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Post by quaysider on Mar 9, 2017 21:30:39 GMT
On Ellis we've got the 75L twin coil surecal cauliflower with a 1kw 230v immersion heater fitted... Given that we don't have shore-line and my little old honda generator can't quite run it, it is only being used with the engine running to speed up the getting of hot water or encourage the radiators to get hot faster... (well the latter bit not so much now the fire is fitted) Each afternoon this week when I've called in to the boat on the way home from work the batteries have been at 100% - and presumably have been for a while given there is only the 12v fridge/freezer running.... which has left me thinking, the solar panels are just short of 600w and the mppt has a 20a "output" on it - perhaps/presumably a dump? which could possiblybe utilised to power say a 250w 12v immersion heater... My question is, how practical/difficult would it be to fit one of say these link in to the top of the tank without fecking it up? I wonder if there is such a thing as an adaptor to replace the existing "mains one" with the (smaller?) 12v one? Has anyone done this before or am I trying to solve a problem that doesn't exist? - ie, I could always put the immersion on via the inverter for say half an hour when I get home to get enough water for a shower and trust the panels to shove more power back in for the last few hours of sun each day - given the batteries will now allow a greater charge again after the hammering. |
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Post by Deleted on Mar 9, 2017 21:51:31 GMT
Your biggest issue will be reducing the thread size if your cauliflower has a 2 1/4" bsp thread.
Low voltage stuff is 1" - 2" bsp. Reducing bushes are not common for 2 1/4" bsp
Any chance of running an inverter for the immersion when there is excess solar capacity to top the batteries up?
Sorry, I see you had thought if that! Give it a whirl and see how it goes?
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Post by quaysider on Mar 9, 2017 21:53:35 GMT
i dont think that would work - the output on the controller is a max of 20a and the 1kw 230v would need about 85a wouldnt it?
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Post by Deleted on Mar 9, 2017 22:00:10 GMT
i dont think that would work - the output on the controller is a max of 20a and the 1kw 230v would need about 85a wouldnt it? I meant via the charger not as a power supply. As you say, it will spank the batteries. That, or get another Genny. We upgraded to a secondhand eu20 from our nasty Clarke 1000g Genny that couldn't run.the immersion. www.petepower.co.uk/ decent guy to deal with.. |
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Post by Telemachus on Mar 9, 2017 23:03:27 GMT
Why not fit a timeswitch to run the 230v immersion during the middle of the day, then the solar can replenish the batteries in the afternoon?
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Post by quaysider on Mar 10, 2017 6:41:55 GMT
Why not fit a timeswitch to run the 230v immersion during the middle of the day, then the solar can replenish the batteries in the afternoon? I'd thought about that - although that would mean leaving the inverter on... which I'm not keen on as even on power save mode, it sucks a fair bit of power.... ANOTHER reason I should have tried saving up an extra 700 quid and getting a posh one rather than the photonic universe offering I suppose :-( Then again - I suppose if the sun is out, the panels should more than keep up with it.... I could suck it and see (and yes, that wouldn't be a first for me before anyone passes comment :-) |
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Post by Deleted on Mar 10, 2017 7:56:09 GMT
Use a timer to switch the inverter on and off?
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Post by Deleted on Mar 10, 2017 8:06:36 GMT
It would be a bit technical but you could use a miniature solar panel (say 2x4 inch) to switch a relay which would be able to turn on the immersion heater when it is sunny enough to have excess power from the solar. I did this when I made a solar tracker. The mini panel directly switched a relay when the sun was out then off again when sun went behind clouds or in the case of the tracker when the actuator had rotated the main panel to line up with the sun thus shading the mini panel which was at right angles to and to the right edge of the main panel. But I don't think using an inverter to heat your water is appropriate anyway. Most practical setup I've come across is the good old Morco. Unlimited (subject to gas and water availability) hot water when you want it  and no electric. Abd no tank to run out and go cold. |
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Post by JohnV on Mar 10, 2017 8:38:50 GMT
Oddly enough this is a problem I have been mulling over for a while. especially as I have been looking at my solar control monitor and it's showing 100% charge and the "dump load available" sign on. Researching links on t'internet for low voltage immersions, I found one site where they had put a tee piece in the cold water feed input of the cauliflower (to replace an elbow) using the other side of the tee to fit the 12v immersion, so that the majority of the heater was poking through into the tank. I thought that was a good idea ....... until I looked at my tank and found that my cold water inlet was 15mm instead of the 22mm they had used  The other solution I had been wondering about (same as you) was driving the immersion with an inverter but using a relay driven by the dump load signal from the controller to switch the inverter on/off (depending on battery voltage). I have a cheapo modified sine wave 1.5Kw unit that is used exclusively for the kettle and I have been thinking of putting this to work for this as well (obviously some form of protective switching so that both loads can't be on at the same time) At the moment however this (for me ) is still a theoretical exercise |
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Post by quaysider on Mar 10, 2017 10:06:38 GMT
Oddly enough this is a problem I have been mulling over for a while. especially as I have been looking at my solar control monitor and it's showing 100% charge and the "dump load available" sign on. Researching links on t'internet for low voltage immersions, I found one site where they had put a tee piece in the cold water feed input of the cauliflower (to replace an elbow) using the other side of the tee to fit the 12v immersion, so that the majority of the heater was poking through into the tank. I thought that was a good idea ....... until I looked at my tank and found that my cold water inlet was 15mm instead of the 22mm they had used The other solution I had been wondering about (same as you) was driving the immersion with an inverter but using a relay driven by the dump load signal from the controller to switch the inverter on/off (depending on battery voltage). I have a cheapo modified sine wave 1.5Kw unit that is used exclusively for the kettle and I have been thinking of putting this to work for this as well (obviously some form of protective switching so that both loads can't be on at the same time) At the moment however this (for me ) is still a theoretical exercise I was all excited then thinking that would be a good idea... but alas, I'm sure mine will be the same. I did wonder about connecting in another little tank "somewhere" say 20-30 litres ...not necessarily a true (expensive) calorifier as such but something I could "fit" the little 12v heater in to. I do hope someone HAS already done it sucessfully though as it seems such a waste of energy - as it stands, I boil the electric kettle a couple of times a night whilst working just to use some up ! |
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Post by smileypete on Mar 10, 2017 10:17:34 GMT
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Post by Telemachus on Mar 10, 2017 10:21:27 GMT
Why not fit a timeswitch to run the 230v immersion during the middle of the day, then the solar can replenish the batteries in the afternoon? I'd thought about that - although that would mean leaving the inverter on... which I'm not keen on as even on power save mode, it sucks a fair bit of power.... ANOTHER reason I should have tried saving up an extra 700 quid and getting a posh one rather than the photonic universe offering I suppose :-( Then again - I suppose if the sun is out, the panels should more than keep up with it.... I could suck it and see (and yes, that wouldn't be a first for me before anyone passes comment :-) Do you know what the actual static consumption of the inverter is? I bought a cheapo PSW 1500w inverter for my caravan and I think it only uses a bit more than an amp. More than offset with a decent solar system. I just have a 100w panel and when I accidentally left the inverter on whilst away for a week, when I got back the batteries were still reasonably well charged, and it wasn't at the height of the solar season. |
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Post by smileypete on Mar 10, 2017 10:33:45 GMT
I'd thought about that - although that would mean leaving the inverter on... which I'm not keen on as even on power save mode, it sucks a fair bit of power.... ANOTHER reason I should have tried saving up an extra 700 quid and getting a posh one rather than the photonic universe offering I suppose :-( Then again - I suppose if the sun is out, the panels should more than keep up with it.... I could suck it and see (and yes, that wouldn't be a first for me before anyone passes comment :-) Do you know what the actual static consumption of the inverter is? I bought a cheapo PSW 1500w inverter for my caravan and I think it only uses a bit more than an amp. More than offset with a decent solar system. I just have a 100w panel and when I accidentally left the inverter on whilst away for a week, when I got back the batteries were still reasonably well charged, and it wasn't at the height of the solar season. Gonna be horrendous as it's a low frequency inverter, it should have a power save mode which'll knock it back to a more sane level. Guess quaysider wants to heat the immersion from surplus solar without wear and tear on the batts. |
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Post by smileypete on Mar 10, 2017 10:45:26 GMT
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Post by Deleted on Mar 10, 2017 10:49:31 GMT
I did wonder about connecting in another little tank "somewhere" say 20-30 litres ...not necessarily a true (expensive) calorifier as such but something I could "fit" the little 12v heater in to.[br ! What about a beer barrel with hot water cylinder lagging on it? Aluminium so easy to cut and adapt. |
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and no electric. Abd no tank to run out and go cold. 
