kw pod in a narrow boat rudder would be a nice thing to have, with existing diesel and drive line left in place. 

 

Yes there will be some drag but no it won't make much difference at canal speeds. 

 

A motor in a pod is going to be quieter too. 

 

This is for a boat which already has a diesel install. For a new build maybe different but I still think a diesel on a shaft is a very handy thing to have in a boat. 

 

 

25% license discount Andrew is a big winner for getting rid of the noisy diesel engine

[magnetman]

Yes £200 a year saving for a boat with mains electric on the mooring but this boat is never attached to the bank with anything other than ropes. I'm definitely keeping the diesels for the foreseeable. 

Edited February 28, 2021 by magnetman

[peterboat]

2 minutes ago, magnetman said:

Yes £200 a year saving for a boat with mains electric on the mooring but this boat is never attached to the bank with anything other than ropes. I'm definitely keeping the diesels for the foreseeable. 

Yes its defo horses for courses but in your case its the way forward, for Antrepat weekend cruise back to base solar charges over the week

[Antrepat]

1 hour ago, peterboat said:

25% license discount Andrew is a big winner for getting rid of the noisy diesel engine

 

Hang on, you wot?  CRT licence, you mean?  I didn't know there was a discount for going electric...

[Antrepat]

6 hours ago, Antrepat said:

I'll look into flooded 2v traction batteries - I take it these are the kind used in forklifts and suchlike - and into second hand ex-vehicle lithium packs.

 

I did some trawling regarding the traction batteries.  A few places are selling them online (as opposed to industrial suppliers who will quote on demand).  PB Battery Solutions have a 48v 420Ah bank for £2,397.60. and Tayna sell both banks and appropriate cells individually for £122.27 (£2,994,47 for 24).  This type seems to be highly standardized, which is a change from what it seems to be like for car and other monobloc batteries these days, and the cell design is intended for big currents, deep cycles, and repeated recharging.  An equivalent LiFePO4 bank looks like it would cost well north of £10k, the Leoch Lead Carbon AGM+Gels (the ones with supposedly a 0.5C charge rate) are £2,600 from Tayna, and the Pure Carbons (0.9C?  Nah.) are £3,840 from Alpha Batteries.

 

What's missing is data.  No one is specifying what the charge rate for these traction cells is, or continuous discharge, or any of the usual stuff you expect to find on a good data sheet.  If the charge rate is only 0.1C then that's no good, is it, because that would mean it would take too long to bulk charge them for the next day's navigation, even with some solar input and charging on the move, whilst not being antisocial and leaving your generator going after 8pm.  Compromises, compromises, pragmatism.

 

I've had no luck at all finding anyone selling used vehicle Lithium battery packs.

 

Incidentally, I found that Agni has a web site, well, page, featuring Cedric Lynch and the Rabadias, giving a factory location and showing a picture of a team of workers, but with no indication of whether there is active production or who is distributing the products.  I see Agni merged with some other lot to form Saietta group in 2015, so I'm assuming that Agni page has just never been taken down.  What I haven't found is anyone in the UK just plain selling Agni or Saietta Lynch-type motors, only Gecko Energy selling Lynch Motor Co motors.  This company has, I think, nothing to do with Cedric Lynch and he receives little or no benefit from its activities so I'm going to read back and look at the various recommendations made during this discussion.

[magnetman]

A friend of mine has dismantled a G-Wiz electric car and is going to use the motor in an electric narrow boat project. 

 

I was impressed by the motor it seems like a nice unit and has a Curtis controller. Heavy item. The car was located for £300 if I recall correctly.

 

Bit of a spaghetti situation with the wiring loom but should be okay.

 

I said do belt drive be he insisted on using a gearbox for some reason. 

 

Oh well we'll see how it goes. Nice motor. 

 

As for batteries the Mitsubishi Outlander packs look interesting but would need rearranging into a different format as wrong voltage (29v). Or maybe you could run the system at this voltage? A bit low really 48v would be better certainly. 

 

Lithium NMC I assume they are (Yuasa LEV40 cells). 

 

£250 for a block of 8:

 

https://www.ebay.co.uk/itm/Lithium-Battery-Pack-8x-LEV40-Yuasa-cells-Mitsubishi-Outlander-Powerwall-40Ah-/293378651122

 

 

 

[peterboat]

6 hours ago, Antrepat said:

 

I did some trawling regarding the traction batteries.  A few places are selling them online (as opposed to industrial suppliers who will quote on demand).  PB Battery Solutions have a 48v 420Ah bank for £2,397.60. and Tayna sell both banks and appropriate cells individually for £122.27 (£2,994,47 for 24).  This type seems to be highly standardized, which is a change from what it seems to be like for car and other monobloc batteries these days, and the cell design is intended for big currents, deep cycles, and repeated recharging.  An equivalent LiFePO4 bank looks like it would cost well north of £10k, the Leoch Lead Carbon AGM+Gels (the ones with supposedly a 0.5C charge rate) are £2,600 from Tayna, and the Pure Carbons (0.9C?  Nah.) are £3,840 from Alpha Batteries.

 

What's missing is data.  No one is specifying what the charge rate for these traction cells is, or continuous discharge, or any of the usual stuff you expect to find on a good data sheet.  If the charge rate is only 0.1C then that's no good, is it, because that would mean it would take too long to bulk charge them for the next day's navigation, even with some solar input and charging on the move, whilst not being antisocial and leaving your generator going after 8pm.  Compromises, compromises, pragmatism.

 

I've had no luck at all finding anyone selling used vehicle Lithium battery packs.

 

Incidentally, I found that Agni has a web site, well, page, featuring Cedric Lynch and the Rabadias, giving a factory location and showing a picture of a team of workers, but with no indication of whether there is active production or who is distributing the products.  I see Agni merged with some other lot to form Saietta group in 2015, so I'm assuming that Agni page has just never been taken down.  What I haven't found is anyone in the UK just plain selling Agni or Saietta Lynch-type motors, only Gecko Energy selling Lynch Motor Co motors.  This company has, I think, nothing to do with Cedric Lynch and he receives little or no benefit from its activities so I'm going to read back and look at the various recommendations made during this discussion.

I think I will be talking to Cedric this week, if I do i will ask him about motors for you. You can buy the traction batteries from local suppliers which I did previously, the problem is they arnt that good in reality, plus they are big and gas off hydrogen so have to be vented to the outside.

[magnetman]

Another motor which looks interesting is the Perm 132. A while ago someone was selling these still in their packing crates for a really good price on eBay. 

 

They turn up now and then. Very powerful brushed motors. Not sure if they are a copy of Lynch but they do seem similar. 

[IanD]

7 hours ago, Antrepat said:

 

I did some trawling regarding the traction batteries.  A few places are selling them online (as opposed to industrial suppliers who will quote on demand).  PB Battery Solutions have a 48v 420Ah bank for £2,397.60. and Tayna sell both banks and appropriate cells individually for £122.27 (£2,994,47 for 24).  This type seems to be highly standardized, which is a change from what it seems to be like for car and other monobloc batteries these days, and the cell design is intended for big currents, deep cycles, and repeated recharging.  An equivalent LiFePO4 bank looks like it would cost well north of £10k, the Leoch Lead Carbon AGM+Gels (the ones with supposedly a 0.5C charge rate) are £2,600 from Tayna, and the Pure Carbons (0.9C?  Nah.) are £3,840 from Alpha Batteries.

 

What's missing is data.  No one is specifying what the charge rate for these traction cells is, or continuous discharge, or any of the usual stuff you expect to find on a good data sheet.  If the charge rate is only 0.1C then that's no good, is it, because that would mean it would take too long to bulk charge them for the next day's navigation, even with some solar input and charging on the move, whilst not being antisocial and leaving your generator going after 8pm.  Compromises, compromises, pragmatism.

 

I've had no luck at all finding anyone selling used vehicle Lithium battery packs.

 

Incidentally, I found that Agni has a web site, well, page, featuring Cedric Lynch and the Rabadias, giving a factory location and showing a picture of a team of workers, but with no indication of whether there is active production or who is distributing the products.  I see Agni merged with some other lot to form Saietta group in 2015, so I'm assuming that Agni page has just never been taken down.  What I haven't found is anyone in the UK just plain selling Agni or Saietta Lynch-type motors, only Gecko Energy selling Lynch Motor Co motors.  This company has, I think, nothing to do with Cedric Lynch and he receives little or no benefit from its activities so I'm going to read back and look at the various recommendations made during this discussion.

The problem with LA batteries is not just the charging time, it's the absorption time needed to get them up to 100% SOC and hold them there, which is needed to avoid sulphation.

 

The Leoch PLC batteries (batterystore.co.uk are the cheapest UK source, are partnered with Leoch) have more data available under other labels they're sold under such as Outback (Australian). If you dig into their data sheets, maximum recommended charge current is 0.25C, with about 4h absorption time at 100% SOC. But they are sealed. However this is little real-world experience of them in boat applications because they're relatively new, and they fall into the same "neither fish nor fowl" problem as advanced AGM/cell cells -- they're a lot more expensive than traction cells (about 2x the cost) and still have a lot of the LA disadvantages, and if you're going to pay this much you might as well pay even more and use LiFePO4 and get huge benefits (fast charging, higher efficiency, no absorption to speak of)

 

Traction cells (Tayna cheapest, or pbbatterysolutions?) are designed to be charged back to 100% overnight (>8h charging time) every night, and have similar maximum charge rates and if anything even longer absorption time. This is because they are very tall (typically a couple of feet) and rely on gassing at full charge to circulate the acid, and even then this takes a long time to equalise concentration over the full height. Which also means they *have* to be taken to the bubbling stage regularly to avoid sulphation, which is why fan extraction/venting is needed to prevent building up of explosive gases. Then you almost certainly need an automatic watering system to keep them topped up, which adds to the cost.

 

Having said this, if you do all this (and can put up with the long charging/equalisation times) they're relatively cheap and do last a long time -- when I spoke to Hybrid Marine they said they've got boats out there (all parallel hybrids) after 8-10 years still on their original set of batteries, though obviously without knowing how much they've been used you need to take this with a pinch of salt.

 

https://www.hybrid-marine.co.uk/index.php/products/narrowboat

 

Here's a source for BEV battery packs, much cheaper than new but still pretty expensive.

 

https://www.secondlife-evbatteries.com/collections/ev-battery/Module

 

Bear in mind that these are almost all Li-ion, which need *extreme* care with charging/discharging/protection because if things go wrong the consequences can be catastrophic (battery fires), and there may be consequences for boat insurance because of this -- an issue not often mentioned but I think everyone knows what insurance companies are like, if you don't tell them about the batteries they'll probably refuse any claim. I don't know if the companies who cover UK canals have much experience of Li-ion, but lumpy water companies do and they're very wary of them, especially with home-brewed BMS. I suspect this is the reason why none of the reputable builders of electric boats in the UK have gone down this route, they all use LiFePO4 (the ones who do a "proper job" i.e. an expensive one) -- the cheapskates use LA cells (PLC or traction) with all their disadvantages.

 

The real problem with LA in an electric boat/hybrid where charging is usually from a generator is the long charging/equalisation times -- depending on charging rates, generator run time is at least 2x what you'd predict by dividing required charge by maximum charge rate (can easily be as much as 3x, especially allowing for round-trip energy losses), and for a large part of this time the batteries aren't accepting much current (and it's tailing off) so the generator is running well below full power, bad for efficiency -- as well as wasting fuel, long run times mean servicing is needed a lot more often. You also have to pay close attention to your battery charging regime, making sure to fully charge to 100% SOC and equalise regularly.

 

In comparison LiFePO4 can just be treated as a power bank -- so long as you don't overcharge or overdischarge them (which is why a proper BMS is needed) they don't really care much what SoC they're at, have much higher round-trip efficiency, and need next to no equalisation or care and attention. The biggest bonus is having to run the generator for much shorter times than LA, which is pretty much the entire point of going electric/series hybrid in the first place.

 

Unfortunately they do cost more ?

Edited March 1, 2021 by IanD

[peterboat]

1 hour ago, IanD said:

The problem with LA batteries is not just the charging time, it's the absorption time needed to get them up to 100% SOC and hold them there, which is needed to avoid sulphation.

 

The Leoch PLC batteries (batterystore.co.uk are the cheapest UK source, are partnered with Leoch) have more data available under other labels they're sold under such as Outback (Australian). If you dig into their data sheets, maximum recommended charge current is 0.25C, with about 4h absorption time at 100% SOC. But they are sealed. However this is little real-world experience of them in boat applications because they're relatively new, and they fall into the same "neither fish nor fowl" problem as advanced AGM/cell cells -- they're a lot more expensive than traction cells (about 2x the cost) and still have a lot of the LA disadvantages, and if you're going to pay this much you might as well pay even more and use LiFePO4 and get huge benefits (fast charging, higher efficiency, no absorption to speak of)

 

Traction cells (Tayna cheapest, or pbbatterysolutions?) are designed to be charged back to 100% overnight (>8h charging time) every night, and have similar maximum charge rates and if anything even longer absorption time. This is because they are very tall (typically a couple of feet) and rely on gassing at full charge to circulate the acid, and even then this takes a long time to equalise concentration over the full height. Which also means they *have* to be taken to the bubbling stage regularly to avoid sulphation, which is why fan extraction/venting is needed to prevent building up of explosive gases. Then you almost certainly need an automatic watering system to keep them topped up, which adds to the cost.

 

Having said this, if you do all this (and can put up with the long charging/equalisation times) they're relatively cheap and do last a long time -- when I spoke to Hybrid Marine they said they've got boats out there (all parallel hybrids) after 8-10 years still on their original set of batteries, though obviously without knowing how much they've been used you need to take this with a pinch of salt.

 

https://www.hybrid-marine.co.uk/index.php/products/narrowboat

 

Here's a source for BEV battery packs, much cheaper than new but still pretty expensive.

 

https://www.secondlife-evbatteries.com/collections/ev-battery/Module

 

Bear in mind that these are almost all Li-ion, which need *extreme* care with charging/discharging/protection because if things go wrong the consequences can be catastrophic (battery fires), and there may be consequences for boat insurance because of this -- an issue not often mentioned but I think everyone knows what insurance companies are like, if you don't tell them about the batteries they'll probably refuse any claim. I don't know if the companies who cover UK canals have much experience of Li-ion, but lumpy water companies do and they're very wary of them, especially with home-brewed BMS. I suspect this is the reason why none of the reputable builders of electric boats in the UK have gone down this route, they all use LiFePO4 (the ones who do a "proper job" i.e. an expensive one) -- the cheapskates use LA cells (PLC or traction) with all their disadvantages.

 

The real problem with LA in an electric boat/hybrid where charging is usually from a generator is the long charging/equalisation times -- depending on charging rates, generator run time is at least 2x what you'd predict by dividing required charge by maximum charge rate (can easily be as much as 3x, especially allowing for round-trip energy losses), and for a large part of this time the batteries aren't accepting much current (and it's tailing off) so the generator is running well below full power, bad for efficiency -- as well as wasting fuel, long run times mean servicing is needed a lot more often. You also have to pay close attention to your battery charging regime, making sure to fully charge to 100% SOC and equalise regularly.

 

In comparison LiFePO4 can just be treated as a power bank -- so long as you don't overcharge or overdischarge them (which is why a proper BMS is needed) they don't really care much what SoC they're at, have much higher round-trip efficiency, and need next to no equalisation or care and attention. The biggest bonus is having to run the generator for much shorter times than LA, which is pretty much the entire point of going electric/series hybrid in the first place.

 

Unfortunately they do cost more ?

I agree with you Ian which is why i took the route I did all those years ago. The full traction route might work for the OP as he will be using it at weekends only so it would have week to charge up on solar. I had these batteries as leisure batteries and they did 10 years plus but were getting tired at the end, the issue for me is they are heavy 12 batteries equals over a ton 24 is a couple of tons and and are big! they will be in I dont know where?

[IanD]

40 minutes ago, peterboat said:

I agree with you Ian which is why i took the route I did all those years ago. The full traction route might work for the OP as he will be using it at weekends only so it would have week to charge up on solar. I had these batteries as leisure batteries and they did 10 years plus but were getting tired at the end, the issue for me is they are heavy 12 batteries equals over a ton 24 is a couple of tons and and are big! they will be in I dont know where?

LA traction cells are certainly big and heavy and need careful planning in to fit them into a boat, they're difficult to add on afterwards. The banks used by Hybrid Marine (24 x EPzS 775) weigh about a ton, and cost with auto topup and venting is about 5 grand...

 

Charging by solar during the week (assuming big enough solar panels and enough sun!) and cruising at weekends does avoid the generator problem, also the long equalisation time. But this will need a fairly sophisticated and reliable charging system to charge and then absorb/equalise them while unattended, a week (or more) of overcharging would be disastrous...

 

I do worry about people suggesting that using secondhand Li-ion BEV batteries on a boat is a good idea. When built into a car the BMS is designed/verified/guaranteed by the manufacturer, who has a huge incentive to do it properly (which means, not cheapskate -- the electrics are a typically at least a third of the cost of the car) because having them catch fire and burn cars out is bad publicity -- and the insurance companies are aware of all this and allow for it. They also make them in large volumes so any bugs in the system are likely to be found and fixed.

 

Now consider people using these Li-ion packs second-hand on their boats with a DIY (or bought-in from bits) BMS, and doing it all on the cheap -- which means the reliability/fault-tolerance/protection/idiot-proofing is likely to be to a far lower standard than in a car, with very few of them out there to find any problems. And when things go wrong with Li-ion they go really wrong, putting out a battery fire is not for the faint of heart -- or even many (most?) fire brigades.

 

Put all this together and I very much doubt than any insurance company would touch Li-ion on a narrowboat with a bargepole, unless it was a properly designed and installed system from a reputable commercial supplier who can demonstrate the same design/safety/regulation standards as Li-ion cells in BEV. Which costs an absolute fortune to do, and certainly wouldn't be the cheap solution that everyone is looking for.

 

LiFePO4 is a different matter, these are *much* safer and easier to deal with. But almost all BEVs that these battery packs are coming from (Tesla, VW, BMW) are Li-ion because the higher power density is critical for cars...

Edited March 1, 2021 by IanD

[Antrepat]

3 hours ago, peterboat said:

I think I will be talking to Cedric this week, if I do i will ask him about motors for you. You can buy the traction batteries from local suppliers which I did previously, the problem is they arnt that good in reality, plus they are big and gas off hydrogen so have to be vented to the outside.

 

Somehow feels wrong bothering the man himself with individual questions, but if you think he won't mind saying what the situation is...!

 

They aren't that good?  Well they are wet cells, albeit with "tubular" electrodes, I suppose, with all the issues that come with that.  The achievable charging rate is an issue.  Finding out what it is seems difficult enough, but despite what people have been saying about AGMs not being suitable and whatnot, the plain fact of the matter is that I can't afford lithium and won't be able to, and it's these other more advanced lead acid technologies that seem to permit a charging rate that makes the whole idea practicable: it needs to be 0,2C, 0.1C just wouldn't work.  I don't believe for a moment that Leoch SLCAs can do 0.5C, let alone that their pure lead carbons can do 0.9C.  Does anyone?

 

Also, yes, it had been bothering me, hydrogen accumulating in the same engine bay as a potentially sparky motor doesn't sound like a good idea if it were allowed to concentrate.  All lead acids vent hydrogen, though, don't they, no matter if they are AGMs, gels, standard wet cells, lead carbon, or what?  I suppose the answer is just to install a quiet fan so there's always an outflow.  

[Tony Brooks]

8 minutes ago, Antrepat said:

 

Also, yes, it had been bothering me, hydrogen accumulating in the same engine bay as a potentially sparky motor doesn't sound like a good idea if it were allowed to concentrate.  All lead acids vent hydrogen, though, don't they, no matter if they are AGMs, gels, standard wet cells, lead carbon, or what?  I suppose the answer is just to install a quiet fan so there's always an outflow.  

 

As hydrogen is considerably lighter than air I would have though providing you organised decent engine room vents above the deck board level the hydrogen would naturally disperse. Any fan would have to be explosion proof or you would have to blow into the bilge so any hydrogen is vented through a passive vent. You would also have to take steps when working around the batteries to disperse any local pockets of hydrogen.

[Alan de Enfield]

13 minutes ago, Antrepat said:

I suppose the answer is just to install a quiet fan so there's always an outflow.  

 

Most boats have explosion proof 'bilge blowers' that you run for 10 minutes before starting the engine.

 

At around £20-£30 they are not an expensive accessory to ensure that your bilges don't 'explode'.

 

What Is A Bilge Blower On A Boat & What It's Used For! (bornagainboating.com)

[Mad Harold]

1 hour ago, Alan de Enfield said:

 

Most boats have explosion proof 'bilge blowers' that you run for 10 minutes before starting the engine.

 

At around £20-£30 they are not an expensive accessory to ensure that your bilges don't 'explode'.

 

What Is A Bilge Blower On A Boat & What It's Used For! (bornagainboating.com)

Looked at a Freeman cruiser some time ago (Ford petrol carburated engine) and that was fitted with a bilge blower,but configured so that it was a "bilge sucker".

Switched on five minutes before starting and again for five minutes after engine shutdown.

[Alan de Enfield]

56 minutes ago, Mad Harold said:

Looked at a Freeman cruiser some time ago (Ford petrol carburated engine) and that was fitted with a bilge blower,but configured so that it was a "bilge sucker".

Switched on five minutes before starting and again for five minutes after engine shutdown.

 

 

I am very surprised that in general NB's down have them fitted.

 

I thing all bilge-blowers are what you are calling bilge-suckers, the blow the bilge air out of the boat.

They are piped to the 'outside'.

 

I have one in the front of each engine.

 

 

Edited March 1, 2021 by Alan de Enfield

[IanD]

3 hours ago, Antrepat said:

 

Somehow feels wrong bothering the man himself with individual questions, but if you think he won't mind saying what the situation is...!

 

They aren't that good?  Well they are wet cells, albeit with "tubular" electrodes, I suppose, with all the issues that come with that.  The achievable charging rate is an issue.  Finding out what it is seems difficult enough, but despite what people have been saying about AGMs not being suitable and whatnot, the plain fact of the matter is that I can't afford lithium and won't be able to, and it's these other more advanced lead acid technologies that seem to permit a charging rate that makes the whole idea practicable: it needs to be 0,2C, 0.1C just wouldn't work.  I don't believe for a moment that Leoch SLCAs can do 0.5C, let alone that their pure lead carbons can do 0.9C.  Does anyone?

 

Also, yes, it had been bothering me, hydrogen accumulating in the same engine bay as a potentially sparky motor doesn't sound like a good idea if it were allowed to concentrate.  All lead acids vent hydrogen, though, don't they, no matter if they are AGMs, gels, standard wet cells, lead carbon, or what?  I suppose the answer is just to install a quiet fan so there's always an outflow.  

Most LA batteries are happy being charged at 0.25C, including traction, AGM, gel and lead-carbon, so long as there's proper control of absorption/float voltages to prevent overcharging. The bigger PLC batteries can be charged at 0.25C, see attached data sheet from Outback (badged Leoch pure lead carbon).

 

Sealed batteries like the Leoch PLC (or AGM or gel?) don't give off any gases in normal operation and don't need any venting. Traction cells do, and do.

enegycellPLC_specsheet.pdf

Edited March 1, 2021 by IanD