Irish Rover
Well-Known Member
Same in Türkiye, last time I looked.
Truck batteries for boats
- Thread starter TSailors
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Refueler
Well-Known Member
Simply put :
Same AH size ... Li is about 3x the price but power delivery due to ability to discharge more gives about 1.5x power ... so net is about 2x cost and that is before I modify charging setups ...
PaulRainbow
Well-Known Member
One Eve cell is 3.2V, you need 4 to make a 12V "battery", todays cost for the cells £240. Sensible usable power would be 80% of the 280Ah, so 224Ah.
To get 224Ah of usable power from LA you need 448Ah. Thats's 4 x 110Ah @ about £100 each = £400
Almost half the price per usable Ah, 1/4 of the space and 1/4 the weight.
Dockhead
Well-Known Member
The last generation of LiFePo4 cells are cheaper than any lead batteries per Wh of usable power. You can get them from the official distributor in the UK, Fogstar Battery, which is a large and reputable supplier to industrial users. I see the price has dropped again -- now £59 (!) for Grade A 280K's. This is about half the cost of cheap leisure batteries per unit of usable power. No "Latvian pricing" involved. Hundreds of thousands of these are being sold every year for use in data centers and even electric utilities for "peak shaving".
Now you can't just buy the cells and stick them in your battery box. You need a BMS (the popular JK one costs about £140), and you will need to revise your whole system with appropriate charging sources, fuses, etc., so you can spend a couple thousand quid converting your boat, as I did this year. But that's a one-off expense. Now the cells last so long (8000 cycles) that you might say that the cells are a one-off expense, too.
I have upgraded my own boat for not much more than the cost of a new set of Trojan T105's, what I was previously using. That's including the capital expense of the electrical system conversion. But everything you spend upgrading your electrical system improves its function, so it's not money you are spending solely for the purpose of having lithium.
And if you don't want to convert your system, there are good drop-ins available, e.g. Litime, which also use EVE cells. batteries. These are cheaper than golf cart batteries per usable Wh, and similar in price to cheap leisure batteries, and will last probably 8x longer, so vastly cheaper over their life.
There is no longer any good reason to keep using lead batteries, in my view. They are not cheaper, they have a fraction of the usable cycle life, they are a faff to use, requiring you to fully charge them regularly, which can take hours of generator time because they charge so slowly for the last 15%. They are at least 5x heavier and much bulkier. There's simply nothing good about lead batteries.
PaulRainbow
Well-Known Member
Bit misleading/meaningless quoting Wh/Kg ? AH per £1 makes more sense to me.
£960 for the Lithium cells against £400 for the LA. If you are fitting the cells in 2 x 24V groups you will also need 2 x BMS and 2 x fuses/holders. You'll also need DC-DC chargers, most likely at least 2 and possibly a new mains charger. Cells and other equipment will likely come to about £2,000 total, against £400 for 4 x 110Ah LA.
Typical cost for the equipment to fit a single bank of 4 Lithium cells is £240 for the cells, but the BMS, fuse, fuse holder, DC-DC charger and mains charger adds another £600 (using Victron parts). Fitting a so called drop in battery doesn't change any of that, except the cells/BMS add up to more money and almost always feature inferior cells and/or BMS.
Lithium is definitely a better choice for some, but a waste of time for others and always costs much more then the cell prices that Lithium fans usually quote when making comparisons
PaulRainbow
Well-Known Member
This is incorrect. A typical drop in battery is just 4 x cells and a BMS in a box, you still need all of the other bits that you need by putting the cells together yourself.
Lithium makes no sense for thousand up thousand of small boats or boats used for day sailing/weekends. It is great for others.
Dockhead
Well-Known Member
Drop-ins are more expensive than using bare cells, but will not require much modification of charging systems in most boats.
LiTime 100AH drop-ins cost £240, which is not 3x the price of lead. The cheapest 110AH leisure battery is about £120, and that's not the right comparison. Leisure batteries are almost unusable for real off grid use -- I used to go through a set in less than a year. Golf cart batteries may last several years, but they cost £145 for 225AH x 6v. Usable power of lithium discharged to 20% is 1.6x of lead discharged to 50%, but don't forget that most off grid boat use doesn't allow getting the batteries to 100%; mostly they are charged only to 80% or 85%.
So net for drop-ins about the same cost as golf cart batteries, per usable power, and only 1.3x of the cheapest leisure batteries. Bare lithium cells are vastly cheaper.
And that's not considering cycle life. Leisure batteries claim 300 to 500 cycles to 50% DOD, but reality is much worse than that. Trojans claim 1100. EVE 280K's claim 8000 cycles, and unlike ratings for lead batteries, these seem to be realistic. But even if you take the ratings at face value, the lithium lives from 7.5x longer to more than 25x (!) longer than lead. So if you divide the cost per usable kWh by the number of cycles you expect to get out of it, it's evident that lithium is more than an order of magnitude cheaper.
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PaulRainbow
Well-Known Member
You keep saying this, but it isn't true.
You seem to have missed Refueler saying he's in Latvia, hence the prices he quoted.
Now you have all Lithium for your domestics, what's the engine battery arrangement ? One for each engine or do they share a battery. I assume you're 24V ?
Jim@sea
Well-Known Member
I used to sell batteries, but nothing like the size needed for my boat, I was advised to go to a Tractor dealer and have a look at the batteries they put in Tractors, and found that the batteries they sold were much bigger than the ones sold by Motor Factors.
PaulRainbow
Well-Known Member
Truck/tractor batteries are heavy duty commercial batteries. They have thicker plates to withstand the heavy current draw, which is why they are bigger and much heavier.
There is no benefit in fitting them to the average boat.
Dockhead
Well-Known Member
Wh/kg is to show the power density advantage. Weight is important on a sailboat, and to aging backs. Someone upthread mentioned it.Bit misleading/meaningless quoting Wh/Kg ? AH per £1 makes more sense to me.
£960 for the Lithium cells against £400 for the LA. If you are fitting the cells in 2 x 24V groups you will also need 2 x BMS and 2 x fuses/holders. You'll also need DC-DC chargers, most likely at least 2 and possibly a new mains charger. Cells and other equipment will likely come to about £2,000 total, against £400 for 4 x 110Ah LA.
Typical cost for the equipment to fit a single bank of 4 Lithium cells is £240 for the cells, but the BMS, fuse, fuse holder, DC-DC charger and mains charger adds another £600 (using Victron parts). Fitting a so called drop in battery doesn't change any of that, except the cells/BMS add up to more money and almost always feature inferior cells and/or BMS.
Lithium is definitely a better choice for some, but a waste of time for others and always costs much more then the cell prices that Lithium fans usually quote when making comparisons
Cost per Wh is just a different question.
Your comparison of £960 for lithium vs. £400 for lead is comparing only a single battery box of lead -- I had TWO. The £960 lithium is 13.4kWh of power, or maybe 11kWh if we are limiting discharge to 20%.
This power system replaces 8x Trojan T105's, not 4x, and which cost £1200 in the UK (about £2000 where I last bought them, in Denmark) and which provided only 5.4kWh of usable power.
The cells are arranged as two batteries of 280AH x 24v each, each controlled by a £140 JK BMS. My existing Victron Multiplus required no modification other than reprogramming. I added a Balmar alternator regulator and a Sterling alternator protector, for maybe £400 more. I added Type T fuses and Blue Seas contactors for each battery. I added monitoring gear -- one Victron BVM for each battery and a Victron Cerbo GX for the system as a whole. I changed all the cabling. I built a new battery box.
Total cost was approximately £2500 including the cells, with me and my friends doing all the labor, but much of that expense would have made sense even if I had stuck with lead. Particularly cabling, fuses, contactors, alternator regulator. I bought really good double-sheathed cabling with tin-plated copper 70mm2 conductor, and really top shelf cable lugs. Vast improvement on the original.
So for only about £500 more than what I last paid for lead batteries, I have totally upgraded my power system to double the capacity, vastly improve its functioning, renew all the cabling, add fuses and monitoring. I consider this a very great bargain.
PaulRainbow
Well-Known Member
If you could get Lithium cells at UK prices they would definitely be a good move for you next time you need new batteries.
Irish Rover
Well-Known Member
Thanks Paul. I'm actually sorry I didn't bite the bullet last time.
PaulRainbow
Well-Known Member
But you quoted 2.2Kwh of usable power. Your comparisons are inconsistent. You compared the power difference to 4 x LA batteries, but now you want to compare the price difference to 8 x batteries.
I agree it was the best way forward for you, it was for me when i changed last year. I fitted new batteries, Multiplus, 900W of solar etc and it all works great, virtually no electric bills, no need to run the generator etc.
That said, i still believe that Lithium isn't for everyone, simple LA works for many, many boats.
I'm still curious about your engine starting arrangements ?
PaulRainbow
Well-Known Member
They'll be even cheaper next time, i suspect.
Dockhead
Well-Known Member
I would be surprised if cost in Latvia is any different from anywhere else in Europe. He will get EVE cells from NKON in Holland just like I did, and a bit cheaper still since his VAT rate is lower. I was actually living in Latvia myself at the time I bought my last set of lead batteries; I ordered them from Germany as that was cheaper than buying locally.
As to engine and generator starting, my boat was originally designed with completely separate 12v start batteries (both truck batteries) with their own separate charging systems for both main and genset. My main engine has two alternators, the standard 12v Yanmar one, which charges the start batt and nothing else, and a 100A x 24v Leece Neville school bus alternator. There is no connection of any kind between these 12v starting systems, and the 24v house power system. I didn't touch these systems at all.
Dockhead
Well-Known Member
The first comparison was with what was located in the single battery box space which the new power system occupies.
The second comparison was with the two lead banks which the new power system replaced. Sorry if that was confusing. The first comparison is just to show the remarkable increase in power density.
Simple LA makes sense, in my opinion, only for people who just don't spend much time at anchor not plugged into shore power, and therefore cycle their batteries so little that lead batteries actually last a long time. The moment you start using your batteries much, the advantages of lithium become completely overwhelming.
For me, lithium solved an extremely frustrating and expensive problem of having to replace batteries every three years at most. I use my batteries pretty hard, at least 3 months and some years 6 months on board per year, most of that not plugged in. For years I was on a mid-river mooring on the Hamble with no shore power.
If you mostly sail from marina to marina, and only spend some weekends and the odd two week vacation on board, then the problems of lead batteries are less obvious.
So of course use case is highly relevant.
Actually on that subject -- my boat wasn't originally designed to run off batteries for extended periods at all. She has a continuous rated heavy duty generator, a 6.5kW Kohler, and was designed to be operated like a motor yacht -- genset runs continuously if you're not plugged in. My boat had two separate 24v banks, only one of which was connected to house loads (the other was for thruster, windlass, winches). So I only had about 2.2kWh of usable power for house loads. When I bought the boat 15 years ago, I connected the two banks together so both could be used for house loads. I don't like to run the generator continuously; pace to all power boaters.
Refueler
Well-Known Member
Home goal there mate !
Yes I can buy in from outside Latvia ... but since Covid - shipping costs into Latvia have skyrocketed when getting from other EU states.
But I have no wish to 'construct' my own battery banks - not of the size you are suggesting anyway .... I have spot welding gear to create small hobby battery packs ... and that's as far as I will go ..
I would appreciate lighter - greater capacity battery bank occupying same as the twin 90 AH domestic I have now .......... but I can buy 90 AH Lead Acid for about 85 euros each .. straight drop in with no modifications.
I would prefer to spend a bit on upgrading the Solar setup .. as the panel fitted to deck appears to be 'worn out' ... it does work - but being an old panel - not as well as a later new panel would.
PaulRainbow
Well-Known Member
"constructing" a Lithium pack doesn't involve any welding. You simply clamp them together with some ply or perspex etc, under mild compression, or clamp them and strap them together with glass reinforced tape. I connect my cells together then with flexible busbars.
I would much rather assemble my own cell packs, i know what cells i'm using and i use my choice of BMS (JK). As they are not in clunky plastic (or Heaven forbid metal), boxes they are more compact and can be neatly fitted to the boat.
PaulRainbow
Well-Known Member
I take it you can start the main engine with the generator battery, in case of emergency ?