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Post by em on Nov 16, 2023 6:48:39 GMT 12
Yeah alternator charging two different chemistries is the problem ….fish wrote a book on it here and on creworg .
There’s enough enough space on the boat to have two solar controllers . when it comes to it I could keep the main solar array for LifePo4 house bank with a suitable charger inverter . There’s already a decent victron charge controller that came with the boat so we would probably put a single panel on deck for start start battery and keep the alternator connected to start batt only . There’s also an option of two alternators the engine has mounts for a fridge compressor that will take an alternator but my brain hurts thinking about it , everything is fine at the moment !
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Post by DuckMaster on Nov 16, 2023 7:39:57 GMT 12
From my research I have found that Lifepo4 batteries are incredibly safe and stable when used in a solar powered system. Their charging parameters are very easy to set up using a programmable solar charger. Charging with an alternator and wind turbines adds a lot of complexity. I think most lithium batteries going into boats will be Lifepo4. My money would be that the boat fire above was more likely started by a drill battery or similar. But yeah probably give the temu electronics a wide berth.. While it would seem that way the reality is that although the batteries do not seem to catch on fire the issue is that they get so hot that the surroundings catch on fire. I saw a YouTube of a guy who had a Lifepo4 you mention burst and vent gas everywhere for ages, long enough for the fire brigade to get there and it was still gassing when he got home 30mins later. The whole garage was full of toxic smoke. Firebrigade said it was 275deg (guess that is f as it was usa) but that's still 135c... He had the battery against a concrete wall and in a metal box on a concrete floor. Boats aren't going to be that.... They will be wood or glass over foam etc... And while it seems like lifepo4 doesn't catch on fire the material around it and next to it can... And 135c is going to start a fire Just seems like the wrong tech for a boat to me... The video was a story about it, not the actual event. Will try and find it again if you are interested?
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Post by sabre on Nov 16, 2023 8:42:12 GMT 12
From my research I have found that Lifepo4 batteries are incredibly safe and stable when used in a solar powered system. Their charging parameters are very easy to set up using a programmable solar charger. Charging with an alternator and wind turbines adds a lot of complexity. I think most lithium batteries going into boats will be Lifepo4. My money would be that the boat fire above was more likely started by a drill battery or similar. But yeah probably give the temu electronics a wide berth.. While it would seem that way the reality is that although the batteries do not seem to catch on fire the issue is that they get so hot that the surroundings catch on fire. I saw a YouTube of a guy who had a Lifepo4 you mention burst and vent gas everywhere for ages, long enough for the fire brigade to get there and it was still gassing when he got home 30mins later. The whole garage was full of toxic smoke. Firebrigade said it was 275deg (guess that is f as it was usa) but that's still 135c... He had the battery against a concrete wall and in a metal box on a concrete floor. Boats aren't going to be that.... They will be wood or glass over foam etc... And while it seems like lifepo4 doesn't catch on fire the material around it and next to it can... And 135c is going to start a fire Just seems like the wrong tech for a boat to me... The video was a story about it, not the actual event. Will try and find it again if you are interested? Any battery will start a fire if it gets hot enough. However, Lifepo4's run at a very low and stable temperature so highly unlikely to have issues and they are considered far safer than agm which many boats have. There is clearly some old wives tales that have taken root that are disconected from reality and causing people to miss out on some incredible technology. www.solar4rvs.com.au/buying/lithium-vs-lead-acid-batteries-a-comprehensive-comparison/Several chemistries of Lithium such as Lithium-Ion, Lithium Iron Phosphate and Lithium Polymer are available. The LiFePO4 batteries are the safest type of Lithium batteries as there is no danger of the battery erupting into flames as with Lithium-Ion. They will not overheat, and they will not catch on fire, even if punctured.
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Post by sabre on Nov 16, 2023 8:55:35 GMT 12
Yeah alternator charging two different chemistries is the problem ….fish wrote a book on it here and on creworg . There’s enough enough space on the boat to have two solar controllers . when it comes to it I could keep the main solar array for LifePo4 house bank with a suitable charger inverter . There’s already a decent victron charge controller that came with the boat so we would probably put a single panel on deck for start start battery and keep the alternator connected to start batt only . There’s also an option of two alternators the engine has mounts for a fridge compressor that will take an alternator but my brain hurts thinking about it , everything is fine at the moment ! If its working and you have enough power then yeah why mess with it. My boat has no engine charging so the solar/battery is a stand alone system. Very, very simple just like its owner..
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Post by fish on Nov 16, 2023 8:56:24 GMT 12
18 months in on our LifePo4s and they are fine hooked up to 3000w of solar . The cables from the charger don’t even get warm with panels at full output and batteries don’t get much warmer than ambient temp . Would happily have them on the boat if charging them wasn’t such a dark art I have foumd the same on the caravan which has 660w/24v. I dont have a temp gauge but the battery is always cool to the touch. I think there is a lot of confusion around the different lithium tech. Lifepo4 are actually considered to be safer and less prone to catching fire than AGM. Is it just the alternator charging on the boat that is the issue? I haven't really looked into it but it sounds like the alternator gets fried when the bms instantly shuts down charging? I think it is the same issue with wind turbines? I set up the solar charging parameters for mine on the Epever MT50 and everything is working really well. Theoretically if the MT50 or the solar controller glitched then the BMS would shut things down to prevent cooking the battery. I really recommend you get a temp gauge. Even the FLA / AGM's need temp compensation for the optimum charging voltage. Can't do that without a temp gauge. The warmer the ambient temp the lower the charge voltage is needed. (think I have that around the right way). That and the basic concept of a thermal run-away. As a batt heats up it can take more energy so heats up more, so can take more energy, after a while that energy has no-where to go. Temp probes are a direct plug in for Epevers. Wont be expensive on Aliexpress and will be legit gear. And yes, the Lithium BMS's are deadly for alternators. The whole point of the BMS is to cut off the battery if it gets too much charge. Odds on the alt is going hard out if the batt is getting too much charge. You get an uncontrolled load dump on the alternator which fries it. The alternator is putting out maximum current, and in a milli-second there is no-where for that current to go... boom! About the only way to deal with it is to charge via another battery (like the start) via a DC-DC charger. If the BMS shuts down, the current goes into the start (AGM) and the normal control systems can do a controlled shutdown of the alternator. The issue I couldn't get my head around was acceptable charging current for the start batt. One of the big advantages of Lithium is their high charge current acceptance / fast charging. Up to 100% of the amp/hours (C100). I'm not aware of a traditional batt / start batt that can handle more than 10% of it's capacity. Lead-carbon can handle loads, but it is till max 30%. Fairly sure AGM type start batts can pass through greater current than they accept, but what I couldn't work out was what happens when the lithium is full and not taking charge? How do you get an alternator smart charger to not give the start batt excessive current? That, and DC-DC chargers with high current start getting very expensive. 10amp to 30amp DC chargers aren't too bad, but much more than that and the price goes up a lot. It appears there is a technical limitation on the current a DC charger can do, so you end up needing two or more, which obviously doubles the cost. That is all just to achieve the fast charge capability of Lithium. That shifts the economics of installing Lithium to a point where it is far better and cheaper to just stick with conventional tech and plan to replace it every 5 years or so. Solar systems don't have the uncontrolled load dump issue from the BMS that alternators or wind gennies do. So if you have a straight solar charging system lithiums are an easier install. BUT if you are solar charging you don't need the high charge acceptance capability of Lithium. You aren't going to be charging them in short times under engine (like leaving an anchorage). That means you are paying a lot of money for other lithium attributes, being lots of cycles and ability to tolerate partial states of charge. Weight may be a consideration but not often. There are lower cost and more established technologies around that tick those boxes. Hence why I ended up with Lead-carbon. It is basically AGM tech and has been around for ages. Can tolerate partial state of charge without sulphating, has high cycle life (cause the negative plate can't shed like in a FLA), have high charge acceptance, and if you need, have very high discharge current (so you can run an inverter and power up a microwave or coffee machine for short periods, like making a coffee or heating up a pie) Not sure why else you would need massive current draw. Lead-carbons are heavy. In my view that is about their only downside. But the plus side is cost. I got 300 AmpHrs for $900. And a straight like for like install with the old FLA house batts (no new hardware). Not planning on taking them below 50% so 150 AH usable capacity. To get lithium of that capacity range (assuming 80%DOD, not 100%) you are talking about $2,000 for a cheap brand (SOK I think), but not super dodgy cheap. As soon as you add on anything to enable the install, like a DC-DC charger ($500 plus), the economics go out the window. You also have the whole issue of cost V quality. You can get cheaper lithium batts, but will then achieve 5,000 cycles or just 500 like the old AGMs? You could get Enertec Lithium's and know they will perform, but will set you back $5k plus the install costs / items. For offgrid solar I'd probably go Lead-carbon over Lithium. For a yacht install with solar and alternator charging I did go Lead-carbon over lithium. Really, in my view, Lithium are only good for electric vehicles, where you need very fast charging current, massive current draw, light weight and high cycles. They may have a place in certain niche applications on boats, but the majority of the time there are better options out there, especially for standard cruising yachts.
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Post by DuckMaster on Nov 16, 2023 8:58:45 GMT 12
While it would seem that way the reality is that although the batteries do not seem to catch on fire the issue is that they get so hot that the surroundings catch on fire. I saw a YouTube of a guy who had a Lifepo4 you mention burst and vent gas everywhere for ages, long enough for the fire brigade to get there and it was still gassing when he got home 30mins later. The whole garage was full of toxic smoke. Firebrigade said it was 275deg (guess that is f as it was usa) but that's still 135c... He had the battery against a concrete wall and in a metal box on a concrete floor. Boats aren't going to be that.... They will be wood or glass over foam etc... And while it seems like lifepo4 doesn't catch on fire the material around it and next to it can... And 135c is going to start a fire Just seems like the wrong tech for a boat to me... The video was a story about it, not the actual event. Will try and find it again if you are interested? Any battery will start a fire if it gets hot enough. However, Lifepo4's run at a very low and stable temperature so highly unlikely to have issues and they are considered far safer than agm which many boats have. There is clearly some old wives tales that have taken root that are disconected from reality and causing people to miss out on some incredible technology. www.solar4rvs.com.au/buying/lithium-vs-lead-acid-batteries-a-comprehensive-comparison/Several chemistries of Lithium such as Lithium-Ion, Lithium Iron Phosphate and Lithium Polymer are available. The LiFePO4 batteries are the safest type of Lithium batteries as there is no danger of the battery erupting into flames as with Lithium-Ion. They will not overheat, and they will not catch on fire, even if punctured. The guy is literally holding an exploded lifepo4 battery from his solar installation in the video and explaining that the temperature when it was gassing was 275deg... And you call it an old wives tale? Yes the battery didn't burst into flames he is very clear on that. The fire brigade waited for the thing to stop gassing and for the temperature to drop there were no flames. But if that had been on a boat @ 275deg and the boat material would of caught on fire just from the heat. In the video they talk about what could of caused it, was it a faulty charger? Was it a bad cell that had a manufacturing fault? Was it a faulty bms? Bms has temp monitors volt monitor disconnect etc - all the bells and whistles... The scary thing is they have no way of knowing. Bottom line is that these batteries can and do gas and burst. While they don't spontaneously burst into flames, the heat caused from the gassing is enough to start a fire on a boat due to the confined installation nature on a boat.
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Post by DuckMaster on Nov 16, 2023 9:10:37 GMT 12
They will not overheat, and they will not catch on fire, even if punctured. This video of intentionally punctured lifepo4 spewing flame like a flame thrower contradicts your position... youtu.be/07BS6QY3wI8?si=bnM-rdHXsa8vRaG4Fact is, they can overheat, they can burst into flames when punctured.
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Post by harrytom on Nov 16, 2023 9:10:58 GMT 12
Lifepof lithium melt apparently rather catch fire or explode.So maybe safer than standard lithium?
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Post by fish on Nov 16, 2023 9:25:53 GMT 12
Any battery will start a fire if it gets hot enough. However, Lifepo4's run at a very low and stable temperature so highly unlikely to have issues and they are considered far safer than agm which many boats have. There is clearly some old wives tales that have taken root that are disconected from reality and causing people to miss out on some incredible technology. www.solar4rvs.com.au/buying/lithium-vs-lead-acid-batteries-a-comprehensive-comparison/Several chemistries of Lithium such as Lithium-Ion, Lithium Iron Phosphate and Lithium Polymer are available. The LiFePO4 batteries are the safest type of Lithium batteries as there is no danger of the battery erupting into flames as with Lithium-Ion. They will not overheat, and they will not catch on fire, even if punctured. The guy is literally holding an exploded lifepo4 battery from his solar installation in the video and explaining that the temperature when it was gassing was 275deg... And you call it an old wives tale? Yes the battery didn't burst into flames he is very clear on that. The fire brigade waited for the thing to stop gassing and for the temperature to drop there were no flames. But if that had been on a boat @ 275deg and the boat material would of caught on fire just from the heat. In the video they talk about what could of caused it, was it a faulty charger? Was it a bad cell that had a manufacturing fault? Was it a faulty bms? Bms has temp monitors volt monitor disconnect etc - all the bells and whistles... The scary thing is they have no way of knowing. Bottom line is that these batteries can and do gas and burst. While they don't spontaneously burst into flames, the heat caused from the gassing is enough to start a fire on a boat due to the confined installation nature on a boat. I'm not sure if using one example from youtube is the most compelling arguement. I think it is far more important to understand the technical limitations and what is required to install and set them up properly. Example of an AGM battery fire on a yacht in Gibraltar that was reported in one of the UK sailing magazines (probably Practical Boat Owner I think). Guy got back to his boat post lock-down and obviously needed to charge the batteries. He left the shore powered charger on for FIVE DAYS, cause the battery monitor was out of calibration and telling him they weren't yet at 100%. For some reason, charging the AGM's for five days made them start smoking and emitting fumes and flames. The lesson there is to not blindly rely on one device, or to apply some common sense. As Sabre says, any battery can catch fire. In my view, things happen faster with Lithiums, so it is quicker to fuck something up. For me, the best example is the very little warning a lithium is reaching full charge. It can be charging at full current then, nekminnit, its full and cooking itself. That is a specific technical aspect that needs to be understood by the user. I do worry with even good batts like Enertec, that people are told the BMS is all singing, all dancing, but don't understand wider technical limitations, like uncontrolled load dump impacts on an alternator. Or lack of internal resistance in a battery allowing very high charge current, which can fry cables and switches and what-not. It is not always the battery that starts the fire, but ancillary bits and pieces.
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Post by sabre on Nov 16, 2023 9:28:04 GMT 12
I have foumd the same on the caravan which has 660w/24v. I dont have a temp gauge but the battery is always cool to the touch. I think there is a lot of confusion around the different lithium tech. Lifepo4 are actually considered to be safer and less prone to catching fire than AGM. Is it just the alternator charging on the boat that is the issue? I haven't really looked into it but it sounds like the alternator gets fried when the bms instantly shuts down charging? I think it is the same issue with wind turbines? I set up the solar charging parameters for mine on the Epever MT50 and everything is working really well. Theoretically if the MT50 or the solar controller glitched then the BMS would shut things down to prevent cooking the battery. I really recommend you get a temp gauge. Even the FLA / AGM's need temp compensation for the optimum charging voltage. Can't do that without a temp gauge. The warmer the ambient temp the lower the charge voltage is needed. That and the basic concept of a thermal run-away. As a batt heats up it can take more energy so heats up more, so can take more energy, after a while that energy has no-where to go. Temp probes are a direct plug in for Epevers. Wont be expensive on Aliexpress and will be legit gear. And yes, the Lithium BMS's are deadly for alternators. The whole point of the BMS is to cut off the battery if it gets too much charge. Odds on the alt is going hard out if the batt is getting too much charge. You get an uncontrolled load dump on the alternator which fries it. The alternator is putting out maximum current, and in a milli-second there is no-where for that current to go... boom! About the only way to deal with it is to charge via another battery (like the start) via a DC-DC charger. If the BMS shuts down, the current goes into the start (AGM) and the normal control systems can do a controlled shutdown of the alternator. The issue I couldn't get my head around was acceptable charging current for the start batt. One of the big advantages of Lithium is their high charge current acceptance / fast charging. Up to 100% of the amp/hours (C100). I'm not aware of a traditional batt / start batt that can handle more than 10% of it's capacity. Lead-carbon can handle loads, but it is till max 30%. Fairly sure AGM type start batts can pass through greater current than they accept, but what I couldn't work out was what happens when the lithium is full and not taking charge? How do you get an alternator smart charger to not give the start excessive current? That, and DC-DC chargers with high current start getting very expensive. 10amp to 30amp DC chargers aren't too bad, but much more than that and the price goes up a lot. It appears there is a technical limitation on the current a DC charger can do, so you end up needing two or more, which obviously doubles the cost. That is all just to achieve the fast charge capability of Lithium. That shifts the economics of installing Lithium to a point where it is far better and cheaper to just stick with conventional tech and plan to replace it every 5 years or so. While it wouldn't hurt to have a temp sensor, from what I have read, thermal runaway is almost impossible with lifepo4 even when they have artifially tried to trigger them. You would have to seriously abuse them to have any issues especially in a modest system like mine. You have obviously had a good suss of the other issues involved so clearly know a lot more than me. Personally if I was adding lifepo4 to an existing system with an alternator/wind turbine, I would make it stand alone with just solar as the charge source. I think most people once they go lifepo4 will be kicking themselves they didn't do it earlier. When I first got mine I hooked it up to our 7kg washing machine and put a full load through. At the end of the cycle I literally heard the battery yawn and go back to sleep. From memory resting voltage was 0.2 less than when it started. I then thought right lets hook you up to the deep freeze in the garage. Everytime I walked past over the next couple of days I could hear the battery snigger and mutter something about what a cushy life it had. The tech is seriously good and is 100years ahead of fla etc
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Post by sabre on Nov 16, 2023 9:30:07 GMT 12
Lifepof lithium melt apparently rather catch fire or explode.So maybe safer than standard lithium? lifepo4 safety profile is completely different than lithium ion. Electric scooter, bike, car fires are not lifepo4
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Post by sabre on Nov 16, 2023 9:33:51 GMT 12
They will not overheat, and they will not catch on fire, even if punctured. This video of intentionally punctured lifepo4 spewing flame like a flame thrower contradicts your position... youtu.be/07BS6QY3wI8?si=bnM-rdHXsa8vRaG4Fact is, they can overheat, they can burst into flames when punctured. Call me weird but I don't have any plans to intentionally puncture my batteries. Now go find some videos of fla batteries on fire for some ballance. You really are a toxic argumentative troll aren't you. Seriously man you have some major issues. Go get some help.
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Post by em on Nov 16, 2023 9:36:57 GMT 12
If this is the dude you are talking about he’s a muppet . Welding gas right there next to his battery bank and obviously a home install and in his basement for Pete’s sake . The regs here for offgrid installs require a battery compartment away from the house for any battery type . youtu.be/FvUxr4szAV4?si=ypHJbNr29zv1xqMx
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Post by fish on Nov 16, 2023 9:41:51 GMT 12
I really recommend you get a temp gauge. Even the FLA / AGM's need temp compensation for the optimum charging voltage. Can't do that without a temp gauge. The warmer the ambient temp the lower the charge voltage is needed. That and the basic concept of a thermal run-away. As a batt heats up it can take more energy so heats up more, so can take more energy, after a while that energy has no-where to go. Temp probes are a direct plug in for Epevers. Wont be expensive on Aliexpress and will be legit gear. And yes, the Lithium BMS's are deadly for alternators. The whole point of the BMS is to cut off the battery if it gets too much charge. Odds on the alt is going hard out if the batt is getting too much charge. You get an uncontrolled load dump on the alternator which fries it. The alternator is putting out maximum current, and in a milli-second there is no-where for that current to go... boom! About the only way to deal with it is to charge via another battery (like the start) via a DC-DC charger. If the BMS shuts down, the current goes into the start (AGM) and the normal control systems can do a controlled shutdown of the alternator. The issue I couldn't get my head around was acceptable charging current for the start batt. One of the big advantages of Lithium is their high charge current acceptance / fast charging. Up to 100% of the amp/hours (C100). I'm not aware of a traditional batt / start batt that can handle more than 10% of it's capacity. Lead-carbon can handle loads, but it is till max 30%. Fairly sure AGM type start batts can pass through greater current than they accept, but what I couldn't work out was what happens when the lithium is full and not taking charge? How do you get an alternator smart charger to not give the start excessive current? That, and DC-DC chargers with high current start getting very expensive. 10amp to 30amp DC chargers aren't too bad, but much more than that and the price goes up a lot. It appears there is a technical limitation on the current a DC charger can do, so you end up needing two or more, which obviously doubles the cost. That is all just to achieve the fast charge capability of Lithium. That shifts the economics of installing Lithium to a point where it is far better and cheaper to just stick with conventional tech and plan to replace it every 5 years or so. While it wouldn't hurt to have a temp sensor, from what I have read, thermal runaway is almost impossible with lifepo4 even when they have artifially tried to trigger them. You would have to seriously abuse them to have any issues especially in a modest system like mine. You have obviously had a good suss of the other issues involved so clearly know a lot more than me. Personally if I was adding lifepo4 to an existing system with an alternator/wind turbine, I would make it stand alone with just solar as the charge source. I think most people once they go lifepo4 will be kicking themselves they didn't do it earlier. When I first got mine I hooked it up to our 7kg washing machine and put a full load through. At the end of the cycle I literally heard the battery yawn and go back to sleep. From memory resting voltage was 0.2 less than when it started. I then thought right lets hook you up to the deep freeze in the garage. Everytime I walked past over the next couple of days I could hear the battery snigger and mutter something about what a cushy life it had. The tech is seriously good and is 100years ahead of fla etc The washing machine will be the batt's high current output ability (I assume you are using an inverter?). The low voltage drop is because it has a completely flat voltage profile between about 98% charged and about 20% Domestic chest freezers actually have surprisingly low power usage. Mine has a 250w compressor I think, easily in the range of running it off a simple solar or cheap generator. Any good capacity battery would hardly notice a chest freezer running of it (the exception being when you drop a whole beast in it and freeze it down). A good lithium certainly wouldn't even notice a chest freezer running off it. I can't explain why you are hearing voices from your battery though. Perhaps that is something to do with what you are growing in the hydroponics, or maybe the herb garden?
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Post by fish on Nov 16, 2023 9:54:08 GMT 12
If this is the dude you are talking about he’s a muppet . Welding gas right there next to his battery bank and obviously a home install and in his basement for Pete’s sake . The regs here for offgrid installs require a battery compartment away from the house for any battery type . youtu.be/FvUxr4szAV4?si=ypHJbNr29zv1xqMxI didn't watch the whole thing (who would waste 27min of their life looking at some guy's burnt out garage). But at 17min he did say the battery voltages were well out of whack an he should have just disconnected them. I.e. he admits he knew of a problem and did not deal with it. This is a classic case of knowing what you don't know. There were 3 batts? One had a completely different voltage. It shows the fire was caused because the charging system is seeing the collective voltage but one batt is at a higher voltage. That high voltage batt would have over-charged, then overheated and started the fire. The next question is why the voltages were different. Possibly some sort of battery fault. I think EM got some cheap lithium batts off Sunnytech and they had different voltages, so he sent them back. That was when I was looking hard at some cheap lithiums from Sunnytech. The cheaper the lithium battery, the high likelihood the cells aren't balanced. If the cells aren't balanced, one can over charge. If it does that enough it can catch fire. Based on EM's experience, I crossed Sunnytech's cheap batteries off my list. I don't think this is a problem with the technology as such. More an aspect of the cost and quality, AND user knowledge. It is a bit pointless blaming the battery for catching fire when you saw a problem and left it. Linking back to 'knowing what you don't know', DIY installers need to understand EVERYTHING about the battery, set up and operation. You aren't allowed to do the 230v installation in your house, but you can do 100amp DC installations... These batteries aren't just chucking in a couple of AA's and having a cold beer.
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