grendel

1 you can do either, but tescos is just up the road 5 minute walk or about the same by car. 2 you can get the car to the back of the boat for unloading, parking isnt too far 3.i have never heard of problems with cars 4, fuel use depends on how far you travel, and whether you go with the tide or against it, it can be different for every trip. 5. plenty of places to do both

yes that would do the job, but why make things any more complex than necessary, if I can get the power out of 11.1v lithium without needing to change out the speed controller etc, then that is the way to go I think, if I go for a 10Ah battery that will give nigh on 2 hours runtime at the 5A maximum in water consumption (the 20A is under stall conditions, and I havent managed to stall it out even with weed on the prop.)

yes i noticed, looks like the same spot

my thoughts are to fix the impellor / overheating problem, and treat the engine warming from the calorifer as a bonus, if you leave the immersion on frost guard setting, it should stop the engine freezing too.

It certainly sounds like you found the spot, its lovely there.

basically in the test the lithium settled out at 11.7 Volts under load, while the Lead acid settled to 12.05V under load.

here are the discharge curves, of the two types of battery, the lithium curve would be dropped to start slightly below the lead acid, but you can see that after the first few minutes the lithium would be higher output than the lead acid, and stay that way longer. ignore the voltages, I m just using the graph because it shows the discharge curves.

basically the results showed that the lead acid battery gave out 60W (5Amps) initially on a full charge, the better lithium battery managed 58W on full charge voltage. However, the lead acid battery will slowly lose voltage at that current drain, while the lithium should hold pretty stable at that level throughout. This is just using a bulk standard lithium tool battery, the ones they have for model boats are capable of delivering much higher currents, i have yet to test one of those (as i dont have one yet - they are on my boot fair watch list for testing purposes) the other test i did was using a smaller lead acid battery as ballast, and one at about half the weight of the big ones i use is the perfect ballast, bringing the boot topping just above water level. You will also see just how much water this single 35mm prop moves by the wash up the back of the test tank. i would worry about cavitation if i upped the power much more than it is at the moment. the lithium batteries will come in at about 1/2 to 2/3 of the required ballast weight.

Video 1 with the first (none too good capacity wise) lithium battery. Video 2 is with a 12V (11.1V ) lithium tool battery of 2Ah capacity, this gives a lot better performance than the original lithium battery which i could see discharging as i watched it.

mostly due to the potential 20A stall current, not many dc to dc converters can handle those types of current (well not ones that wont be bigger and heavier than the battery in there, ditto resistors, you wouldnt want to put a bit of heatshrink tubing on a potential voltage dropping resistor we used to do similar with 50W 1 Ohm resistors to fast charge ni cads for model car racing, even bolted to a good heat sink, these got hot enough to brand fingertips if you forgot and touched one, anyhow testing has been done in the upstairs white enamel test pond, and though the 11.1V lithiums are not quite as good as the 12V lead acid they still give pretty impressive performance, i did have to find a better 11.1V lithium pack and cobble together the connection.

this means that if i accept a very slight drop in power i can change over to a lithium battery quite simply, the other option is to increase to 14.8V, where i will need to change the speed controller too, and gain an increase in power slightly. lets see what the in water tests show.

a power usage monitor has been purchased, amazing how cheap these sort of things are nowadays, and tonight after creating some wiring to insert it into the motor circuitry some tests were run, with the standard lead acid battery at 12.7 nominal volts, the motor consumption running free is 18W, using a lithium pack at 11.1 volts nominal it drops to 17.5W, next job tomorrow is to repeat the test in water, i want to see how each of the batteries reacts to the added load, theoretically the lithium cells should hold up longer as they are capable of delivering a much higher current than the 12v lead acid battery.

Perhaps more of an indication of the content that is contained within, false advertising and all that, if they refer to it as a show they can deny any non factual content.

i have seen different opinions on whether it does or not, but i think boating was originally excluded, but then maybe that was then changed, but it certainly doesnt apply to day boats.

Well, at least the ones i have made shouldnt break that easy, and if they do, its easy enough to make more.

I think of it more as restoring original function in a fashion sympathetic to the original, and if that means making parts to match the original, then so be it.

Have fun, unfortunately I haven't had a chance to fit these to the cupboards in the cockpit area yet, to replace the brass screws currently in use.

apparently according to my google search the tide always flows with the waveney, so whatever is happening on the waveney, is what the new cut is doing.

I believe its down to how fast the two rivers can empty into Breydon, if the yare is emptying or filling faster than the waveney, then i would imagine the new cut would flow one way or the other to compensate, but not necessarily in a predictable manner, it would be interesting to find if anyone has actually measured the flow and created a graph showing how it reacts in comparison to the tide times.

I bought an OL40, and with it you can use the os maps app and download an offline copy of the map to use on a tablet, i use this with a gps function to show me where i am, even if i dont have an internet connection.

we do have the technical questions and answers section, which sort of covers this type of topic (I can move this into there if required)

probably this page https://www.norwichcamping.co.uk/shop/category/camping-water-and-waste-toilet-fluid-55/

https://www.norwichcamping.co.uk/

after trial runs at the wooden boat show, it was apparent that the model was stern heavy, this means some modifications to the battery are in order, the current lead acid battery weighs in at about 2.7Kg, I can drop the weight to at least 1/3 of that by going to lithium polymer batteries, the main issues revolve around voltage, I need to perform some speed tests to see if an 11.1v lithium battery can produce the same performance as a lead acid battery, or whether I will need to go up to 14.8V.

that will depend on how often Robin fills up his 1000 litre tanks