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Post by sabre on Nov 17, 2023 13:59:11 GMT 12
Many of the large European yacht manufacturers are now fitting Lifepo4 from new.
Meanwhile in NZ there are still lots of club welding knuckle draggers who think the very volatile, unforgiving and short lifespan LA's are the ducks nuts..
Just crazy.
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Post by dutyfree on Nov 17, 2023 15:57:41 GMT 12
Can lead carbon be used in a mixed use setup ie where I have two batteries that are start and house combined?
Yes I could split them, but more $$$
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Post by BatteryGuy on Nov 17, 2023 19:09:38 GMT 12
I am quite bemused with all the hand wringing over the safety of Lifepo4 batteries and I am still convinced many of you are confusing lithium-ion batteries with lithium-ion phosphate. LiFePO4 is actually a Lithium-ion battery. It is one of the many chemistries available of the Lithium-ion battery chemistry. You are right that it is very very safe. However it's not actually the safest Lithium-ion technology that award goes to Lithium Titanate Oxide (LTO). Unfortunately LTO does not map very well to our boat voltages. LiFePO4 maps very well to the 12v voltage range, while LTO hits over 16v when fully charging and therefore is more complicated to get working with the typical 12v electronics found on boats. Sparky, the poal tug uses LTO chemistry. Primarily because of its safety, but also because it can provide more Watts on demand than LFP. LTO can be discharged at over 35C while LFP typically 1C maximum (although cylindrical cells can reach 10C - but boats usually use prismatic cells).
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Post by ComfortZone on Nov 17, 2023 19:29:43 GMT 12
There is no reason not to fit alternator output directly to a Li battery bank as long as you set it up properly. Very good feature in BNZ a few years ago on this that wasn't just advertorial boatingnz.co.nz/better-batteries/Key parts to this guy's installation that were a little different to standard practice were: 1. Having separate load and charge busses 2. Using a "make before break" relay to divert the charge from the Li battery to a Lead Acid, to avoid frying the alternator diodes If I was considering a Li installation I would follow his installation in principle, with the addition of an extra "essential services" battery for navigation instrumentation/comms/nav lights etc so if the Li battery was cut off by the BMS you still have a power supply to keep you going PS, what would be the advantage of a 'make before break' over a DC-DC charger? I assume it would mean you could run much high charging current without the current limitation of DC chargers. In the article they were running a 165amp alt, which is just silly big. They rightly identified that most of the time it was doing less than 25 amps. My alt is 75amp and the new lead carbons are 300 ah, meaning in theory they can take 90 amps. I'm only ever seen them take 25-30 amps max (not counting the start batt). But then I only use about 25 amp/hrs a day, so we never get into massive charging currents. The "make before break" is solely to protect the alternator, specifically its diodes. If the Alternator is pumping out amps and the battery is suddenly cut off it goes WTF and potentially blows its diodes. A lithium battery will take all the amps the alternator can throw at it until it is full, then the BMS cuts off the charge. This is one of their key advantages, you can significantly reduce engine run time c.f Lead Acid batteries for charging, if the likes of solar is not sufficient.. The article is not so well written, the reference to less than 25 amps was for their LA batteries, not Lithiums. All comes back to LA batteries charge acceptance rate. I ran into this on our winter cruise, I have 480ahr of SLA's and a 140Amp alternator with a 3 step reg. The weather in Vanuatu was quite overcast and hence was not getting much out of solar (worsened by a subsequently discovered faulty circuit breaker), so had to use the engine alot for charging. I was operating in the band of typ 330 - 380ahr, because I just could not get the batteries back up to full charge on an hour's engine run, which also cooled the freezer (it has both engine drive and 12V DC compressors). The alternator would initally go to full output of 140A, within 15min below 100 and another 30min later below 50A. It was only when I was on the marina in Noumea with shore power that the Inverter/charger was able to bring the batteries back up to 100%
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Post by ComfortZone on Nov 17, 2023 19:33:04 GMT 12
Yes an extra LA is what I was thinking too for navs and comms . Good article and we felt the same with our household bank of top notch German LAs that lasted only 4 years that took most of the day to charge . The LifePo4s are done by midday or 2.5 hours on generator charge . Funny. I know that boat, hadn't seen the article. Shortly after fitting that system there electrical system failed completely and they couldn't do anything. If I recall they had to hard wired the winches to the lithium batteries so they could get back to opua. I think the phrase 'probably overcomplicated the solution" was banded around... They were really happy they had the lithium cause it meant they had ample power to run the boat, even tho they couldn't access it without bypassing all the magic and couldn't charge it... with the exception of the split busses, the installation on that boat is exactly what is required by AS 3004.2. I have a copy of the wiring schematic from Enertec for a Beneteau 473's installation and yes it is complicated because of the additional protection devices required. This is the "cost" to take advantage of the benefits of Lithium batteries.
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Post by fish on Nov 17, 2023 19:42:45 GMT 12
Can lead carbon be used in a mixed use setup ie where I have two batteries that are start and house combined? Yes I could split them, but more $$$ I got the Kijo ones. They have very high 1 sec current discharge ratings, so I was keen on putting one in for my start batt (which needed replacing at the same time). So I thought they looked good for a start batt. I asked the supplier and he said no, so I asked him to ask the manufacturer and they said no. I don't actually understand why. They appear to have very good current discharge characteristics, but they aren't tested against the cold cranking amps CCA and marine cranking amps MCA standards. One of the guys on the other site uses the same Kijo lead carbons for bow thruster and anchor winch batt. Note that the Kijo ones are a bit different to some of the lead carbons designed / targeted at solar off grid installations. The other ones don't appear as well suited to marine house battery installations. Mainly through size and weight (they are massive, designed for putting in a shed with 1,500 A/hr banks kind of thing.
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Post by dutyfree on Nov 17, 2023 19:49:25 GMT 12
Thanks for that. I had been planning to split the starboard dual battery setup, so maybe will after all. May stick a carbon in when I do that.
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Post by em on Nov 17, 2023 19:51:24 GMT 12
I am quite bemused with all the hand wringing over the safety of Lifepo4 batteries and I am still convinced many of you are confusing lithium-ion batteries with lithium-ion phosphate. LiFePO4 is actually a Lithium-ion battery. It is one of the many chemistries available of the Lithium-ion battery chemistry. You are right that it is very very safe. However it's not actually the safest Lithium-ion technology that award goes to Lithium Titanate Oxide (LTO). Unfortunately LTO does not map very well to our boat voltages. LiFePO4 maps very well to the 12v voltage range, while LTO hits over 16v when fully charging and therefore is more complicated to get working with the typical 12v electronics found on boats. Sparky, the poal tug uses LTO chemistry. Primarily because of its safety, but also because it can provide more Watts on demand than LFP. LTO can be discharged at over 35C while LFP typically 1C maximum (although cylindrical cells can reach 10C - but boats usually use prismatic cells). Thanks for that , learn something everyday . Never knew of LTO chemistry until now .
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Post by sabre on Nov 17, 2023 19:58:19 GMT 12
I am quite bemused with all the hand wringing over the safety of Lifepo4 batteries and I am still convinced many of you are confusing lithium-ion batteries with lithium-ion phosphate. LiFePO4 is actually a Lithium-ion battery. It is one of the many chemistries available of the Lithium-ion battery chemistry. You are right that it is very very safe. However it's not actually the safest Lithium-ion technology that award goes to Lithium Titanate Oxide (LTO). Unfortunately LTO does not map very well to our boat voltages. LiFePO4 maps very well to the 12v voltage range, while LTO hits over 16v when fully charging and therefore is more complicated to get working with the typical 12v electronics found on boats. Sparky, the poal tug uses LTO chemistry. Primarily because of its safety, but also because it can provide more Watts on demand than LFP. LTO can be discharged at over 35C while LFP typically 1C maximum (although cylindrical cells can reach 10C - but boats usually use prismatic cells). Great info thanks. Seems there is a lot of battery developement happening which is understandable. It will be interesting to see where it goes. I believe that Lifepo4 is actually Lithium-(iron) phosphate which is much more stable than Lithium-ion that is prone to thermal runaway, exploding, catching fire etc.
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Post by fish on Nov 17, 2023 20:11:39 GMT 12
I don't care how good anyone says a battery is, I would never, ever discharge a battery at 35C on a boat.
Maybe in a large paddock, but never on a boat.
If I've got my numbers right, a 100Ah battery could put out 3,500 amps. That is just silly. Wires, lug bolts etc would spontaneously combust at numbers like that. And I don't want to ask what sort of device needs that. Sounds more like a capacitor than a battery.
PS, the Kijo Lead-carbon's I've got (100Ah) say the max discharge is 1,200A for 5 secs. Hence why I thought they'd be a good starting battery. One of lead-carbon's attributes is capacitor like behaviour in some situations.
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Post by BatteryGuy on Nov 18, 2023 7:23:07 GMT 12
I believe that Lifepo4 is actually Lithium-(iron) phosphate which is much more stable than Lithium-ion that is prone to thermal runaway, exploding, catching fire etc. You're confusing the atomic particle with the element. An Ion is a positively or negatively charged particle, more specifically a Cation or Anion respectively. Iron is an element with the periodic table with the symbol Fe hence the Fe in LiFePO4 In all batteries, of all types, Ion's move from the Anode to the Cathode when charging and from the Cathode to the Anode when discharging. In a LFP battery, LiFePO4 (Lithium Iron Phosphate) is the Cathode, and the Anode is a metallic graphite material. Then there's an electrolyte, which in LFP is also Lithium salt, that provides a conductive path between the terminals. When charging, or discharging, Lithium-ions move through the electrolyte from the cathode to the anode and vice versa. The energy a LFP battery provides comes from shifting lithium ions between a cathode and anode material. All Lithium batteries are Lithium-ion but the Cathodes are different chemistries, this different cathode material gives them advantages and disadvantages. Eg LiCoO2 batteries found in many mobile phones and laptops, are lighter compared to lfp, pack bucket loads of power compared to lfp, but are way more susceptible to thermal runaway. But they are still Lithium-ion.
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Post by BatteryGuy on Nov 18, 2023 8:14:17 GMT 12
I don't care how good anyone says a battery is, I would never, ever discharge a battery at 35C on a boat. Maybe in a large paddock, but never on a boat. If I've got my numbers right, a 100Ah battery could put out 3,500 amps. That is just silly. Wires, lug bolts etc would spontaneously combust at numbers like that. And I don't want to ask what sort of device needs that. Sounds more like a capacitor than a battery. PS, the Kijo Lead-carbon's I've got (100Ah) say the max discharge is 1,200A for 5 secs. Hence why I thought they'd be a good starting battery. One of lead-carbon's attributes is capacitor like behaviour in some situations. It's a matter of use case. In a starter battery, multiple C is common. A 10ah lto battery can be used to start the engine easily. Both Mercedes and BMW have started including lightweight LTO batteries with there cars. They can dump 2000amps inrush current without blinking to start a v8 multiple times. For starting the engine, winches or bow thrusters on boats they are the perfect use case. For energy storage at slow release not so much so. Ignoring some special cells like headway cylindrical that aren't typically found in the packs we can buy for our boats... LFP tops out at 1C. Realistically all the literature says 0.5C for prolonging the life of the cell. Now if you wanted to run a 2kw inverter on your boat for 5minutes, eg to boil the kettle, then you need 200amps. So you really need 400ah of lfp. Lfp simply isn't a good use case for that. On the flip side you could have 50ah of lto, that you could run at 200amps without any concern what so ever. So it totally depends on the use case. Additionally lfp generally has a max charge rate of 0.5C. So if you have a 200a alternator you need 2hrs to charge a 100ah lfp. Now if you had 100ah lto, you could charge that battery in 30minutes.
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Post by DuckMaster on Nov 18, 2023 9:11:49 GMT 12
You're putting your faith in a made specifically to drag in money affiliate website written by who the fuck knows against the entire airline safety machine, shipping safety machine and lets not mention all the rest of real life evidence out there? That's a big call dude.
Yeah nah plenty of evidence everywhere you look that lifepo4 is very safe and the only "evidence" of risk is antedotal including some youtube video of a guy apparently whacking a battery with an axe. Why do airlines prohibit the shipping of Lifepo4 batteries if they are so safe? Can only be shipped inside equipment. Only if 30% soc and only if under a specific watt/hr (which equates to less than 1kg). Will not accept transport of any sized battery on its own. Not even a single 30g cell! Are the airlines somehow in cahoots with the lead acid cartel? Try and buy a Lithionics battery, supposedly the bee knees in lfp battery tech and get it shipped via a plane... Not a single airline will carry it... The battery isn't even being used when being shipped! But somehow you believe they are safe on a boat when we are charging them with solar, hydro, wind or alternator. And discharging them with our inverters... Tells me they (and the trolls) know something you don't...
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Post by sabre on Nov 18, 2023 9:55:29 GMT 12
I believe that Lifepo4 is actually Lithium-(iron) phosphate which is much more stable than Lithium-ion that is prone to thermal runaway, exploding, catching fire etc. You're confusing the atomic particle with the element. An Ion is a positively or negatively charged particle, more specifically a Cation or Anion respectively. Iron is an element with the periodic table with the symbol Fe hence the Fe in LiFePO4 In all batteries, of all types, Ion's move from the Anode to the Cathode when charging and from the Cathode to the Anode when discharging. In a LFP battery, LiFePO4 (Lithium Iron Phosphate) is the Cathode, and the Anode is a metallic graphite material. Then there's an electrolyte, which in LFP is also Lithium salt, that provides a conductive path between the terminals. When charging, or discharging, Lithium-ions move through the electrolyte from the cathode to the anode and vice versa. The energy a LFP battery provides comes from shifting lithium ions between a cathode and anode material. All Lithium batteries are Lithium-ion but the Cathodes are different chemistries, this different cathode material gives them advantages and disadvantages. Eg LiCoO2 batteries found in many mobile phones and laptops, are lighter compared to lfp, pack bucket loads of power compared to lfp, but are way more susceptible to thermal runaway. But they are still Lithium-ion. I'm not confusing anything. You referred to them as lithium-ion phosphate when they are in fact lithium-iron phosphate. Not a biggy though 👍
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Post by sabre on Nov 18, 2023 10:06:23 GMT 12
Yeah nah plenty of evidence everywhere you look that lifepo4 is very safe and the only "evidence" of risk is antedotal including some youtube video of a guy apparently whacking a battery with an axe. Why do airlines prohibit the shipping of Lifepo4 batteries if they are so safe? Can only be shipped inside equipment. Only if 30% soc and only if under a specific watt/hr (which equates to less than 1kg). Will not accept transport of any sized battery on its own. Not even a single 30g cell! Are the airlines somehow in cahoots with the lead acid cartel? Try and buy a Lithionics battery, supposedly the bee knees in lfp battery tech and get it shipped via a plane... Not a single airline will carry it... The battery isn't even being used when being shipped! But somehow you believe they are safe on a boat when we are charging them with solar, hydro, wind or alternator. And discharging them with our inverters... Tells me they (and the trolls) know something you don't... Dam your arguments just get more and more tedious to the point of being disturbing. Have a google of what type of battery Boeing use to run their aircraft.
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