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Batteries in yer boats


AllenTC2

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Well, as you all have dashed all hopes of me having a multi-year float extravaganza (just kidding, I DO appreciate the reality check LOL) I have taken to telling my US RVing brethren and sistren about narrowboats. Needless to say many comparisons were made. One oft heard comment was "Well, we have endless miles of road compared to their 2,200 miles of canal". Despite the fact that our roads are indeed finite, I pointed out our roads are also full of idiot drivers texting while (whilst?) speeding and applying makeup or whatever. Even if you're totally preoccupied with your cup of tea, how much trouble can you cause at a max speed of 4 mph?

Don't answer that, I'm sure you all have some epic 'idiot boater' stories.

ANYWAY.....so batteries came up. Over here, AGM are fairly common. But coming up rapidly are these LiFePO4 batteries. They are lighter weight (which I don't imagine is a big concern for boaters?), are hard to kill (can be used down to something like 20% of their capacity), don't gradually decline in the juice they deliver.....big downside for them at the moment is cost (I have 2 300ah LiFEPO4s, each was about $2,500USD, about 33% of my whole solar install) and the fact they are temperature sensitive and need to be in an enclosed bay (thus losing some precious cargo space).

Just curious as to how your energy needs are met when you're not on shore power (which now that I think of it, is also funny....that's what we call it when our land-locked vehicles are plugged up at a campground).

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8 minutes ago, AllenTC2 said:

Well, as you all have dashed all hopes of me having a multi-year float extravaganza (just kidding, I DO appreciate the reality check LOL) I have taken to telling my US RVing brethren and sistren about narrowboats. Needless to say many comparisons were made. One oft heard comment was "Well, we have endless miles of road compared to their 2,200 miles of canal". Despite the fact that our roads are indeed finite, I pointed out our roads are also full of idiot drivers texting while (whilst?) speeding and applying makeup or whatever. Even if you're totally preoccupied with your cup of tea, how much trouble can you cause at a max speed of 4 mph?

Don't answer that, I'm sure you all have some epic 'idiot boater' stories.

ANYWAY.....so batteries came up. Over here, AGM are fairly common. But coming up rapidly are these LiFePO4 batteries. They are lighter weight (which I don't imagine is a big concern for boaters?), are hard to kill (can be used down to something like 20% of their capacity), don't gradually decline in the juice they deliver.....big downside for them at the moment is cost (I have 2 300ah LiFEPO4s, each was about $2,500USD, about 33% of my whole solar install) and the fact they are temperature sensitive and need to be in an enclosed bay (thus losing some precious cargo space).

Just curious as to how your energy needs are met when you're not on shore power (which now that I think of it, is also funny....that's what we call it when our land-locked vehicles are plugged up at a campground).

The LiFePO4s also need close and accurate control of charge - unlike lead acids that just need adequate charging voltage and enough time.

 

At present a few pioneers are running LiFePO4 systems with either a home brew or expensive commercial control system, often I suspect second hand batteries from bus and car traction systems.

 

We do have AGM and other forms of sealed lead acid batteries but in my view the drawback with them is they are very difficult for the average boater to diagnose  where as open lead acid batteries are easy (access willing!). I get by perfectly well with 330Ah of one of the "better" makes of open cell lead acid batteries and 160 watts of solar but then I don't live aboard fr long periods during the winter and am probably a fairly light user of electricity by today's standards. Open lead acid batteies are in my view the best value for money and easiest to use and look after at present.

 

 

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11 minutes ago, Tony Brooks said:

The LiFePO4s also need close and accurate control of charge - unlike lead acids that just need adequate charging voltage and enough time.

 

At present a few pioneers are running LiFePO4 systems with either a home brew or expensive commercial control system, often I suspect second hand batteries from bus and car traction systems.

I cant imagine paying £1200 for a 100Ah battery, but Sterling are selling these which say they have an inbuilt BMS:

 

https://sterling-power.com/products/lithium-batteries?_pos=1&_sid=8012b349e&_ss=r&variant=50393785109

 

Does this mean that, as long as you set the correct charging voltages, (14.8V Max, 14.6V Recommended, 13.8V float), does the built in BMS protect the battery, and make things much simpler?

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There are a couple of companies in your part of the world that make rather nice batteries, US and Trojan. The Trojan 6volt lead-acids are popular with liveaboard boaters.

 

..............Dave

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Yes Trojan golf-cart batteries are a good compromise between “leisure batteries” which truly awful, and LiFePO4s which are great but expensive and need a purpose-designed charging system. For Narrowboats, one of the advantages of LiFePO4s - being half the weight- is not relevant. But the ability to charge rapidly and to be unaffected by being left partially charged, is a great advantage for people who like to tie up for a few days. For people who tend to cruise every day, that is another non-applicable advantage.

 

AGM are another alternative, but I think Trojan or US semi-traction batteries are better value. The most popular are T105s or the US equivalent, because they offer the best value (cost per watt-hour) due, I suspect, to the volumes made and sold.

 

Edited by nicknorman
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1 hour ago, Richard10002 said:

I cant imagine paying £1200 for a 100Ah battery, but Sterling are selling these which say they have an inbuilt BMS:

 

https://sterling-power.com/products/lithium-batteries?_pos=1&_sid=8012b349e&_ss=r&variant=50393785109

 

Does this mean that, as long as you set the correct charging voltages, (14.8V Max, 14.6V Recommended, 13.8V float), does the built in BMS protect the battery, and make things much simpler?

It should but who knows. I can buy a awful lot of lead acids for that sort of money and so far there has not been long enough experience to persuade me they are cost effective or easy to diagnose.

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1 hour ago, Richard10002 said:

I cant imagine paying £1200 for a 100Ah battery, but Sterling are selling these which say they have an inbuilt BMS:

 

https://sterling-power.com/products/lithium-batteries?_pos=1&_sid=8012b349e&_ss=r&variant=50393785109

 

Does this mean that, as long as you set the correct charging voltages, (14.8V Max, 14.6V Recommended, 13.8V float), does the built in BMS protect the battery, and make things much simpler?

But if you are charging from an engine not a battery charger what are you going to do with the output from the alternator. I know one boat that has a VSR to connect to the bowthruster batteries, but then the Lithiums hold the voltage up so the VSR doesn't drop straight out when the engine stops.

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I pay 400 quids for 4 sealed lead acid batteries that are in use every day of the year as a full time liveaboard. I have done things this way for thirty years although only went sealed type about ten years ago. Sometimes plugged in to mains but often not over the years. they last a minimum of two years, present ones two and a half years old, fully mains boat. Life is too short to worry about batteries, best treat them as a consumable same as diesel.

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2 minutes ago, Sea Dog said:

I'm on sealed lead acid again after my first set lasted 7 years, for similar reasons to the disposable theory championed by @mrsmelly  Next time around I'll be looking closely at Lead Carbon which promise to run Lithiums a pretty close race without the charging system modufications.

Regrettably some on here have a long enough memory to be wary about the promises made about lead carbon batteries about 20 years or so ago so may be sceptical.

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Just now, Tony Brooks said:

Regrettably some on here have a long enough memory to be wary about the promises made about lead carbon batteries about 20 years or so ago so may be sceptical.

Fair enough!  The latest offerings aren't a recent perfection of an older idea then?

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I'm one of those with LiFePo4s.

Best thing I have bought for the boat other than 2 wheelbarrow wheels from Aldi for 7 squid each and our ecofan (......I mustn't mention its broken).

No, the LiFePo4s are great. Much less engine running compared with what I would need for LA's.

If you buy new ones then they are NEVER going to be cost effective. If you buy 2nd hand ones from old electric vehicles then they are a similar cost over a 5 year period. Mine were a 3rd of the price of new ones.

 

1 hour ago, Richard10002 said:

I cant imagine paying £1200 for a 100Ah battery, but Sterling are selling these which say they have an inbuilt BMS:

 

https://sterling-power.com/products/lithium-batteries?_pos=1&_sid=8012b349e&_ss=r&variant=50393785109

 

Does this mean that, as long as you set the correct charging voltages, (14.8V Max, 14.6V Recommended, 13.8V float), does the built in BMS protect the battery, and make things much simpler?

There are 2 problems with these 'drop' in batteries.

1) They are likely to have some sort of isolation if voltages or temps get too high or low. If you read the info on the cruiser forum (for lumpy water boats) they have been using LiFePo4s for 10 years or so and have lots of experience. Most of these 'drop in' LiFePo4's only have small current handling isolation switches so will not be able to handle the 160A that might be being taken out or put in. Some of the 'inferior' chinese cheap designs have much smaller capacity switches.

2) As said above, equally important to protecting the battery from over or under charge via the isolation switches, is to protect your alternator. It is not going to last long if the 'drop in' battery is going to isolate itself from the charge sources when it gets to its 'high level' voltage and the alternator is banging in 60A. Those electrons have to go somewhere.

 

If the Op wants to know more about the use of LiFePo4s on canal boats, then just do a search here. There are 4 of us with them and would never go back.

 

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3 minutes ago, Dr Bob said:

I'm one of those with LiFePo4s.

Best thing I have bought for the boat other than 2 wheelbarrow wheels from Aldi for 7 squid each and our ecofan (......I mustn't mention its broken).

No, the LiFePo4s are great. Much less engine running compared with what I would need for LA's.

If you buy new ones then they are NEVER going to be cost effective. If you buy 2nd hand ones from old electric vehicles then they are a similar cost over a 5 year period. Mine were a 3rd of the price of new ones.

 

There are 2 problems with these 'drop' in batteries.

1) They are likely to have some sort of isolation if voltages or temps get too high or low. If you read the info on the cruiser forum (for lumpy water boats) they have been using LiFePo4s for 10 years or so and have lots of experience. Most of these 'drop in' LiFePo4's only have small current handling isolation switches so will not be able to handle the 160A that might be being taken out or put in. Some of the 'inferior' chinese cheap designs have much smaller capacity switches.

2) As said above, equally important to protecting the battery from over or under charge via the isolation switches, is to protect your alternator. It is not going to last long if the 'drop in' battery is going to isolate itself from the charge sources when it gets to its 'high level' voltage and the alternator is banging in 60A. Those electrons have to go somewhere.

 

If the Op wants to know more about the use of LiFePo4s on canal boats, then just do a search here. There are 4 of us with them and would never go back.

 

If I was younger I would look into it but if my Trojans do as well (I am hoping better) than the last set then they should see me out boating wise.

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2 hours ago, Richard10002 said:

 (14.8V Max, 14.6V Recommended, 13.8V float),

You cannot 'float' an LiFePo4 at 13.8V.

It will kill it.

You do not float LiFePo4s.

Anyone who gets LiFePo4s has to forget everything they learnt about LA's. The fact that Sterling use a float voltage says to me that they do not understand Li's so why would anyone buy an LiFePo4 battery from them?

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15 minutes ago, Tony Brooks said:

Regrettably some on here have a long enough memory to be wary about the promises made about lead carbon batteries about 20 years or so ago so may be sceptical.

Elecsol iirc. I recently bought a motorhome with one still fitted!! 

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3 minutes ago, Dr Bob said:

2) As said above, equally important to protecting the battery from over or under charge via the isolation switches, is to protect your alternator. It is not going to last long if the 'drop in' battery is going to isolate itself from the charge sources when it gets to its 'high level' voltage and the alternator is banging in 60A. Those electrons have to go somewhere.

 

If the Op wants to know more about the use of LiFePo4s on canal boats, then just do a search here. There are 4 of us with them and would never go back.

 

Firstly, and most importantly: Where did you get your batteries from? Is there somewhere like Bimble Solar who buy the used ones and resell them?

 

Secondly: Do alternators "Bang in 60A"? or do batteries just draw what they want? I ask because, with my lead acid batteries, my alternator starts at about 35A, but reduces as time goes by - just like my mains battery charger? I'm guessing that something similar would happen with lithium, but maybe not?

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2 minutes ago, ditchcrawler said:

If I was younger I would look into it but if my Trojans do as well (I am hoping better) than the last set then they should see me out boating wise.

I totally agree with you Brian. If you are happy then why change. We've only had our boat 3 years (and lived on a yot for 3 years) and are just fed up of running the engine in the winter (and summer when under trees). That's why we took the plunge.....and it was spot on for us.

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1 minute ago, mrsmelly said:

Elecsol iirc. I recently bought a motorhome with one still fitted!! 

The early Elecsols were great and relatively inexpensive. I bought a set when they first came out, got almost 5 years of heavy use from them, then bought another set which were equally good. Soon after that the company was bought out by another group who "re-engineered" them into something which was completely rubbish!

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Just now, Keeping Up said:

The early Elecsols were great and relatively inexpensive. I bought a set when they first came out, got almost 5 years of heavy use from them, then bought another set which were equally good. Soon after that the company was bought out by another group who "re-engineered" them into something which was completely rubbish!

This one in fairness was a minimum of 7 years old and had been sat in dry storage flat for four years lol. Thing is I absolutely knew it would be buggered but still charged it up ? It charged up steadily and 48 hours after being taken off charge with no load showed 12.7 volts :D so of course I re fitted it and switched leccy on and one dim light and nowt much else but it still showed 12.7?? Put a spanking new battery on and everything works without fault unsuprisingly lol.

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5 minutes ago, Richard10002 said:

Firstly, and most importantly: Where did you get your batteries from? Is there somewhere like Bimble Solar who buy the used ones and resell them?

 

Richard,

Myself, @MoominPapa and @Tom and Bex got our 2nd hand ones from a guy called Jeremy at a company called Ev-support.

sales@ev-support.co.uk

They were winston Thunderskys. I paid £1000 for a 480ahr 12V bank.

 

5 minutes ago, Richard10002 said:

Secondly: Do alternators "Bang in 60A"? or do batteries just draw what they want? I ask because, with my lead acid batteries, my alternator starts at about 35A, but reduces as time goes by - just like my mains battery charger? I'm guessing that something similar would happen with lithium, but maybe not?

Depends on your alternator!

Ok, I've got a Beta 43 with a not very good 90A domestic alternator. The max voltage it puts out is 13.9v into my LA's. Not enough so when I got the bote 3 years ago, I got a Sterling AtoB (shock horror!!!!!!). It worked great so on the LA setting, I was getting 14.4V (at say 15°C ambient). On start up when LAs were down to 75% SoC, I would get 50A for a few mins which then decayed quickly to 35A and then down to less than 20A an hour later and 6-10A an hour later......pretty typical.

Now with the LiFePo4s, the current I get out of the system (alternator and AtoB) is dependent on the dip switch setting I use on the AtoB. See graph below. I did a 4 hour cruise earlier in the week. Orange line is the current output. After a few mins it drop to high 30'sA and stays there. The sharp drops every 20 mins are the AtoB doing its thing(!). In the first hour, the output is a bit 'ragged' but that is the washing machine on for 45mins. Overall then, after the first few mins, the Amps output is pretty constant at around 38A. This is on the lowest dipswitch setting on the AtoB (ie the US gel setting). I use this one as I am happy with 40A out all the time (while there is still solar around). If I choose the AGM setting on the AtoB then the alternator starts at 60A and then settles down at 50A. I will use this during the winter. The LiFePo4s will take that power all day until they get to 95% charged, but my AtoB shuts off once the voltage gets to 13.7V which is around 80% SoC on my system. Look at the blue line. The voltage during charge is totally different to LA's and you can see from the voltage how well charged you are.

Dont forget though there is another variable and that is alternator temperature. If the temp of the alternator gets above 95°C then it will be cutting back its output. More knowledgable people will advise here. At 40A output I am happy I am not overheating the alternator as i have very little ventilation in my cruiser stern engine bay. At a 50A output it does start getting hot.......shouldnt be a problem in the winter for an hour or two running each day. Next year, I will have more confidence to move the output up to 50A or 60A. I dont think however these 'small frame' alternators are built to run at 60A for hours.

The benefit of taking all the power you can throw at them is when you have 500W of solar. It always takes the max and doesnt cut back on it like my LA's used to do.

Screen Shot 2019-10-18 at 14.44.42.png

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16 minutes ago, Richard10002 said:

Firstly, and most importantly: Where did you get your batteries from? Is there somewhere like Bimble Solar who buy the used ones and resell them?

 

Secondly: Do alternators "Bang in 60A"? or do batteries just draw what they want? I ask because, with my lead acid batteries, my alternator starts at about 35A, but reduces as time goes by - just like my mains battery charger? I'm guessing that something similar would happen with lithium, but maybe not?

Richard my LifePo4s came from a transit van, it didnt have many cycles on them, they are Valence U27s a really good American battery with internal BMS which I can read with the laptop. I only use solar to charge my batteries, for most of the year, I have a whispergen for backup and fast heating, its hard to explain how good LifePo4s are in comparison to all other batteries, but this maybe will help you.

I have an Aixam electric truck it normally has 12 x 12 volt 80 ah gel batteries, they are connected to give 48 volts, this when new gives a range between 40 - 60 miles. I now have in it 4 x 12 volt 138 ah LifePo4 batteries they can deliver the same range as the much bigger bank of Gel batteries, also the acceleration is superior and it goes 5 mph faster! I charge these batteries with 900 watts of solar on the roof of it and it is working very well, The problem with the original batteries is how long they last most users say a couple of years tops the LAs they had before these were even worse. If people had fitted solar to their Gel batteries it might have extended their lives because they were fully charged more often? but I doubt if it would have helped much beyond maybe an extra year? I would expect my LifePo4s to last the life of the van because they arnt that bothered about being left with only 20% charge in them. Hope this helps

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12 minutes ago, Dr Bob said:

Richard,

Myself, @MoominPapa and @Tom and Bex got our 2nd hand ones from a guy called Jeremy at a company called Ev-support.

sales@ev-support.co.uk

They were winston Thunderskys. I paid £1000 for a 480ahr 12V bank.

 

Depends on your alternator!

Ok, I've got a Beta 43 with a not very good 90A domestic alternator. The max voltage it puts out is 13.9v into my LA's. Not enough so when I got the bote 3 years ago, I got a Sterling AtoB (shock horror!!!!!!). It worked great so on the LA setting, I was getting 14.4V (at say 15°C ambient). On start up when LAs were down to 75% SoC, I would get 50A for a few mins which then decayed quickly to 35A and then down to less than 20A an hour later and 6-10A an hour later......pretty typical.

Now with the LiFePo4s, the current I get out of the system (alternator and AtoB) is dependent on the dip switch setting I use on the AtoB. See graph below. I did a 4 hour cruise earlier in the week. Orange line is the current output. After a few mins it drop to high 30'sA and stays there. The sharp drops every 20 mins are the AtoB doing its thing(!). In the first hour, the output is a bit 'ragged' but that is the washing machine on for 45mins. Overall then, after the first few mins, the Amps output is pretty constant at around 38A. This is on the lowest dipswitch setting on the AtoB (ie the US gel setting). I use this one as I am happy with 40A out all the time (while there is still solar around). If I choose the AGM setting on the AtoB then the alternator starts at 60A and then settles down at 50A. I will use this during the winter. The LiFePo4s will take that power all day until they get to 95% charged, but my AtoB shuts off once the voltage gets to 13.7V which is around 80% SoC on my system. Look at the blue line. The voltage during charge is totally different to LA's and you can see from the voltage how well charged you are.

Dont forget though there is another variable and that is alternator temperature. If the temp of the alternator gets above 95°C then it will be cutting back its output. More knowledgable people will advise here. At 40A output I am happy I am not overheating the alternator as i have very little ventilation in my cruiser stern engine bay. At a 50A output it does start getting hot.......shouldnt be a problem in the winter for an hour or two running each day. Next year, I will have more confidence to move the output up to 50A or 60A. I dont think however these 'small frame' alternators are built to run at 60A for hours.

The benefit of taking all the power you can throw at them is when you have 500W of solar. It always takes the max and doesnt cut back on it like my LA's used to do.

Screen Shot 2019-10-18 at 14.44.42.png

And when they are fully charged where does the output from the alternator go, or does the a to b take care of that?

 

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5 minutes ago, ditchcrawler said:

And when they are fully charged where does the output from the alternator go, or does the a to b take care of that?

 

Our 'normal' operation is that they never get to 100%.

We are usually 40-80% so never get near full.

On the few days this summer when doing more than 4 hours per day, the AtoB has gone into 'float' at around 13.7V which is 80-90% ish charged.........but 'float' actually means the Amps output are cut back to a low leverl (5A ish). If I set the AtoB at the AGM setting then maybe the cut off would be 14.0V which is too high for me so I will only use this in the winter when charging on a mooring. Everyone's system will be different. The AtoB seems to be an excellent way to control the alternators output to the LiFePo4s.

IF something went wrong and the voltage did rise too much, then I have audible alarms at 13.7V and an auto disconnect at 13.8V which isolates the Li bank. As the Li bank is paralled in with my remaining LA's (others just use their engine start LA) then the alternator current would just go into the LAs. My auto disconnect has never activated in the 6 months I have had them, other than the few tests I have run to check the 'emergency' cut off.

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