Lithiums only beat LA if you don't have enough solar

[Dr Bob]

3 minutes ago, Mike the Boilerman said:

Thinking about my hobby boats, lithium would suit them very well for a completely different reason. 

 

On finishing a day's cruise out on a hobby boat I find I frequently moor up on the home mooring, stay for a while using leccy on the fridge, puter, lights, heater etc, then go home leaving LA batts partly charged. Solar partly overcomes this problem but lithium wouldn't care.

......but that affects your liveaboard as well.

You never have to think about it being fully charged.

[MtB]

3 minutes ago, Dr Bob said:

......but that affects your liveaboard as well.

You never have to think about it being fully charged.

 

I never think about it anyway!

 

 

To expand on this, nine months of the year the solar has them fully charged by midday every day, if not by 7am. In winter I run the whispergen once or twice a day to get hot water and this charges the batts too. Not always to 100% but in my experience heavily sulphated LA batts reach a stage when they don't get any worse. Mine are like this now. 

 

 

[Dr Bob]

I never think about it.

[jetzi]

On 02/10/2019 at 15:40, Dr Bob said:

Its not just the winter though.

The last two days have been nice in the morning but pouring down with leaden skies by 3pm. We did 2 hours motoring Monday and 3 hrs Tuesday with around 140Ahr out overnight - on both nights before. So at the end of each run (around 2ish) we were 90% charged. There was not +ve charge from the panels after that (TV/sky dish on). Today Wednesday, we are parked up again by 2pm at again 90% full.

For Li's it is not an issue. YOU DONT HAVE TO GET TO 100%.

With LA's, on the 3rd day of not getting to 100% you would be needing to run the engine if no sun, so even early october you cant rely on solar.

 

.....having said all that, the sun has come out again this afternoon so I'll probably get up to 95% (and the tail current will kill the input from a 1500W solar array on an LA bank). Did I mention parking under trees?

OK, I hear the advantage of not needing to get to 100% with Li. But how many people get their LAs up to 100% more than once a week (at most)? Still, I see that you can stop worrying about your battery capacity once you have Li's.

 

Saying that the tail current will kill the input is a non-issue with solar in my view, because the energy is free, quiet and the generation equipment requires little to no maintenance, unlike generation with your alternator.

 

I think there have been a number of good points made but none so far that (to me) justify the cost of Li's. I think I probably need to get some much more accurate figures of how much a LA vs a Li system would cost me and how long I'd expect it to last.

 

 

One thing that I probably should also mention is that we only expect to keep our boat 4-5 years before we upgrade. So batteries that last a thousand years are a bit wasted on us. So when I'm calculating the cost of LAs vs Lis, I really need to amortise over 5 years - it doesn't help me much if Li's save me money over 20 years. Of course the next owners would appreciate them I'm sure, and that might add a bit of value to the sale price of the boat, but if I was buying a boat I wouldn't put much stock in the quality of the batteries they had on board because you'd have no idea if they had been abused.

I guess what a lot of it comes down to is that I'm not sure it's wise to invest in something fragile - and if you are comparing the cost of LAs and Li's over many years then what you are doing is comparing an investment.

[Alan de Enfield]

44 minutes ago, ivan&alice said:

I think there have been a number of good points made but none so far that (to me) justify the cost of Li's. I think I probably need to get some much more accurate figures of how much a LA vs a Li system would cost me and how long I'd expect it to last.

 

I'm about to replace a couple of my 200/230Ah batteries (Type 635) and found this supplier at £169

Exide - quality brand / name.

 

https://www.ebay.co.uk/itm/143160685253?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

 

I wouldn't be surprised if you could get them at about £150-£160 each if you were buying 4 or 5

[peterboat]

2 hours ago, ivan&alice said:

OK, I hear the advantage of not needing to get to 100% with Li. But how many people get their LAs up to 100% more than once a week (at most)? Still, I see that you can stop worrying about your battery capacity once you have Li's.

 

Saying that the tail current will kill the input is a non-issue with solar in my view, because the energy is free, quiet and the generation equipment requires little to no maintenance, unlike generation with your alternator.

 

I think there have been a number of good points made but none so far that (to me) justify the cost of Li's. I think I probably need to get some much more accurate figures of how much a LA vs a Li system would cost me and how long I'd expect it to last.

 

 

One thing that I probably should also mention is that we only expect to keep our boat 4-5 years before we upgrade. So batteries that last a thousand years are a bit wasted on us. So when I'm calculating the cost of LAs vs Lis, I really need to amortise over 5 years - it doesn't help me much if Li's save me money over 20 years. Of course the next owners would appreciate them I'm sure, and that might add a bit of value to the sale price of the boat, but if I was buying a boat I wouldn't put much stock in the quality of the batteries they had on board because you'd have no idea if they had been abused.

I guess what a lot of it comes down to is that I'm not sure it's wise to invest in something fragile - and if you are comparing the cost of LAs and Li's over many years then what you are doing is comparing an investment.

On my last boat I fitted cheap leisure batteries before I sold it and took the expensive tractions with me for my new boat 

[MtB]

2 hours ago, ivan&alice said:

Of course the next owners would appreciate them I'm sure, and that might add a bit of value to the sale price of the boat,

 

I'd have thought the opposite.

 

Most boat buyers, especially those who feel the need for a survey (i.e. almost all of them) are not technically savvy and would (correctly) see Li batts as unnecessarily complicated and incomprehensible, and therefore quite a drawback and a reason NOT to buy the boat. 

[Dr Bob]

4 hours ago, ivan&alice said:

 

I think there have been a number of good points made but none so far that (to me) justify the cost of Li's. I think I probably need to get some much more accurate figures of how much a LA vs a Li system would cost me and how long I'd expect it to last.

 

 

 

Ivan, I would repeat what I said on the first page on post 18.

"Dont even think about Li's if you are not prepared to do a diy BMS"

Nothing you have said since would convince me that you are ready for Li's. You should be asking far more technical questions on whether it is possible for you...and particulary about how the Li's will work with your charging sources, particularly your alternator.

 

On cost benefit...for the 'average' CC'er or CM'er, Li's will be cheaper over a 5 or 6 year cycle where 2 changes of LA's are needed and extra diesel cost is factored in. The problem here is that you will not be an average boater if you put 1000Ahrs LA capacity and 1500KW of panels. In your case you dont need Li's as you will get by with LA's ...but you will still run your engine more than I will in winter.

 

My concern over your plan is that 1500KW of solar on the roof is just not practical......how are you getting off the roof in a lock or do you stay on the boat all the time?

[Alan de Enfield]

8 minutes ago, Dr Bob said:

how are you getting off the roof in a lock or do you stay on the boat all the time?

……………….. It is the Butler following behind in the Rolls wot does it.

[MtB]

1 hour ago, Dr Bob said:

My concern over your plan is that 1500KW of solar on the roof is just not practical......

 

I agree. 1.5 mW of panels is solar farm territory!!

 

[rusty69]

6 minutes ago, Mike the Boilerman said:

 

I agree. 1.5 mW of panels is solar farm territory!!

 

Can you get milliwatt panels these days too?It would be a very small solar farm.

[MtB]

6 minutes ago, rusty69 said:

Can you get milliwatt panels these days too?It would be a very small solar farm.

 

Oh do I mean MW?!!

 

Mebbe Dr Bob can clarify....

 

 

[rusty69]

8 minutes ago, Mike the Boilerman said:

Oh do I mean MW?!!

I dunno.I only listen to FM and internet radio these daisies.

 

9 minutes ago, Mike the Boilerman said:

Mebbe Dr Bob can clarify....

No need to butter him up.

[Dr Bob]

20 minutes ago, rusty69 said:

I dunno.I only listen to FM and internet radio these daisies.

 

No need to butter him up.

Butter, Farms, we will be onto lettuce soon.

30 minutes ago, Mike the Boilerman said:

 

Oh do I mean MW?!!

 

Mebbe Dr Bob can clarify....

 

 

Lettuce think about that one.

[rusty69]

28 minutes ago, Dr Bob said:

Lettuce think about that one.

I've bin thinking. An ant farm is the most likely place that would have a small solar farm.They wouldn't use milliwatts anyway, probably ants per hour.I am adamant about that (no, not the 80's pop singer).

[Dr Bob]

11 minutes ago, rusty69 said:

I've bin thinking.

Now dont go overdoing it!

 

11 minutes ago, rusty69 said:

IAn ant farm is the most likely place that would have a small solar farm.They wouldn't use milliwatts anyway, probably ants per hour.I am adamant about that (no, not the 80's pop singer).

What is an ant going to do with all that electrickery?

[rusty69]

22 minutes ago, Dr Bob said:

Now dont go overdoing it!

 

What is an ant going to do with all that electrickery?

Store it in Ant-acid Bat-Trees.

 

(obviously with permission from the bats).

Edited October 4, 2019 by rusty69

[Dr Bob]

29 minutes ago, rusty69 said:

Store it in Ant-acid Bat-Trees.

 

(obviously with permission from the bats).

Nah, ants are far too clever for that. They will be using Lithiums.

 

.

.

.

.

.

There, back on topic!

[WotEver]

1 hour ago, Mike the Boilerman said:

Oh do I mean MW?!!

Yup

[jetzi]

On 04/10/2019 at 13:04, Dr Bob said:

"Dont even think about Li's if you are not prepared to do a diy BMS"
Nothing you have said since would convince me that you are ready for Li's. You should be asking far more technical questions on whether it is possible for you...and particulary about how the Li's will work with your charging sources, particularly your alternator.

I have no doubt that I am not ready for Li's (or LAs for that matter!) I am beginning to look into the options so it seems reasonable that I don't know what I'm talking about yet. As I say, I have an April install date so I have several months to think about it and ask other questions. I personally find that the forum is more interesting and useful on those occassions that it stays on topic (some don't and fine, each to his own). The topic of this thread is whether the benefits of installing Li are mitigated by instead investing in a lot of relatively cheap solar to charge your LAs. And I think there have been a number of good counterpoints to that thread.

 

Thanks for the hint that I'll need to DIY a BMS to make Li's cost effective. I haven't forgotten and I'm bearing it in mind.
 

On 04/10/2019 at 13:04, Dr Bob said:

The problem here is that you will not be an average boater if you put 1000Ahrs LA capacity and 1500KW of panels. In your case you dont need Li's as you will get by with LA's ...but you will still run your engine more than I will in winter.

I'm not sure if I see this as a problem, rather a solution. My proposed solution to having enough electricity, to not having to charge my batteries as often, and to keeping costs low, is to have a larger than average bank of batteries and a larger than average solar array. Another possible solution is to have an average solar array and an average battery capacity, but to make them Li's. I haven't done the sums properly because I haven't really specced out the two options and costed them properly yet, but at first glance it seems that the big solar & LA solution will suit my needs better for less money. And it's quite possible I'm wrong which is why I proposed the hypothesis to hear some debate on this one particular point. Yes we could get into the virtues of building your own BMS and how long a life you can expect from your batteries and so on, but I prefer to clear up one question at a time - and the question is can you increase your solar generation to such a degree that the advantages of Li over LA lessen and no longer justify the cost? We've had four good arguments but not dealbreakers, and I still reckon yes, but I'm very open to being convinced otherwise.

 

On 04/10/2019 at 13:04, Dr Bob said:

My concern over your plan is that 1500KW of solar on the roof is just not practical......how are you getting off the roof in a lock or do you stay on the boat all the time?

I envisage 4 solar panels which would be around 1m x 6.6m for 1500W. Mounted centrally this would give me 30 odd cm either side of the panel for a walkway (more if I hinged them up on one side, and more than 10 metres of roof still walkable. I'm not completely sure why 1500W seems like such a ludicrous amount.

 

I'm not really understanding the question, it might be that I'm locking incorrectly. What I normally do is:

1. Moor up on the lock landing and set the lock as needed.
2. Board the boat and slowly drive it into the lock. Stop it with reverse and get the aft deck near the ladder if possible.
3. If I'm going up, climb up the ladder which I find is usually conveniently located towards one end or the other of the boat, requiring at most a metre of shimmying along the gunwale or edge of the roof to reach it. Alternatively if the lock isn't too deep or I'm going down, I can just step off or climb straight up onto the wall from the very edge of the roof.
4. Now that I'm off the boat, loosely tie the boat by the midline to the centre bollard.
5. Close gates. Fill/empty the lock. Close the paddles. Open the other gates.
6. Either climb back down the ladder or step onto the edge of the roof.
7. Drive the boat out and tie the boat up on the lock landing.
8. Close gates and make sure paddles are all closed.
9. Drive off.

Of course, if I'm not single handed, which I'm not most of the time, my boatmate can get off in Step 1 and I can just stay on the boat until they rejoin at step 9.

 

So I can only really imagine needing to walk along the roof at Step 3, if I am singlehanded and the ladder happens to be in an unusually awkward position. Even so, I could probably shimmy along the gunwale if I don't think there is a chance of being squished between the lock wall and the boat.

At what point are all of you pacing up and down the boat roof while locking?

[MtB]

33 minutes ago, ivan&alice said:

So I can only really imagine needing to walk along the roof at Step 3, if I am singlehanded and the ladder happens to be in an unusually awkward position.

 

I on the other hand need to get on the roof at EVERY lock.

 

To analyse the difference, it is because I am single handing, my boat is almost full length and trad stern so no option to shuffle up or down the length of the lock to get near a ladder.

 

 

 

[peterboat]

1 hour ago, ivan&alice said:

I have no doubt that I am not ready for Li's (or LAs for that matter!) I am beginning to look into the options so it seems reasonable that I don't know what I'm talking about yet. As I say, I have an April install date so I have several months to think about it and ask other questions. I personally find that the forum is more interesting and useful on those occassions that it stays on topic (some don't and fine, each to his own). The topic of this thread is whether the benefits of installing Li are mitigated by instead investing in a lot of relatively cheap solar to charge your LAs. And I think there have been a number of good counterpoints to that thread.

 

Thanks for the hint that I'll need to DIY a BMS to make Li's cost effective. I haven't forgotten and I'm bearing it in mind.
 

I'm not sure if I see this as a problem, rather a solution. My proposed solution to having enough electricity, to not having to charge my batteries as often, and to keeping costs low, is to have a larger than average bank of batteries and a larger than average solar array. Another possible solution is to have an average solar array and an average battery capacity, but to make them Li's. I haven't done the sums properly because I haven't really specced out the two options and costed them properly yet, but at first glance it seems that the big solar & LA solution will suit my needs better for less money. And it's quite possible I'm wrong which is why I proposed the hypothesis to hear some debate on this one particular point. Yes we could get into the virtues of building your own BMS and how long a life you can expect from your batteries and so on, but I prefer to clear up one question at a time - and the question is can you increase your solar generation to such a degree that the advantages of Li over LA lessen and no longer justify the cost? We've had four good arguments but not dealbreakers, and I still reckon yes, but I'm very open to being convinced otherwise.

 

I envisage 4 solar panels which would be around 1m x 6.6m for 1500W. Mounted centrally this would give me 30 odd cm either side of the panel for a walkway (more if I hinged them up on one side, and more than 10 metres of roof still walkable. I'm not completely sure why 1500W seems like such a ludicrous amount.

 

I'm not really understanding the question, it might be that I'm locking incorrectly. What I normally do is:

1. Moor up on the lock landing and set the lock as needed.
2. Board the boat and slowly drive it into the lock. Stop it with reverse and get the aft deck near the ladder if possible.
3. If I'm going up, climb up the ladder which I find is usually conveniently located towards one end or the other of the boat, requiring at most a metre of shimmying along the gunwale or edge of the roof to reach it. Alternatively if the lock isn't too deep or I'm going down, I can just step off or climb straight up onto the wall from the very edge of the roof.
4. Now that I'm off the boat, loosely tie the boat by the midline to the centre bollard.
5. Close gates. Fill/empty the lock. Close the paddles. Open the other gates.
6. Either climb back down the ladder or step onto the edge of the roof.
7. Drive the boat out and tie the boat up on the lock landing.
8. Close gates and make sure paddles are all closed.
9. Drive off.

Of course, if I'm not single handed, which I'm not most of the time, my boatmate can get off in Step 1 and I can just stay on the boat until they rejoin at step 9.

 

So I can only really imagine needing to walk along the roof at Step 3, if I am singlehanded and the ladder happens to be in an unusually awkward position. Even so, I could probably shimmy along the gunwale if I don't think there is a chance of being squished between the lock wall and the boat.

At what point are all of you pacing up and down the boat roof while locking?

I had full traction batteries which is the next step up from Trojans while they lasted well it's still the same old problems in winter, you need to get them up to 100% twice a week to give them a long life. That unfortunately can be expensive in fuel  and time, and believe me your 1500 watts of solar isn't enough! I have way over double that and will have treble that shortly and that's just enough for a winter. Whilst I am a heavy user of power and I am also on the boat all day so if you arnt you will have an average chance of doing it

[PeterF]

4 hours ago, ivan&alice said:

I envisage 4 solar panels which would be around 1m x 6.6m for 1500W. Mounted centrally this would give me 30 odd cm either side of the panel for a walkway (more if I hinged them up on one side, and more than 10 metres of roof still walkable. I'm not completely sure why 1500W seems like such a ludicrous amount.

I thought that 360 to 375W solar panels are about 1m x 2m so you will need 8m total length. Suggest you check this because if you are limited to 6.6m then you may have an issue with one of your base assumptions. However, if you have found some panels with a much higher yield per square meter let me know.

 

The recently publicised Mothership Marine 57ft Narrowboat "Shine" was almost completely covered in solar panels and that was 1.8kW.

Edited October 6, 2019 by PeterF
Spelling

[Sea Dog]

2 hours ago, Mike the Boilerman said:

 

I on the other hand need to get on the roof at EVERY lock.

 

 

 

 

 

Yes and, furthermore, I'd suggest everyone who stays on the boat in a lock may have to traverse the roof in the event of an emergency as that's frequently the only way to a ladder. 

 

Its no good saying that the panels would be sacrificed in an emergency, because the imperative to get up the ladder quickly may come at any time and delay whilst the steerer is wondering whether the situation is bad enough to warrant walking over the solar (and is that even a safe proposition?) could be the delay that turns a drama into a crisis.

[Dr Bob]

3 hours ago, ivan&alice said:

At what point are all of you pacing up and down the boat roof while locking?

There are usually 2 of us on the boat when locking.

Going up.

Mrs Bob sets the lock while I hold the boat on the lock landing.

I drive it in the lock. Mrs Bob shuts the gates.

She then walks on to set the next lock in the flight.

I climb on the roof, across the roof and up the ladder.

I raise the paddles/open gate/get boat out/close gates

I drive into the next lock and repeat.

 

If I couldnt walk on the roof it would be a right pain.