Dr Bob

Getting help for MH issues from the NHS is a nightmare. I feel for the lady. She needs all the support we can give her.

Exactly

Well, what a great response. Thanks to all who took the time to give me your views. Very much appreciated. From all of this, the 'chilling out' aspect comes through loud and clear and I now understand who has right of way and how the experts would do it. Sea Dog's comment caught my attention. Fully agree with the different end of the telescope. We've only been at it a month now but the number of boats you give way to - to go through a simple bridge- and they dither about even when you signal them through - and then crawl through. You wish they would just put their foot down. Ray T, love the comment on belt, fists and windlass! I can just see it. Very interested in the replies to Hudds Lads question. Keep 'em coming!

We are new to the canals so wanted to get some views on "who goes first" and what we did wrong last sunday. We were out on the GU with the kids and grandkids heading from Braunston towards Norton Junct where we winded to go back to Braunston. We went under bridge 10 and turned into the Leicester arm....and then reversed in the direction of Buckby top lock ready to go forward back under bridge 10 back towards the tunnel. No other boats in sight. Unfortunately we picked up a plastic bag on the prop so came into the north bank of the canal a few yards to the east of the Leicester arm. Cleared the rubbish and then started off. Problem now was that we could see 3 boats coming down from the Braunston direction, spaced quite a bit apart. We were nearer the bridge 10 than the first boat, but gave him right of way as he was moving. He wanted to turn left up the Leicester arm so we reversed a bit to let him through - my fault, I should have seen that one coming and not covered his exit up the Leicester bit. We then moved forward to go under bridge 10 but the second boat was coming fast although again we were nearer and now covering the turn to the Leicester arm. We therefore stayed put and let him come through and although we were across the junction he didnt signal he was turning north until through the bridge, therefore forcing us to reverse again. Ok - again we should have held back. What I am really p**sed with is the 3rd boat then put a lot of revs on and stormed through the bridge and again turned north when it had to be clear to him that we had been waiting and we were far nearer to the bridge than him and across his exit. Tailgating seemed to be the thing of the day. What should we have done? It was a very busy day with lots of boats about .....and some going very slowly. On the way back we caught up with a couple boats training some teenagers. We were 2nd in the queue behind them. Now we dont tend to go that fast and seem to settle on 1200 revs (which is circa 3.5 mph if the water is deep enough) when it is clear . We were forced to go at 700revs and cycle between being in forward gear and neutral......an no, it wasnt past moored boats, it was the 2 miles before and IN the Braunston tunnel. We are 63 ft and the boat steers a lot easier if we have 'some' revs on. How do you guys react to situations like this? I've got no problem slowing down and going slowly but when its windy, a bit of steerage is very useful. Keen to hear the wisdom of the forum.

Fully agree. We did our ocean sailing over the years including Norway, Scotland etc but have given up as it is too strenuous trying to reef a 40ft boat in a force 5. We now love our NB and have been so lucky to have tried both. One is not better than the other. Both are completely different experiences. ......and Richard, I guess you were the 'Richard' from Manchester with the Blue and White spinnaker avatar on the YBW forum? We were a year behind you going down to Lagos and I always looked forward to your posts on YBW. I knew you got to Malta but then wondered where you had gone. We were down that way 2008-12.

I wasnt thinking of testing to destruction....and I wasnt thinking of testing thousands of batteries....just a couple. I also wasnt thinking of an algorithm. For that you need lots of data - and using thousands of batteries - as his model was a global model that had to work for everyone. I was thinking of the newer types of model predictions - viz Topology that uses pattern matching or other advanced techniques. The technique is to get one or two models working on one or two installations during normal running with a limited set of variable inputs and a defined set of fixed inputs. If a relationship can be set up between data in one set up, then the model can be expanded one by one to introduce new training sets. The world has moved on. The amount of data you need is far less. Please stop reading now if this is boring you. Let me give you an example of pattern matching models that many of you may have an interest in. The refining industry make gasoline and sell it to us motorists. They sell to a standard MON/RON value (Motor Octane Number, Research Octane Number). So I buy petrol at RON95. This is tested by an engine test which takes 24 hrs and is accurate to +/- 1 unit. The refineries therefore should make it made to RON96 so that every drop is over RON95 when they sell it ( I think I have RON and MON the right way round) - similar to shops selling a bag of sugar of 1Kg, they always put a little more in to keep them at 1Kg minimum. That 1 unit of RON 'give away' costs refineries over £2M per year. We developed a model to do this on line using Near Infrared Technology (NIR). At one refinery we tested the output from gasoline blending to collect NIR spectra - that were to the naked eye just a wiggley line - and tested a number of Engine tests which were inherently inaccurate. People had tried for years to do this via regression modelling and trying to come up with Algorithms to do it. They never worked. The input data kept changing and the linear regression models although accurate when the new feed was in the training set range, were useless when outside the range. That is akin to having a model based on say a 500Ahr battery bank and then using the model on a 400Ahr bank. The topology method overcame this and it was possible to come up with a unique system that could cover all feeds with only a little effort with new tests and model validation. Now when you go to a petrol station, you tend to get 1unit of RON less as there is no give away as the NIR test is accurate to within .05% rather than the 1% of the engine test. If you are into Diesel not petrol, then we did the same for Cetane number in Diesel. Have you ever noticed how sometimes you get a tank of bad petrol (or diesel). Sometimes it is this RON giveaway. Sometimes it is how much Butane the refinery puts in the petrol!!! ....but not all refineries are using this technology - we were selling this technology at £500K a pop. Maybe Gibbo is using advanced techniques but pattern matching and the newer techniques (ie sparse data) dont require you to determine an algorithm - and the use of that word suggests it is regression (or regression type) technology. The new methods work by collecting live data but in this case you would also need to get some SoC data (but not necessarliy accurate - as long as the method is consistent) and capacity data. If you wanted to sell such a model then YES you would have to put so much effort in to make it work for everyone that you would be selling at £1K a pop. I was thinking about a model that works for one person, and then training it with data for another etc etc. Data logging is perhaps the biggest challenge but perhaps linking a Raspberry Pie to a Voltage and Ahr counter could be a cheap option. There would be a lot of other inputs to measure as well (engine revs, temp, solar input to MPPT, output of MPPT etc). It is nice to dream........ this is more a hobby for a bored ditchcrawler......and I am not bored anymore!

Fully agree. I think you would have to be consistent across all methods of data collection.

Yes, of course all data sets would have to have a reasonably accurate SoC values and Capacity numbers as I guess they may be the target outputs. I've not thought it through but for each system modelled you would have to log a SoC - maybe via SG - but it could be done via voltage at rest and linked to voltage under load. The trick is to collect a lot of data so that can then be assessed to reject poor data and to get good averages so you dont have to rely on one off numbers that could be inaccurate. Time consuming but not difficult.

Absolutely, far too expensive, but that's the problem when you try and commercialise something that has to be tuned for individual use. No, I was thinking about a group of guys doing it for free, ie like CanalPlan (which I find wonderful) - collecting data sets and seeing how to predict. I only managed a modelling team, rather than did the nitty gritty of the modelling so wouldnt be capable of the model crunching but defining parameters, data collection and model validation are the time consuming things which is within the scope of many of us. At the end of the day, I am past all of this technical innovation and happy to see my volts high at the end of the day on my NB.

I think it is great to see shots of Loch Ness in sunshine! I am glad you are enjoying your trip. We lived in Scotland for 20+ years and sailed extensively round the coast and up and down the great glen for 3 years. The problem is the weather! You can get some great days - like you are having - but they are few and far between. We spent July and Aug in 2007 anchored in Arisaig waiting for 2 consecutive days of reasonable weather. It never happened. Rain, wind etc. If Scotland had decent weather there would be 30 million people living north of the Great Glen. It doesnt. They dont live there. We really enjoyed loch Ness .....and all the coast including Orkney/Fair Isle/Shetland but have given up fighting the elements in a 40' boat with huge sails, in preference for spending an evening in the beer garden of the Two Boats next to a muddy ditch in Long Itchington (spelling?). Both experiences are (to me) fantastic. The grass isn't always greener. On a canal boat, you dont have to set an anchor alarm .....or worse get up at 2am in the morning when the alarm goes off for no apparent reason. There is also no chance of getting eaten by the Loch Ness monster in Long Itchington. Then again you get the best scenery but it's not that bad down here.

Well maybe, but not sure with the limited information on the link. The problem with models (on which the Datacell will operate) is that it is not easy to have a global "fit all' model. This one seems to 'learn' over time which may make it better but is it good enough? Voltage under load is a function of the voltage at rest and the load. Load is function of the Ahr in/out. SoC is related to Voltage under load, Capacity is related to the voltage change per Ahr out, etc. Each installed system will have its own relationships between these and other variables. There is no reason why you cannot predict SoC and Capacity directly from monitoring voltage and load and/or the rate of change of V and Ahr. For a simple system with say 10 possible loads (lights, pumps etc) and 3 possible chargers (solar, alternator & shore power) it should be possible to come up with a 'pattern matching' type model that can predict a number of performance critera from a set of variable inputs and a set of fixed values The problem comes when you take this model to the next boat when a lot of the fixed values (viz number and size of batteries, wire dimensions etc etc) are changed. If you are using the same model, you really need to create a new training set and determine the new relationships to get the 'perfect' predictions. All the models I ever worked with (and to be honest battery charging seems to be reasonably challenging) needed to be tuned taking them from one place to another to get the best performance. Regression models really only work on data that is within their training sets and predictions suffer when variables and fixed inputs are outside that range - which is quite likely here. I doubt Merlin are using anything more sophisticated or they would be using it in their advertising blurb. The data logging function however looks very interesting and a good model can only be written with a good data set. Are there any modellers in this forum that have looked this?

Thank you, Tony.

Fully agree but I didnt consider my application to be critical to operation. Put it into perpsective. Sailing across Biscay in a Force 6 was critical to life. A quick and dirty approach via trending can give you a reasonable assessment. You also dont need to look at amps back in. Just measure Ahr out. Would you like me to fully define how you do it by trending? No I thought not. By the way, "Just measure Ahr out" should not be taken literally. I should have said, Just measure Ahr out and multiply by 1.25. Oh sorry, I should have said, Just measure Ahr out and multiply by 1.25 to get an estimate of the Ahr you would need to put back in. I dont want to be criticised for writing 'shorthand'.

Er...Yes, I do understand. The bit I have highlighted says that the point that you dont think I understand, I do understand. Of course SoC is not related to voltage, but you dont have to be a rocket scientist to work out how to use voltage at rest to calculate capacity. Wotever obviously understood it. I was trying not to write the ultimate detail so as to bore the guys who arent interested. I measured the voltage at rest when full - ie 12.8 ish, discharged during the day (but not on a known load). Measured voltage at rest again and noted the amps out. You can then do what you want with the numbers - ie work out difference in state of charge between the two values and thus estimate capacity. Would you like me to show you the calculations one needs to do? It seems that you lot want all the gorey details. If your maths isnt up to it, then I can happily oblige. I did this maybe every couple of months but mostly just noted the Ahr used to go from say 12.8 to 12.5 and if the number was the same and not trending down, then I knew the batteries were ok. I cant remember the exact numbers I used. There are two problems with the above approach which I am sure Tony will charge in with. 1) Voltage at rest needs a couple of hours to stabilise the voltage. Not always easy. On our yacht it was more easy to do this with no inverter. With experience you could see the difference between a light load and at rest. That wasnt rocket science either. In a 'single' system, where you do the same things all the time and the number of inputs is low, it is not difficult to understand the difference between light loads and at rest. 2) Normally the accepted way is to put a known load on the batteries to calculate the Ahrs taken out. Great if you need an exact number. I was looking for a trend of decreasing Ahrs out (not in - not needed) with varying voltage at rest so an individual accurate reading was not necessary. Over a period of a year if I saw the 12.8-12.5 range use 80Ahr ( a guess as I cant remember) +/- 10Ahr, then I was happy as long as the trend wasnt downwards. Over 5 years it didnt go down much - again cant remember. I was not after an exact number. For battery charging you dont have to be exact. +/- 10% is good enough. Watch the trends and you dont have to worry too much over individual readings as long as they are near the trend line. Whilst part of my career was spent on materials, ie plastics, paints, sealants etc I spent 10 years managing computer modeling teams, modelling a range of refinery/chemical plant applications. The models here were to predict operation of processes - viz monitor inputs and outputs and hence predict performance. Modelling a battery is no different. I made a comment in a post above about Smartguage (which I didnt elaborate on - yet it got some very negative vibes- so here is more detail). It would not be difficult at all to write a model based only on voltage that would predict a part of the charging process - After 5 years of watching batteries and charging/discharging, I could have written something similar for my set up given my knowledge of computer modelling, going from techniques such as the simple regression models up to more challenging methods of Topology or sparse data/others. I have read all the comments on here about Smartguages which is why I have not done any modelling myself and rely far more heavily on the Amps in/Amps out but following voltage does give you a lot of information if you use it in comparison with the other inputs. What would be interesting is to take a model based on voltage only (something similar to Smartguage) and add in the extra inputs of Ahrs change, plus inputs from the alternator (and or controller) plus solar, type/size of battery. Maybe the Ahr counters do some of this but I dont think they go far enough as they have their own model built in. Each system is diferent so you have different inputs/outputs. It would be possible to write a model for your own system and then this may be transferrable to other systems where a knowledgeable user could input his own data. Has anyone here done this? Apologies for such a long post but I am getting tired of a number of you trying to tell me I am thick.

Ah, very useful. So for a 100-50% cycle, these Trojans will do 1500 and for 100-80% they will do almost 3 times more. I will do a bit of searching on wet lead acids. This is why I was always told to not drop below 80% when we first started sailing.

I was actually asking the question as I am intrested in understanding the answer? I know 100% down to 50% will knacker a battery (but after 300 cycles or less?) and 100% down to 80-90% is pretty frugal (???) but then long life. What is the effect of 100 to 60%, 100 to 70% etc? You guys seem to profess to be the experts? All I know is how to keep bog standard wet lead acids in good shape and dont profess to know more. I do see the adverts saying 600 cycles, 1200 cycles and upwards.

What is a cycle? Is it is 100% down to 50% and back up again? It is certainly not 100% down to 80-90% and up to 100% again as over a 5 year period we must have done 1500 cycles. To me, looking after your batteries is to try and not fall below 80% which means having a big battery bank. On the yacht we could only afford 400 Ahrs (to keep weight down). On our NB we have 700Ahrs. If you run from 100% down to 50% and back all the time, then you will knacker them. Surely that is common sense? On the yacht our batteries lasted 5 years because of the SoC I kept them in, not because of reduced capacity.

There seems to be a theme from a number of you here that I dont know what I am talking about - and that my SoC was much lower than I was thinking (particularly Wotever)....ie I was keeping it between 80-100%. Also Mike referred to total capacity in one of his posts. I did monitor voltage at rest as I have said on a couple of posts. If you have 12.8V (almost) and it doesnt go below 12.5V then things are fine. I managed the system to keep it at these levels most of the time although the accuracy of the voltage measurement I have no idea of. Rest means a couple of hours with no load - I did test this now and again. Each morning you could see the voltage under load and see that everything was normal. I probably had enough information after the 5 years to build a model (like Smartguage) for what that is worth. In terms of capacity I did check from time to time the amps in/out versus voltage at rest and was happy that I wasnt loosing capacity big time. Ref your other post, spending £350 on solar will be very advantageous for the summer (and certainly better than an AtoB - if you have space) but very little advantage in the winter.....and winter is when you need the power as your existing solar will not be working nearly as well. I am very surprised you made that recommendation.

Mike, I didnt mean to insult you and apologise if that is the way it came over. Your experience is real and shows that it doesnt always go by the book. There is more to it than the chemistry that has been documented here. In our case we hadnt lost 50% of our capacity in years 2,3 etc as the voltage at rest showed more capacity than that but cant remember the exact number. We started with 440Ahr so a 50% decrease would have had a significant effect on days when we used 80 Ahrs.

Tony, I usually read your stuff with reverence both here and in the magazine.........however, I very much doubt the two sentances you quoted. Dont be so presumtive. My batteries lasted 5 years+ with no problems whatsoever - and it was not frugal use - you (a general you) cannot and we cannot do frugal use living aboard. The cabling was all fine. If I was mislead and the SoC was 80% not 100% when charged then the batteries would have died long ago. If my batttery and charging knowledge was suspect then again they would have died long ago. The only potential weakness was the brand new Volvo alternator which was only 70A but was matched OK to the size of the battery bank. Finally I do take offence in the comment posted above. That sentance suggests that I had a problem with my charging/batteries. I did not. They lasted 5 years plus on a brand new boat and performance was better with the Sterling unit. If there was a system defect with the original layout - ie the alternator, then the problem was certianly cured with the AtoB. Hence the AtoB was certainly worth buying. Interesting that ALL those throwing bricks at the Sterling unit HAVE NEVER USED ONE (and maybe never even seen one). Looking after batteries is not Rocket science but you seem to be making that way. A bit of common sense and it is easy with the right tools.

I am quite astounded by the vitriol poured out here about Sterling products. Whilst the canal world seems dominated by Victron, the sailing community see Sterling as premium products. Funny that a 5 year battery life span seems normal in sailing yachts whereas less than a year seems possible for canals - how can you destroy your batteries in 5 months? Certainly this is NOT down to different suppliers but maybe you have something to learn from the 'other side'. Someone seemed to be saying I was a gullable fool for having the AtoB. Do your bog standard cheap batteries last 5 years+? I am out of here.

Not quite right but not far off. Yes typically the motor would be run first thing to get us out of a marina or off an anchorage, but the solar was a panel that had to be taken off when sailing so maybe only used every other day. Wind/water gen, used only when sailing fast enough. I will be guided by what you say on our SoC but if it was only typically 80% then there is no way the bank would have lasted 5 years. I was paranoic about keeping it above 'My' 80% and it went below only on a few occasions, once on a North Sea race from Aberdeen to Stavanger where we couldnt run the engine and likely we went to 50% SoC (by amps out and voltage at rest) and another couple of 2 day races when it went below 'my' 80%. On a sailing yacht with no inverter it was pretty easy to see the voltage at rest as a lot of the time when racing everything was turned off.

1) Agreed 2) Agreed. I used 500% as that is what Sterling say..... 3) It is interesting that most of my friends with Sailing Boats who were also live aboards (so Yachts from 35-45 ft) were not changing batteries that often. 4-5 years seemed the norm. Our set up was pretty typical with 400Ahrs and only a very small inverter - fridge was 12V and electrical appliances (hair driers, curling tongues, coffee machines etc) only used on shore power. The main drain on power were the chart plotter (circa 4Ahr), fridge (3-4Ahr when on - I think), anchor light and tricolour at the top of the mast plus the only big draw was the anchor windlass which drew 80Ahr if I remember correctly. Some boats had a Girlie Button which also took big power. Only the biggest, heaviest boats had a washing machine!!!!! On this forum it seems the norm that batteries last a very short time. Could it be that it is the use of big inverters (2KW and above) that is killing the batteries? It will be interesting to see how mine last as our One Pot and Coffee maker are both taking 1.2KW and Washing machine that keeps tripping when the wife does a 30deg wash - told her to do cold washes for now.

I am going to disagree. In an earlier post, you said my first statement was wrong in that the AtoB fools the alternator into charging at a faster rate. The Sterling charger reduces the voltage from the alternator - not increases thus fools it - and not increases voltage as you say. It is not the same as other Ato B units. It is a fact that we got more amps into our batteries with the Sterling unit. Probably 25% of the boats we knew had these units and the owners saw the benefit. No one in the NB world seems to use Sterling which is surprising considering the number of sailing boats that use them. I doubt Sterling would be in existence if your coments above are true as they would have been hammered by Trading Standards. Sterling do not quote at what stage of charge their Ato B units are 500% more efficient but for us we saw a big efficiency change at the higher end of charging. Rather than continually saying the chemistry doesnt allow faster charging, why not consider the facts that people who actually use this kit see a benefit. If I had another yacht I would certainly add a Sterling AtoB. I am holding off doing so on my NB as I run the engine far more and it seems to charge far better at tickover than the Volvo unit I had.

Right let's rewind. After a night at anchor we had used 40 A. 30 mins to an hour of engine with An AtoB brought that up to a state of charge a lot faster than no AtoB. Battery bank 440amp. Maybe the state of charge was not 100%. Let's assume it was only 95%. Maybe it was even less. Maybe I should be saying how long it took to put 40A ( as per the meter- which may only be 35 A true) back in. The AtoB was faster. Voltage at rest was fine. The batteries lasts 5 years and more. I am looking at a comparison here. Have you tried an AtoB? I lived with one for 4.5 years.