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MoominPapa

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Everything posted by MoominPapa

  1. This post cannot be displayed because it is in a forum which requires at least 10 posts to view.
  2. Saw the first hireboat steerer wearing a captain's hat yesterday. Spring has spung. MP.
  3. Almost all of the traditional boats around now are from the last generation of working boats, built for the "sunset days". For most of the carrying life of the canals, cargo boats were wooden, and propelled by a horse. There are very few of those left. MP.
  4. If you decide to sell, may be interested, depending on price. PM me if so. MP.
  5. This post cannot be displayed because it is in a forum which requires at least 10 posts to view.
  6. He explicitly says he's not; way beyond his price range. MP.
  7. A convoy of three Alvechurch hireboats came past us today at Henhull........ MP.
  8. In County Wicklow, Franklin definitely beat Eunice. Our power went out at about 3.30 and was not back when we left the house to drive to the ferry this morning. I really felt for the guys fixing it, every few hours they'd close the breakers and the power would come back for a few seconds, only to be trip with some new fault. Three Atlantic storms in a week has been a rough welcome to Ireland, and an extended power cut in a house where everything needs electricity, including the water supply, was a bit of a shock. We have a backup plan with camping stoves, generator, etc but none of that stuff has arrived yet. Thankfully by this afternoon the Irish sea had calmed down a lot, and the crossing was not too lumpy. All the trucks on the car deck were chained down. MP.
  9. Our ferry back from Dublin this afternoon is cancelled. Rebooked tomorrow, expecting a rough crossing. MP.
  10. I trust the BMS's idea of SOC implicitly now. When we're not using the engine I can know with confidence how many days are left before we need to move or run the genny. MP.
  11. I've left the balancing to BMS for the past year, at least and they're all quite happy. Sometime before Christmas 2020 I added a feature to the BMS to keep a running total of charge and discharge. The two values are now around 25,000Ah and pretty similar, as you'd hope. Given that someone mentioned manufacturers hopes for this metric in the MAh range upthread, I'm hoping my cells have plenty of life left. They certainly haven'y lost any noticable capacity after three years. MP.
  12. I believe you, but in that case a suitable ballast resistor would stay cool too. If has the same effect it has the same resistance and dissipates the same amount of power. BTW have you actually calculated what the power dissipation is? I can't help thinking that all this effect with B2Bs and bits of wire are avoiding the real solution, which is properly implemented alternator regulator. MP.
  13. The long wire is a ballast resistance and will produce heat. I suggest not bundling it up or installing is in enclosed compartments or touching flamable material. MP.
  14. This is going to be our baptism in the new pad halfway up a hill in County Wicklow. Current predictions are 100kmh gusts. I guess we'll see if the roof stays on and the power stays on. If the power goes off we do have a load of logs stacked up outside to keep warm. They're being kept dry by a tarp though, so may end up soaked if that sets off down the field. No power means no water (well) and no cooking, as we don't have the backup camping stove yet. At least the previous snow warning is looking less likely, though we may still be kept here by fallen trees until the farmers get around to clearing them. The wind turbines on the hill above us were shut down during the worst gusts today. I imagine that will happen again for Eunice. MP.
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  16. Also the world's most gnarly soldering iron. MP.
  17. In an A127 of indeterminate age, I doubt it. Modern designs, very likely. MP.
  18. Don't confuse the regulator and the diode pack; they are physically and electrically distinct. The regulator (and the dedicated diodes that power it) dissipate relatively little power, and the ambient temperature inside the altenator case is not crazy high for silicon transistors and modern resistors. The problem is the diodes that are carrying the full alternator output. As Jen points out the junctions of those are dissipating a lot of power and are likely the highest point temperatures anywhere in the alt by some margin. MP.
  19. A smart regulator is a good idea, as long as it doesn't have to throttle things too much. Remote diodes are also a good idea, which I've considered (not dangling them in the canal!). Implementation is a bit of a pain, not least providing three high current terminals on the back of the alternator, and, in my installation, a fairly long run of three phase to get to a position suitable for diodes, heatsink and a fan. MP.
  20. For an A127, certainly. The diodes and heatsinks are at the back, just behind the cooling slots, so an air duster would work quite well. Just don't shove anything conductive in there. MP.
  21. They are mounted on reasonably substantial heatsinks made of ~5mm thick metal, probably steel which form one of the diode connections. There are two heatsinks, one bolted the case forming the common for all the negative diodes, and one isolated from the case which is the common for all the positive ones. MP.
  22. Alternators on boats work hard, and alternators on boats with lithium batteries work harder. I have a couple of failed alternators on board. One failed before we got lithium batteries and one after. They are both 70A A127s. Since the second failure caused me to have install the brand-new Ebay sourced spare that I carried, I thought I'd look at the two failures with the aim of building one functional unit to take over the role as a spare. In both cases the only fault was a failed diode. One was open circuit and one short circuit. I wondered if cooked stator windings might be a problem, but both stators looked fine and metered out OK. I'd already bought a new diode module on Ebay for £12 and fitting that is pretty trivial, as long as you have a BIG soldering iron. The sort your Grandad had, not a 15W tidler suitable for doing electronics. What was noticeable about both units was that the cooling air path around the diodes was clogged with dust and fluff. I suspect if I'd stuck with my good intentions and dismantled and cleaned them once a year, they would not have failed. So, lessons learned. A127s survive maximum output for long periods pretty well, and when they do fail, it's normally the diodes. When they fail, they are easy and cheap to repair. Keeping them free from fluff and dust will probably stave off diode failure. I have a good spare now, but I think I'll probably carry a spare diode pack too. There's good access with the alternator installed on the engine, and it's actually easy to remove the back half of the case and stator whilst leaving the front half, rotor and belt in place. That allows a quick change of the diodes with very little dismantling of the installation. It also saves having to undo the pulley nut to move the pulley to a new alternator, which is the most difficult part of a swap. MP.
  23. I used the same term the OP did, so any credit is due to them. MP.
  24. I've installed a Hybrid Lithium system. It involved adding a high current Schotky diode and a bistable contactor into the charge wiring, changing the alternator regulator to one which could be computer controlled, a PCB full of electronics and an Arduino running 2500 lines of code I wrote. The resulting system is stable and foolproof and I'd be happy for it to be used on my boat by other people. I would not sell copies of it: that would require extensive testing with different charge sources and different batteries. Without casting aspersions, if you can find a marine electrical fitter capable of replicating what I did, I'd be very surprised. The skill-sets are rather different. MP
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