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Tom and Bex

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Everything posted by Tom and Bex

  1. We hadn't done any planning for thiis year yet either, but most of our planning trends to be last minute and varies depending how energetic the crew are feeling on Friday night! This was also possibly going to be our last year for a bit, as Lily's (hopefully!) starting school in September. The thought of leaving Lapworth at 3.30pm Friday and getting to our start location doesn't sound the best preparations for the challenge! No doubt we'll find a way to be there next year now though - I've already booked the time off work!
  2. A big thanks to the organisers of this event and the hard work they and the teams have put in. Congratulations to Indigo Dreamers for their win. Really enjoyed following the event, and enjoyed reading the cruise logs as and when I had time between 12hr shifts at work. Enjoyed reading about the history and stories of the people teams met along the way, along with the historical facts and descriptions of the BCN in times past. Particularly enjoyed some of the old photos, several that I haven't seem before so thanks for that. Found it fascinating trying to work out where teams were at times in their logs, and working out the route of some of the old branches was interesting. It's had me digging out and going through my collection of BCN books again! Thanks again. Time already booked off for next year's actual challenge and hope to see some of you there!
  3. Enjoying following this and reading all your virtual cruising logs between jobs at work. Particularly enjoy seeing all the photos in the logs. Is there any way for non participants to see the daily quiz and challenge? Even if only at end of day or even end of challenge? Keep up all the hard work!
  4. Not jabsco, but ours went through a stage of occasionally doing that (once every 6 weeks or so). Stripping it down found nothing wrong at all. Power getting to the motor fine. Eventually found that a quick burst of reverse power applied directly to the motor connection worked every time. Certainly nothing to lose trying before you commit to dismantling (not a pleasant task!). Hasn't done it for 6 months or so now (frantically finds as much wood to touch as possible!).
  5. I shall be following this challenge with interest and hope the rules abs scoring will be in public domain. Unfortunately won't be entering. 1st BCN challenge we'll have missed in 8 years? Working that week and with volume of calls increasing, won't have time required to participate. Great idea though and good luck to all the teams.
  6. Mine came reasonably well balanced from Jeremy, but still needed more (and in initial installation, discovered they still weren't balanced enough). Definitely worth taking the tune to get initial balancing right I didn't have any special equipment, but followed the ideas on the http://nordkyndesign.com/ website, using a standard 12v battery charger. Think I checked iindividual cell voltages, got them as close as possible, then connected in parallel, and charged to 3.65v using my 12v charger, bit with very careful CONTINUOUS monitoring. That did rely on using charger via inverter and existing batteries though.
  7. I know it was stopped being supported since time ago. Can't see the risk though, no sensitive information on it, and not used for banking etc. One big advantage for occasional use is the fact it DOESN'T keep nagging for updates every time you turn it on, that then take an age on the slow connection wer have. In fact it works quite well, boots up as quickly as a windows machine can, and then just works! As an aside, some of our computers at work still run XP? Probably comes under the government exemption though!
  8. Still running XP in my old laptop. Working well? Use it for running car diagnostic software and workshop manual. Also use for Water Explorer's Navygator software for recording trips when we go boating, and occasional web browsing using Firefox. Sure there's some other obscure software I use on it as well, and seem to remember using it for completing BCN Challenge log last year! Why upgrade for the sake of it when what you have still does the job well? What benefit would I gain from upgrading to a newer machine other than a whole lot of hassle?
  9. Sounds interesting! Looking forward to more details - not sure I can muster a crew though, but always wanted to do the challenge single handed...
  10. @David Mack I'd be interested in what panel you've got. Looks much more slimline than mine! We're very happy with our system. On sunny summer days gets plenty hot enough for laundry, showers etc, and provides useful initial heating on sunny spring and autumn days. No antifreeze in our system. We remove roof panel during winter, and just left with 2 pipe stubs that are capped off. Could probably be made more efficient with better pipe insulation. Initially looked at the standard thermal panels that use glass vacuum tubes, but decided they were too fragile for boat use so went with flat plate collector. More expensive, and less efficient, but in my opinion, better for boat use. Also most glass tube panels are not suitable for mounting flat - something to be aware of for boats.
  11. Working again, thank you. I think those that criticise the forum software and think other software would be more reliable obviously don't use other similar sized forums much! All the other forums I use have occasional problems, I think on the whole CWDF has a very good uptime compared to some others I use.
  12. As above, Lyons and Swallow Cruisers. There's also Waring Green Wharf. Whether any are open at present I couldn't say, definitely phone ahead. Suspect Lyons would be cheapest, followed by Swallow. I know Warings Green only do 60/40 split, not sure about swallow, but fairly sure Lyons let you choose.
  13. There's several liveaboard boaters moored towpath side by the bridge, I wonder if they heard or saw anything? Would usually be a busy spot with a pub at each end of the moorings, not at present though.
  14. Do we know if the tree(s) actually dangerous though? OP just asked who is responsible for safe maintenance of overhanging trees not that it's actually dangerous. My experience is CRT will be completely uninterested if it's just the usual overhanging offside vegetation, and will only take an interest if it's actually dangerous and likely to cause serious damage or block the canal.
  15. I'm guessing this happened overnight. All looked secure when we passed to turn round yesterday lunchtime. Must be a high percentage of all the boats there? Gutting for ther owners, and worrying for other boaters moored locally.
  16. Thanks for the replies. Punt taken, will look to buy a new pump on next pay day, just don't like buying new when things can be repaired. I suppose that would give me time to investigate the old one at leisure and keep as a spare if repairable. Currently only leaking a bit, and now have drip tray underneath. Obviously been leaking for some time though - that will teach me to check theses things more often!
  17. We've got a jabsco par max 3 fresh water pump, that's started leaking from what looks like a small cover plate on the head (see photos). Any idea what this bit is for, and what I need to buy to repair? The repair kits I've found, don't seem to include anything that looks like it would fix this. I believe there is usually a pressure switch under the blue cover that I've removed for the 2nd pic, but as we have a separate pressure switch, it's not present on this pump. Reluctant to start to strip it down until I have an idea what to use to repair it! Cheers
  18. Not complicating things, if anything simplifying it by using separate alternator reg together with simple modification to alternator. Always feels a bit of a wrong to me switching high currents instead of controlling those currents at source, but lots do it with no problems. Depends what you mean by split charge. The way I see it working is the alternator(s) are permanently connected to the lead acid start battery, and the lithiums are connected to the LA start battery by a simple high power relay until full charge is reached, then the relay is simply switched off (by whatever method is decided on). As it's a straightforward relay, it could be easily controlled by a Victron BMV, or the voltage control board linked to earlier. If power taken from ignition switch, then would only be activated when ignition is on. If using the voltage control board, would suggest connecting this to sense voltage from lead acid side, otherwise you risk it cycling. If sensing voltage from lithiums, then charge gets disconnected at set voltage point, voltage falls, board reconnects etc. If sensing start battery voltage, charge gets disconnected at set point, voltage on lead acid rises to alternator regulated voltage, relay stays disconnected until engine switched off. Id also consider a manual switch to force the relay on as we have (relay usually controlled from alternator controller). Maybe a brightly illuminated switch so you couldn't forget it! This would enable manual charging beyond the point it would usually terminate charge, option for emergency charging if control of relay fails, and importantly, option for starting engine from lithiums if start battery fails (we've used ours for this a few times when start battery failed on us). Overheating of alternator not to be underestimated. I thought ours would be fine, but it lasted less than 8 months before burning rotor out. I think MP had problems as well. Cheap enough to replace an a127, but might not be for you depending on alternator model. We've used the settings on our alternator controller to reduce max charge from 90-100a, down to 70-80a (when both alternators connected), but only time will tell if this is enough. Can't see any long term problem to alternator or lead acid start battery if using as a dump load on regular basis. Not sure how long the relay would last though, guess it would depend on relay specs and charge current at time of disconnection. We don't have quite the same level of protection! We (only!) rely on 3 protection levels! Firstly our charge sources are set not to overcharge in the first place. Secondly we have the isdt bc-8s for monitoring cell voltages and providing alarms for cell over and under voltage, and cell differential voltage. Thirdly we have the bms as our last ditch protection, that cuts loads if a cell goes under 2.5v (reconnects at 3.0v) and cuts charge sources if a cell goes over 3.8v (reconnects at 3.4v). Finally, as a bit of an extra discharge protection, we have low soc alarm on the BMV set to 20%. The low soc alarm is the only protection that's activated on our setup, and that's because it has been so maintenance free, we forgot they would need charging when solar stopped providing our daily usage in October! The bms has never activated the high or low cut except in testing. We did have some cell differential voltage alarms initially when pushing charging to 100%, however I think that was down to insufficient balancing and being too impatient to get the cells installed! Following further balancing, and now following the addition of a battery balancer, we've had noi further issues.
  19. Nick's option is much a more elegant solution in my mind. Sounds similar to what our alternator controller does, but more integrated with the rest of his system. We have twin 70A alternators. With very flat lead acid we never saw more than 50A. With the lithiums that could easily be 100A (and burnt out alternator in a few months use!).
  20. Controller I use now only available for around £500 I'm afraid. Whoops my mistake! Surprised no-one else picked up on that! I think it integrates with you're other victron stuff, but as it's the only Victron item I own I can't confirm! Look at the graph below. You can clearly see the voltage is only rising very slowly until right at the end of charge, when it climbs very quickly. The point it starts to climb is called the knee. This is why balancing is important. Imagine you're charging at 14.0v. If not balanced, then one cell could easily climb to 4.1v, whilst the others are still at 3.3v. That's why monitoring cell voltages is so important (as your bms does) and why just monitoring total voltage is not really enough. Avoiding the knee on both charge and discharge, reduces this risk considerably. That sounds fine. Not being familiar with Victron kit I wasn't aware their MPPT controllers had that option. Just a word of warning - be very careful of default lifepo4 settings. Most of the default charge voltage settings I've seen are much to high. As you say, the MPPT can have custom settings such that the bms never has to activate the emergency disconnect. If relying on the bms then you'll be pushing the cells into their upper limit each time you charge. Charge sources should be set not to overcharge under normal operating conditions. The bms high voltage cut is to prevent an overcharge from occurring if the charge source regulation fails (which can happen - particularly with alternators). Not something that needs sorting immediately, but need to have an idea how you plan to manage alternator charging going forward. No need for voltage board to control latching relay, keep Tyco relay for bms emergency control, and use normal 180A relay for alternator control, linked to voltage board. If voltage board connected to lead acid side, then once set voltage point is reached, it will cut parallel relay and voltage will rise until engine switched off again. As above, Tyco relay is in charge side, but never activates in normal use as not a control relay, only there to prevent damage if charge regulation fails. That's one option. Ot a standalone regulator (disabling internal alternator regulator). Not difficult on a127 and probably fairly easy on others, just need access to one of the brushes and to disconnect/disable internal regulator. No problem at all for alternator. Also no need for expensive latching relay or motorised switch, normal split charge relay more than adequate. Probably not as difficult as you think to modify alternator to switch regulator off (depending on alternator type). Definitely the more elegant way rather than using lead acid dump load. Your bms would then provide for the emergency backup disconnect. Yes of it activated you risk alternator damage, but by it's nature, something would have already failed to get to that point anyway . You're looking at modifying the alternator to use external regulator again by this point. You know it makes sense!
  21. Only using the Arduino based alternator controller that Dr Bob alluded to earlier. This controls all alternator charging of the lithiums including switching to float when fully charged (based on voltage and tail current). Only available commercially now at c£500, but as originally open source, design and code still available with some searching (pm if interested). Not given much thought to how I'd do alternator charging now, but probably be based on a lower (or adjustable) voltage regulator if available, or simply on cut charge when set voltage is reached using something like the Amazon voltage board linked to. Nick's design looks promising as well In series the current stays the same! 3 cells in parallel would give up to 600A @3.2v, 4 of those in series would give up to 600A at 12v (nominal) Jeremy would bre talking about 200A per cell. EV use demands very high peak discharge rates, and the problem with some cells as they age is the voltage drops too much under heavy loads >200A. If used at much lower charge and discharge rates voltage drop is negligible, and capacity remains close to badge capacity. Jeremy said my cells had exactly the same issue. We've had no problem with them in use, and have used a measured 280Ah which is not bad from 160ah cells in 2p4s configuration. Probably could have got more if pushed to the limit of charge and discharge, bit don't see the point of pushing boundaries for the sake of it. As above, cell voltage would dip below bms cut off and (hopefully!) bms would trigger the low voltage relay. I think most on here are using the Victron BMV for monitoring. I know @Dr Bob does, although he doesn't seem to think the SOC is very accurate. We use it, and with the settings I've used the soc seems to remain fairly accurate until we re-sync it around every 3 months or so. Maybe slightly pessimistic, but not enough to cause problems over a 3 month period, and would rather that than give opportunistic readings. On our machine you can also set to cold on the temperature dial, which performs no heating at all. We have the mixer set to hot for the wash cycle, but cold for the rinse to reduce creases. Personally I think the bms will be more reliable than the low voltage buzzers, I've seen very mixed reviews about their reliability and accuracy. If you want additional safeguard personally I'd recommend the ISDT bc-8s if you can still get it. Basic display, but reliable and simple to use, with individual cell voltages, and (loud!) customisable high and low cell voltage alarm. This has been supercded with the bg-8s which despite bigger full colour display and more features, doesn't seem to be as suitable (think @Dr Bob has both - maybe he can advise?). Top balancing is definitely the recommended way for domestic use. Not possible to fo both. No need to be too conservative. Wer usually run ours between 20% and 90%, with occasional charging to 100%. Generally if cruising we seem to charge to around 95%, general opinion seems to be charging to 100% and then using them is not really an issue, it's the storing at 100% that causes long term deterioration. Problem comes with determining when 100% is reached, and ensuring all cells reach it at the same time without one of them going into the upper voltage knee (hence top balancing). Bottom balancing tends to find favour in ev use due to the high currents used, and thr need to ensure all cells are performing equally when drawing high current at low soc, thus ensuring maximum range is achievable. Ideally when supplying domestic loads, you'll not be pushing the bottom limit! Still not convinced on this memory effect. I've read anecdotal reports of it, but no explanation for it, and not seem any actual data to back it up. I think you'd really struggle to run any welder from the typical inverter found on boats. As above, you'll find the BMV very useful tool. We use ours purely for monitoring, and the bms for providing the high and low cell voltage protection. The fact your bms provides support for the Tyco relays directly is a definite bonus! I'd still recommend using the bms to provide a high voltage cut as an emergency back up in case of fault. How does the MPPT work to provide a low temp cut? Make sure you're not confusing voltage temperature compensation for low temp protection, LA's need higher voltage at low temperatures - the exact opposite of what you need for lithiums! t's only charging to be concerned about low temp, but if inside like ours are, I don't think it very likely anyway. You shouldn't really rely on the bms for everyday charge control. Bms should be last ditch protection if the other systems fail! You could use the voltage board, linked to a relay for providing charge control. If the relay was only powered when ignition on then no problem using normal relay as no ongoing power drain. Alternatively use a relay to cut the alternator regulator directly, (very easy to do with a127 alternator) then no need for lead acid batteries at all! That's the type of board I've referred to above. Very difficult to find any devices giving direct control of Tyco relay, you'd need an additional control circuit @MoominPapa posted about a simple one he designed I think. I use a BEP motorised switch on the load side controlled by the bms, and a Tyco relay in the charge side, again controlled by the bms, but via a control circuit as my bms does not support direct control of the Tyco relays. My bms controls both. The BMV is used purely for monitoring, and the alternator controller is purely for controlling alternator charging, including controlling split charge relay for connecting both alternators to lithium bank during bulk charging. As mentioned above, don't recommend using bms as main charging control. Leaning towards voltage control board for cutting charging at set voltage point, say 14.0v. This would probably result in charge terminating at around 80-90%, but would depend on alternator output, and wouldn't be exactly the same each time. Might require experimenting to find best voltage point for your system, and probably an override to enable manual (carefully monitored!) charging to 100% on occasions. Alternatively the BMV could be used to control a relay based on soc, so cutting charging when 100% is reached based on voltage and tail current settings in BMV. Actually, thinking about it, thiis might be the best option for alternator charge control, particularly if used with a lower voltage regulator.
  22. I think in reality you're unlikely to get through many 200A fuses. Don't forget fuses won't blow the moment you exceed 200A, depending on the fuse you will probably have to exceed 200A by quite a bit or for some time before it blows. We have 150A fuse, and not blown it yet, even starting engine from our lithium batteries several times when the starter battery failed. I don't think you need an additional low voltage cut off. The bms should provide that based on cell voltage, not sure much benefit to be gained by having an additional cut off based on system voltage. I do like the look of that bms so will be interested to hear how you get on with it. I seem to recall reading that nearly all panels have built in bypass diodes. All the ones we've had seem to. Yes you lose the output from the one panel that's shaded, but still get most of the output from the others. Agree it might not work so well with a combination series parallel configuration, not something if thought about before. Another reason to stick with series connection if the controller can cope with maximum open circuit voltage.
  23. I find when charging at 70-90A via alternator, then with our setup, the batteries are around 80-85% charged when the voltage hits 14.0v, and if we want to charge them higher, we continue in constant voltage mode. Not sure the same could be relied on with solar due to the variability of it I suspect you'll find that he's talking about the current draw per individual cell, so with 3 cells in series then you're looking at limit of 600A! Even with big inverter I doubt you'd be able to get near that! Remember for ev use then those figures are easily achievable, and much higher figures are seen regularly under acceleration, really shows what these batteries are capable of when new. No memory effect to worry about. Only real reason to get to 100% is to re-sync battery monitor. What monitoring are you planning for soc? Does the bms give this info? If so need to read instructions to see if they recommend charging to 100% every so often to re-sync it. If using the batteries then they'll not be stored at 100% overnight anyway. No reason to deliberately discharge them, just use as normal. I was under the impression that the water heating was the bit that consumes a lot of power, which is why I bought a washing machine that didn't do that. How can I calculate how large an inverter in VA I need to power this washing machine, then? I can't get a straight answer on peak W load, but it says it uses 1.05kW per "cycle", around an hour. So I guessed that the peak usage is around 1500W-2000W with the heating on. We use our washing machine quite happily off our 1500w inverter and it doesn't get near the limit. Ours has control to set wash temperature that overrides program setting - we leave this permanently set to cold, and have it connected via mixer valve so it fills with hot water for the wash, and we switch mixer valve back to cold for rinses (if we remember!) Similarly, sometimes run 1200w iron and hair drier from our 1500w inverter (not both at same time!). As to kettle, we don't have electric kettle, but do sometimes run electric soup maker (1500w) from inverter. These batteries have transformed our electric usage, and we happily run stuff we wouldn't have dreamed of running from the batteries before.
  24. But the limit is 17T Maximum Gross Weight so would apply to that vehicle regardless of if it was empty or loaded. Blatantly breaking the law, as well as incredibly irresponsible.
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