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Post by Mr Stabby on Sept 25, 2020 15:48:35 GMT
If they last longer than six months they will be the only thing to have ever come out of China apart from the Coronavirus which did. I think you will find that most lithium batteries come out of China. Not telephones though- there aren't any telephones in China.
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Post by Telemachus on Sept 25, 2020 20:23:45 GMT
This is quite an interesting article about LFP batteries which tends to reinforce the theory that LFP batteries which get well used are better than ones which only have partial cycles. Some slightly technical parts to the article but it's interesting. iopscience.iop.org/article/10.1149/1945-7111/ab7900One of the problems with oversized battery banks is that they tend to remain close to fully charged, which they don’t like. Hence my system will allow selection of target state of charge, and charging will stop when that is reached. Probably normally 80%, unless we are planning to stop for a few days.
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Post by JohnV on Sept 26, 2020 7:24:11 GMT
interesting posts Nick. A very sophisticated system, it might be worth your while to consider marketing it. (although the problem with that is that unless it is something you enjoy doing, it takes valuable time away from doing the things you do enjoy doing ..... if you follow my meaning )
Like Kris I have sh Mastervolts from James. I was going to get complicated with monitoring etc but as they had been in use for about a year before I had finished designing it, during that time I had been monitoring manually and the greatest total variation in that time was 0.1V (per 12v battery) so I never did build it. I have a very simple undervoltage alarm (set to 25 volts) and depend on the programming of the MPPT to prevent overcharging (as of yet I have not had the need to engine charge them as 1KW of solar has been sufficient during the times when I would be cruising) So far in winter I have had shore power available and when needed have charged them with Vetus chargers set for AGM and as it's a slowish charge rate and easy to keep tabs on, I just switch them off when they are up around 70/75%. My sh LiFePO4's were not more expensive than a half way reasonable set of Pb's of a comparable useable capacity, so any lifespan in excess of 3 years will be a bonus. If they fail in 10 years time and I am (a) still around and (b) sufficiently compos mentis to understand the significance ........ I shall be delighted
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Post by kris on Sept 26, 2020 7:40:18 GMT
John your bank is 24v then ? I intend to use a system similar to yours, charged from solar and battery chargers for a start then I’ll sort out alternator charging later. I’m finally getting them set up, hopefully this next week.
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Post by JohnV on Sept 26, 2020 7:55:52 GMT
John your bank is 24v then ? I intend to use a system similar to yours, charged from solar and battery chargers for a start then I’ll sort out alternator charging later. I’m finally getting them set up, hopefully this next week. Yes that's right Kris, Sabina H is 24v ...... as I have said before, my layout wouldn't suit everybody but it meets my requirements and I like simple answers
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Post by Telemachus on Sept 26, 2020 8:24:39 GMT
interesting posts Nick. A very sophisticated system, it might be worth your while to consider marketing it. (although the problem with that is that unless it is something you enjoy doing, it takes valuable time away from doing the things you do enjoy doing ..... if you follow my meaning )
Like Kris I have sh Mastervolts from James. I was going to get complicated with monitoring etc but as they had been in use for about a year before I had finished designing it, during that time I had been monitoring manually and the greatest total variation in that time was 0.1V (per 12v battery) so I never did build it. I have a very simple undervoltage alarm (set to 25 volts) and depend on the programming of the MPPT to prevent overcharging (as of yet I have not had the need to engine charge them as 1KW of solar has been sufficient during the times when I would be cruising) So far in winter I have had shore power available and when needed have charged them with Vetus chargers set for AGM and as it's a slowish charge rate and easy to keep tabs on, I just switch them off when they are up around 70/75%. My sh LiFePO4's were not more expensive than a half way reasonable set of Pb's of a comparable useable capacity, so any lifespan in excess of 3 years will be a bonus. If they fail in 10 years time and I am (a) still around and (b) sufficiently compos mentis to understand the significance ........ I shall be delighted No I don’t propose to market it, too much hassle and as we know, every boat is different with different equipment. My system has been designed around Mastervolt kit but whilst their Combis are fairly popular, not many people have the Mastershunt battery monitor. There is complexity of design, and complexity of use. My aim is to make the latter the priority (ie making it “fit and forget”), but to achieve that it has to be complex in design. In you case you say “I just switch them off when they are around 70/75%”. That immediately rings alarm bells of “human error” potential, when you get distracted and leave it on by accident.
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Post by Jim on Sept 26, 2020 8:29:48 GMT
interesting posts Nick. A very sophisticated system, it might be worth your while to consider marketing it. (although the problem with that is that unless it is something you enjoy doing, it takes valuable time away from doing the things you do enjoy doing ..... if you follow my meaning )
Like Kris I have sh Mastervolts from James. I was going to get complicated with monitoring etc but as they had been in use for about a year before I had finished designing it, during that time I had been monitoring manually and the greatest total variation in that time was 0.1V (per 12v battery) so I never did build it. I have a very simple undervoltage alarm (set to 25 volts) and depend on the programming of the MPPT to prevent overcharging (as of yet I have not had the need to engine charge them as 1KW of solar has been sufficient during the times when I would be cruising) So far in winter I have had shore power available and when needed have charged them with Vetus chargers set for AGM and as it's a slowish charge rate and easy to keep tabs on, I just switch them off when they are up around 70/75%. My sh LiFePO4's were not more expensive than a half way reasonable set of Pb's of a comparable useable capacity, so any lifespan in excess of 3 years will be a bonus. If they fail in 10 years time and I am (a) still around and (b) sufficiently compos mentis to understand the significance ........ I shall be delighted No I don’t propose to market it, too much hassle and as we know, every boat is different with different equipment. My system has been designed around Mastervolt kit but whilst their Combis are fairly popular, not many people have the Mastershunt battery monitor. There is complexity of design, and complexity of use. My aim is to make the latter the priority (ie making it “fit and forget”), but to achieve that it has to be complex in design. In you case you say “I just switch them off when they are around 70/75%”. That immediately rings alarm bells of “human error” potential, when you get distracted and leave it on by accident. Get them made in China by the container load. naughtyfox is an expert on chinese manufacture and it's benefits, he can advise.
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Post by kris on Sept 26, 2020 9:08:41 GMT
No I don’t propose to market it, too much hassle and as we know, every boat is different with different equipment. My system has been designed around Mastervolt kit but whilst their Combis are fairly popular, not many people have the Mastershunt battery monitor. There is complexity of design, and complexity of use. My aim is to make the latter the priority (ie making it “fit and forget”), but to achieve that it has to be complex in design. In you case you say “I just switch them off when they are around 70/75%”. That immediately rings alarm bells of “human error” potential, when you get distracted and leave it on by accident. Get them made in China by the container load. naughtyfox is an expert on chinese manufacture and it's benefits, he can advise. The Chinese company would then rip off the design and flood the market with its “cheap copies.”
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Post by duncan on Sept 26, 2020 9:30:24 GMT
interesting posts Nick. A very sophisticated system, it might be worth your while to consider marketing it. (although the problem with that is that unless it is something you enjoy doing, it takes valuable time away from doing the things you do enjoy doing ..... if you follow my meaning )
Like Kris I have sh Mastervolts from James. I was going to get complicated with monitoring etc but as they had been in use for about a year before I had finished designing it, during that time I had been monitoring manually and the greatest total variation in that time was 0.1V (per 12v battery) so I never did build it. I have a very simple undervoltage alarm (set to 25 volts) and depend on the programming of the MPPT to prevent overcharging (as of yet I have not had the need to engine charge them as 1KW of solar has been sufficient during the times when I would be cruising) So far in winter I have had shore power available and when needed have charged them with Vetus chargers set for AGM and as it's a slowish charge rate and easy to keep tabs on, I just switch them off when they are up around 70/75%. My sh LiFePO4's were not more expensive than a half way reasonable set of Pb's of a comparable useable capacity, so any lifespan in excess of 3 years will be a bonus. If they fail in 10 years time and I am (a) still around and (b) sufficiently compos mentis to understand the significance ........ I shall be delighted No I don’t propose to market it, too much hassle and as we know, every boat is different with different equipment. My system has been designed around Mastervolt kit but whilst their Combis are fairly popular, not many people have the Mastershunt battery monitor. There is complexity of design, and complexity of use. My aim is to make the latter the priority (ie making it “fit and forget”), but to achieve that it has to be complex in design. In you case you say “I just switch them off when they are around 70/75%”. That immediately rings alarm bells of “human error” potential, when you get distracted and leave it on by accident. Should you ever want to sell Telemachus at sometime in the future, presumably the system needs to be such that a prospective new owner would be able to look after.
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Post by Telemachus on Sept 26, 2020 10:38:30 GMT
No I don’t propose to market it, too much hassle and as we know, every boat is different with different equipment. My system has been designed around Mastervolt kit but whilst their Combis are fairly popular, not many people have the Mastershunt battery monitor. There is complexity of design, and complexity of use. My aim is to make the latter the priority (ie making it “fit and forget”), but to achieve that it has to be complex in design. In you case you say “I just switch them off when they are around 70/75%”. That immediately rings alarm bells of “human error” potential, when you get distracted and leave it on by accident. Should you ever want to sell Telemachus at sometime in the future, presumably the system needs to be such that a prospective new owner would be able to look after. Up to a point maybe, but resellability has never been a consideration with our boat. A boat is for life, not just for Christmas! Hence the Empirbus dc distribution and control system which is built into the boat and totally beyond any marine electrician that I can think of. By comparison, fitting Li batteries is easily reversible. But it does of course have to be usable by Jeff when I’m not on the boat. In normal operation there will just be a charge rate switch (fast or slow, normally slow) and a target SoC switch normally left on 80%, but selectable to 100% if planning to moor for a few days, or 50% for when in the marina.
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Post by JohnV on Sept 27, 2020 8:31:32 GMT
interesting posts Nick. A very sophisticated system, it might be worth your while to consider marketing it. (although the problem with that is that unless it is something you enjoy doing, it takes valuable time away from doing the things you do enjoy doing ..... if you follow my meaning )
Like Kris I have sh Mastervolts from James. I was going to get complicated with monitoring etc but as they had been in use for about a year before I had finished designing it, during that time I had been monitoring manually and the greatest total variation in that time was 0.1V (per 12v battery) so I never did build it. I have a very simple undervoltage alarm (set to 25 volts) and depend on the programming of the MPPT to prevent overcharging (as of yet I have not had the need to engine charge them as 1KW of solar has been sufficient during the times when I would be cruising) So far in winter I have had shore power available and when needed have charged them with Vetus chargers set for AGM and as it's a slowish charge rate and easy to keep tabs on, I just switch them off when they are up around 70/75%. My sh LiFePO4's were not more expensive than a half way reasonable set of Pb's of a comparable useable capacity, so any lifespan in excess of 3 years will be a bonus. If they fail in 10 years time and I am (a) still around and (b) sufficiently compos mentis to understand the significance ........ I shall be delighted No I don’t propose to market it, too much hassle and as we know, every boat is different with different equipment. My system has been designed around Mastervolt kit but whilst their Combis are fairly popular, not many people have the Mastershunt battery monitor. There is complexity of design, and complexity of use. My aim is to make the latter the priority (ie making it “fit and forget”), but to achieve that it has to be complex in design. In you case you say “I just switch them off when they are around 70/75%”. That immediately rings alarm bells of “human error” potential, when you get distracted and leave it on by accident.comparitively slow charge rate on a large bank gives a very wide window for switching them off .... on top of that the charger boost is to 28.2V then drops to a 26.5V float so even if forgotten, damage unlikely
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Post by Deleted on Sept 27, 2020 17:05:57 GMT
Like Kris I have sh Mastervolts from James. I thought you had Valence batteries John.
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Post by kris on Sept 27, 2020 17:10:56 GMT
Like Kris I have sh Mastervolts from James. I thought you had Valence batteries John. As far as o know he has.
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Post by Deleted on Sept 27, 2020 17:29:14 GMT
Maybe it's an age thing.
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Post by kris on Oct 1, 2020 8:40:23 GMT
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