fudd Posted November 23, 2020 Report Share Posted November 23, 2020 Hello. Further to my charger thread, would I be better off with smaller batteries to build a 1000ah bank or fewer larger cells? I’m looking at Winston cells. Thank you. Link to comment Share on other sites More sharing options...
IanD Posted November 23, 2020 Report Share Posted November 23, 2020 3 minutes ago, fudd said: Hello. Further to my charger thread, would I be better off with smaller batteries to build a 1000ah bank or fewer larger cells? I’m looking at Winston cells. Thank you. I assume you're aware of all the issues about assembling your own lithium bank and BMS? If not -- or even if you are -- I suggest you read this, it's long and a bit US/yacht biased but there's a *huge* amount of useful information in it: https://marinehowto.com/lifepo4-batteries-on-boats/ Link to comment Share on other sites More sharing options...
fudd Posted November 23, 2020 Author Report Share Posted November 23, 2020 3 hours ago, IanD said: I assume you're aware of all the issues about assembling your own lithium bank and BMS? If not -- or even if you are -- I suggest you read this, it's long and a bit US/yacht biased but there's a *huge* amount of useful information in it: https://marinehowto.com/lifepo4-batteries-on-boats/ 3 hours ago, IanD said: I assume you're aware of all the issues about assembling your own lithium bank and BMS? If not -- or even if you are -- I suggest you read this, it's long and a bit US/yacht biased but there's a *huge* amount of useful information in it: https://marinehowto.com/lifepo4-batteries-on-boats/ Fascinating read Ian. I’m only halfway through but have learnt quite a lot. Might take a few ‘reads’ before I ingest most of it. Thanks. Link to comment Share on other sites More sharing options...
wandering snail Posted November 24, 2020 Report Share Posted November 24, 2020 22 hours ago, fudd said: Fascinating read Ian. I’m only halfway through but have learnt quite a lot. Might take a few ‘reads’ before I ingest most of it. Thanks. Scary read! What do you think, Moominpapa? Link to comment Share on other sites More sharing options...
MoominPapa Posted November 24, 2020 Report Share Posted November 24, 2020 28 minutes ago, wandering snail said: Scary read! What do you think, Moominpapa? Marinehowto and Nordkyn Design were my bibles when I was designing the installation on Melaleuca. I fear that too many people are jumping on this bandwagon with a "How hard can it be?" attitude and will likely get burned. Let's hope, not literally. MP. 1 Link to comment Share on other sites More sharing options...
fudd Posted November 25, 2020 Author Report Share Posted November 25, 2020 15 hours ago, MoominPapa said: Marinehowto and Nordkyn Design were my bibles when I was designing the installation on Melaleuca. I fear that too many people are jumping on this bandwagon with a "How hard can it be?" attitude and will likely get burned. Let's hope, not literally. MP. I’ve been researching this subject for six months and I won’t be making any decisions for at least another year. From what I have read so far is that the installation will be far more complicated for me to deal with. I will be seeking professional advice. Link to comment Share on other sites More sharing options...
Jen-in-Wellies Posted November 25, 2020 Report Share Posted November 25, 2020 (edited) 20 minutes ago, fudd said: I’ve been researching this subject for six months and I won’t be making any decisions for at least another year. From what I have read so far is that the installation will be far more complicated for me to deal with. I will be seeking professional advice. Pick your professional with care. At this stage, I expect most professional boat electricians know less than the most knowledgable boaters who have fitted them. A bit like asking an 18th century universtiy trained medical doctor for advice on an illness. The best you could hope for is that they wouldn't make you any worse! Edited November 25, 2020 by Jen-in-Wellies 3 Link to comment Share on other sites More sharing options...
mrsmelly Posted November 25, 2020 Report Share Posted November 25, 2020 22 minutes ago, fudd said: I’ve been researching this subject for six months and I won’t be making any decisions for at least another year. From what I have read so far is that the installation will be far more complicated for me to deal with. I will be seeking professional advice. Tried and tested, safe, easy to instal, cheap, do a good job and did I say cheap? Link to comment Share on other sites More sharing options...
fudd Posted November 25, 2020 Author Report Share Posted November 25, 2020 4 hours ago, mrsmelly said: Tried and tested, safe, easy to instal, cheap, do a good job and did I say cheap? Ah, but how many would I need to drive my boat? 4 hours ago, Jen-in-Wellies said: Pick your professional with care. At this stage, I expect most professional boat electricians know less than the most knowledgable boaters who have fitted them. A bit like asking an 18th century universtiy trained medical doctor for advice on an illness. The best you could hope for is that they wouldn't make you any worse! I agree and I will. Thank you. Link to comment Share on other sites More sharing options...
mrsmelly Posted November 25, 2020 Report Share Posted November 25, 2020 46 minutes ago, fudd said: Ah, but how many would I need to drive my boat? I agree and I will. Thank you. Link to comment Share on other sites More sharing options...
alistair1537 Posted November 25, 2020 Report Share Posted November 25, 2020 A thousand Amp hours is a shed load of power? Are you sure you need that much? What is the voltage going to be on this system please? I am also thinking about an electric barge...my next boat. Link to comment Share on other sites More sharing options...
TheBiscuits Posted November 25, 2020 Report Share Posted November 25, 2020 (edited) 9 minutes ago, alistair1537 said: A thousand Amp hours is a shed load of power? Are you sure you need that much? 1000 Amp Hours at 12V nominal is 12kWh - or slightly less than the practical useable power in a gallon of diesel ... Edited November 25, 2020 by TheBiscuits 1 Link to comment Share on other sites More sharing options...
alistair1537 Posted November 25, 2020 Report Share Posted November 25, 2020 1 minute ago, TheBiscuits said: 1000 Amp Hours at 12V nominal is 12kWh - or slighly less than the practical useable power in a gallon of diesel ... I think fudd is doing 1000A/h at 48V - so 4 gallons of diesel then? How many hours cruising can you do on 4 gallons? Link to comment Share on other sites More sharing options...
mrsmelly Posted November 25, 2020 Report Share Posted November 25, 2020 8 minutes ago, alistair1537 said: I think fudd is doing 1000A/h at 48V - so 4 gallons of diesel then? How many hours cruising can you do on 4 gallons? Probably about 4 hours of cruising but what do you then do to put the charge back into the flat batteries? I have a good idea, maybe an internal combustion engined charger? The sun today wouldnt warm a cup of water up. Link to comment Share on other sites More sharing options...
TheBiscuits Posted November 25, 2020 Report Share Posted November 25, 2020 Just now, mrsmelly said: Probably about 4 hours of cruising More like 15-20 hours I'd have said. Litre an hour not gallon an hour for most narowboats. @Alan de Enfield and @Naughty Cal don't get that though! 1 Link to comment Share on other sites More sharing options...
mrsmelly Posted November 25, 2020 Report Share Posted November 25, 2020 1 minute ago, TheBiscuits said: More like 15-20 hours I'd have said. Litre an hour not gallon an hour for most narowboats. @Alan de Enfield and @Naughty Cal don't get that though! You are of course correct, itll be fine then if its blazing sunshine day after tomorrow for a month ? Link to comment Share on other sites More sharing options...
Alan de Enfield Posted November 25, 2020 Report Share Posted November 25, 2020 13 minutes ago, TheBiscuits said: More like 15-20 hours I'd have said. Litre an hour not gallon an hour for most narowboats. @Alan de Enfield and @Naughty Cal don't get that though! Current boat is 10 litres per hour at 5-6knts A previous boat was 1.25 MILES per GALLON at 20-22 Knts Link to comment Share on other sites More sharing options...
alistair1537 Posted November 25, 2020 Report Share Posted November 25, 2020 42 minutes ago, mrsmelly said: You are of course correct, itll be fine then if its blazing sunshine day after tomorrow for a month ? I'd imagine most boats are moored up for winter? Link to comment Share on other sites More sharing options...
mrsmelly Posted November 25, 2020 Report Share Posted November 25, 2020 7 minutes ago, alistair1537 said: I'd imagine most boats are moored up for winter? Probably but still plenty on the move past me today. Link to comment Share on other sites More sharing options...
alistair1537 Posted November 25, 2020 Report Share Posted November 25, 2020 Just now, mrsmelly said: Probably but still plenty on the move past me today. Ah those will be the internal combustion type then...Things might have to slow down a bit more if they move us to solar power - like cruise for a day - moor up for 3 days to recharge...and no cruising in winter. I could live like that. 1 Link to comment Share on other sites More sharing options...
mrsmelly Posted November 25, 2020 Report Share Posted November 25, 2020 2 minutes ago, alistair1537 said: Ah those will be the internal combustion type then...Things might have to slow down a bit more if they move us to solar power - like cruise for a day - moor up for 3 days to recharge...and no cruising in winter. I could live like that. Luckily that nonsense will not come into play for me at my age. I can still boat properly as it won't happen for many years yet Link to comment Share on other sites More sharing options...
Ronaldo47 Posted November 26, 2020 Report Share Posted November 26, 2020 And of course a cold battery delivers less power than a warm one, although drawing a high current should warm up the battery. A technician I used to know who had served with the Royal Signals during the war told me that in the depths of winter, before tryng to start the engine of a tank, it was the practice to briefly put a dead short across the battery with a very large spanner to warm the battery up. Admittedly an electric boat does not needs a heavy cranking starting current like a petrol engine, but we have had electric bikes (kept in an unheated garage) for some 15 years and they always have less "guts" on frosty winter days than in summer. Link to comment Share on other sites More sharing options...
peterboat Posted November 26, 2020 Report Share Posted November 26, 2020 On 23/11/2020 at 18:03, fudd said: Hello. Further to my charger thread, would I be better off with smaller batteries to build a 1000ah bank or fewer larger cells? I’m looking at Winston cells. Thank you. I have 36 KWHs at 72 volts of LifePo4s for my drive batteries, that is 30 batteries at 36 volts, it will give 10 hours cruising with no sun. These batteries have built in BMSs and all are connected to each other. A narrowboat will happily work at 48 volts and would require 1.5 KW to cruise at 3-4mph (figures from Finesse). I have a lot of solar 4.6 kw in fact, you will need over 2kW, 48 volt is a easy voltage to work with as 48 volt inverter/chargers are around. A 48 to 12 volt converter will take care of 12 volts needs 3 Link to comment Share on other sites More sharing options...
George and Dragon Posted December 5, 2020 Report Share Posted December 5, 2020 On 23/11/2020 at 18:10, IanD said: I assume you're aware of all the issues about assembling your own lithium bank and BMS? If not -- or even if you are -- I suggest you read this, it's long and a bit US/yacht biased but there's a *huge* amount of useful information in it: https://marinehowto.com/lifepo4-batteries-on-boats/ Well worth the read - thanks Ian Link to comment Share on other sites More sharing options...
Dr Bob Posted December 5, 2020 Report Share Posted December 5, 2020 On 23/11/2020 at 18:03, fudd said: Hello. Further to my charger thread, would I be better off with smaller batteries to build a 1000ah bank or fewer larger cells? I’m looking at Winston cells. Thank you. If you are asking this question then you have not done enough research!!!! See MP's comment below - and read these 2 sites. That was my first port of call before then pestering MP for all his knowledge! On 24/11/2020 at 20:14, MoominPapa said: Marinehowto and Nordkyn Design were my bibles when I was designing the installation on Melaleuca. I fear that too many people are jumping on this bandwagon with a "How hard can it be?" attitude and will likely get burned. Let's hope, not literally. MP. On 25/11/2020 at 11:43, fudd said: I will be seeking professional advice. If you do that then you will not be following the majority on here and installing 2nd hand batteries. The professionals will not sanction 2nd hand. The peeps on here know far more about our lithium systems than the professionals. Professionals will guide you on what and how to install a commercial system which will be fit for use by person getting it installed. The problem with 2nd hand systems is that they are not plug and play or idiot proof as the commercial systems are (at four times the cost!). The liability issue for a professional giving advice is a significant problem. It is very possible to instal a very safe system using LiFePO4s if you know what you are doing. Similarly it is very easy to instal a dangerous system if you dont know what you are doing. Spend time doing your research. Read ALL the Li threads here (posted in the last 2 years) and then come back and ask the question (along with the marinehowto and nordkyn sites). 2 Link to comment Share on other sites More sharing options...
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