Grifter

What size? Where are you based? Joe

£125 for 250W is very cheap! Could you post a link to the supplier? Cheers, Joe

Haha Stuart, good photo. Perhaps I should have got one with a generator on top. Good use of space! The JA013 looks quite small in the photo. Hope it's big enough. Anyway, I won an ebay auction for £142 + delivery tonight, so I won't have to wait too long to find out.

Good point, suppose there's no way of telling. Replacement grates and glass are available from various outlets at the moment though. And I could replace the whole stove two or three times before I get to the price of some branded stoves. Think I'll keep trying to win auctions at low prices.

I approached an ebay seller and asked for a cash-on-collection price and he said £150. ebay auctions sometimes go for around £150. Some websites are selling for £175.

Excellent. Sounding good so far! Picture of the stove...

I've been looking for a new stove and have come across a 4kW stove available at very reasonable prices. Branded as Vortigern V013 or Sunrain JA013s or "Petit Furzebrook" or "Riddler" or "Rutland" or sometimes not branded at all. All are CE marked though and have a efficiency of 75-80% stamped on. I was wondering if anyone has any experience of them. They are available for as little as £150 if you shop around.

I don't know what they're made from. It's not rubber but it's quite flexible with a bit of give to it. Joe

I have this down in the bow and have bought some more to put on the roof. It's designed to allow drainage, is easy to cut, and feels softer and warmer than steel. Much cheaper than the competition too. I think the company may have stopped making it though, so you'll have to be quick! Link to Amazon Regards, Joe

Yeah, 53kWh is the amount generated over the ten months or so. Not very much at electricity company prices, but priceless when it is exactly where it is needed. Yes, how do you want me to send it? I can send you the Matlab code I use if you want it as well. They are free standing and I've only had that one incident, and that was freak wind and I was on the river. I spend a lot of time on the canal where it's much less windy. I tried for a bit with the switchable magnets that you get on a DTI but they rusted and made my roof look a mess. I only have them at a slight angle so the rain runs off now. The only thing is that they are more liable to theft, I suppose. I don't know whether series or parallel is best, perhaps you can tell me by looking at the specs. 100W panel HJ solar HJM100M-12 Voltage at Pmax 18.98V Current at Pmax 5.27A Open circuit voltage 23.1V Short circuit current 5.69A 120W panel (not as big as I thought!) MBF120 Voltage at Pmax 17.5V Current at Pmax 6.86A Open circuit voltage 21.5V Short circuit current 7.55A It's a 12V system. Regards, Joe

Here are some plots of the data I recorded from my solar system from when I installed it on 2011-09-27 to when the boat came out for a repaint on 2012-08-01. I thought it would useful for people to see what power you might actually get from a system in the real world. My solar panels (100W and 130W wired in series to a MPPT controller) Daily energy output The mean average of 172 Wh per day is 14.3 Ah per day. 53 kWh would cost about a tenner from an electricity company! While there are a lot of high peaks in summer, the average daily energy output is not all that high (explained by the next graph). On one windy day in April, the panels blew off the roof, meaning there was very little power generated that day and one panel's glass shattered. After that day, power output will be reduced from that panel. The 50-day average line slopes off because it is including the zeros either side of the recorded data. Seasonal averages The batteries often reach full charge as the day goes on meaning that power output tails off, rather than having a normal distribution about noon. In summer, when more days are spent cruising, average power output falls significantly during regular cruising hours. The MPPT controller does not charge the batteries when the engine is running because the alternator's charge voltage is higher than that of the controller. I am missing a month of data for summer because I took the panels off when I took the boat out of the water. Average power output (7W) is average for a 24-hour day. Hope that is interesting for someone. I've been very impressed with solar power. It generally means I have enough power to live (part-time live-aboard) without having to use the engine while stationary. I'm hoping to replace them with larger panels at some point, especially the broken one. Regards, Joe

I tried with puppy pads without much success. It seems many people do succeed, but I think it trains them to think that going inside it OK. With my little dog, the best thing we did was to get him a cage. Take him straight outside whenever he's been asleep in the cage and wait for him to wee, and give him plenty of praise when he does. I was skeptical about cages at first but he loves it now. It has a big fluffy sheepskin in the bottom and a cover over the top. Goes in of his own accord when he's tired. Very useful when your going out, or going through locks and you want to keep him safe.

I've just moored up there, just after Trent bridge. There's loads of boats there all ready. Should be a good weekend. Joe

You can buy my old one, if you want. Juta MPPT 10A 12V. It's on ebay at the moment. No input for the wind turbine though. Joe

Looks like a clever bit of kit! How much was it?

I don't think so. Quite the opposite perhaps. The voltage is measured internally by the regulator before the charging leads so putting a diode in the lead would reduce the voltage at the batteries. I don't know enough about electronics to start taking the innards of the regulator to pieces.

Haha. This regulator and This monitor. Power draw of monitor at ~10V is 15mA and <1mA on standby (according to IVT's literature). Negligible, I think. It records data to an SD card, which I then copy to a laptop.

These are a few of the plots I made from my data. Average power produced in a day Amount of energy produced in a day On the 21st of August I had my engine running for quite a while, which is the reason for the low amount that day. None of the data I have proves what is happening as the batteries approach 100% SOC though. All I know is that if I leave the boat with no power draws for a day or two, when I return, the batteries will be at 100% SOC. When I get my monitor back, I'll see what I can find out. Joe

My program was more for looking at days, weeks and months of data to get daily averages and totals etc, but I plotted the data anyway. If you have lots of data, I'd be interested to see. I only have a couple of weeks. Your data shows that the battery is being taken as high as 14.1 and 14.2 volts. Power into and out of the regulator. From this data, your regulator is, on average, 94% efficient. PDF link A graph of panel and battery voltages PDF link A graph of panel and battery currents PDF link

The data I recorded from the solar controller remote shows that the batteries are taken as high as 14.1 but the charging regime is not as clear cut as the literature would have one believe. Unfortunately, I've had to send back my remote for replacement, else I would have done a little experiment to see if it is doing what it is meant to. There is also some discrepancy between the voltages that the regulator remote shows and the voltage the SmartGauge shows, although this could be to do with voltage drop or calibration errors, etc. I'll have a proper look through my data to see if there's anything interesting tomorrow. Joe

I must have exactly the same set up as Trev. This is an interesting topic. My understanding of the literature disagrees slightly with the info you got in your email from IVT. Here's what I believe is going on: In the "main charging phase", the battery is charged with maximum current until it reaches 14.1V, then the battery is then held at 14.1V for several minutes in a "timer phase". After that, the controller enters a "charge maintenance phase" and applies pulses to the battery whilst holding it at 13.7V. The confusing thing for the observer is that the green "battery full" LED on the regulator comes on once the battery voltage has reached 13.5V in the main charging phase. So if your batteries are getting taken to 14.1V before the controller drops the voltage, they should be getting closer to 100% SOC on the SmartGauge. I agree that it would be nice if the voltages were adjustable but it's probably not as much of a problem as it first seems. It would be even better for the controller to drop the voltage at 100% SOC but I'm guessing the reason they don't do this is the reason why a SmartGauge costs more than a voltmeter. I've written a program to help me plot useful information from the data the monitor records. If you want to send it over, I'll run your data through it, to see how it looks. Joe

Thanks for the replies. Those that voted for something else - anything you have in mind? I think I might go with the Steca. I'm not that convinced by the Juta controller as it rarely, if ever, gets the batteries to 100% on the smartguage. 90% seems to come up fairly quick but doesn't get much higher - maybe because the cut-out voltage is 14V while the Steca has a 14.9v equalisation charge. Does that sound right? Joe

Hi there. I've come across some 100W solar panels for £180 each, which I thought was too good to miss. My current set up is a 120W panel wired to a 12V battery bank through a 10A Juta MPPT controller. I'm wondering what is the best way to connect the extra panel... 1. Get another Juta 10A MPPT to create two basically separate systems both connected to the same battery bank. Can two controllers be used like this without interfering with each others operation. (Cost = £77) 2. Get a Juta 20A MPPT and wire the panels in parallel. (Max solar panel voltage for the Juta MPPTs is 23V - spec sheet for both here Midsummer Energy link) (Cost = £133) 3. Use a different controller that can cope with the panels in series, perhaps Steca Solarix MPPT 20Amp from Solar Express UK(Cost = 180) 4. Something else all together. There is the possibility I might add more panels at a later date. I'd be interested to hear your opinions. (Edited to add costs) Cheers. Joe