PCSB Posted June 16, 2022 Report Share Posted June 16, 2022 I'm currently researching ways to use solar to heat the water on our boat. Currently have 550W solar, and a Victron MPPT controller 150 | 35 and a Victron Multiplus Inverter/Charger. The calorifier has a 1KW immersion heater in it which is only powered when on hook up. On days like today the solar has topped the batts up by mid morning and runs everything on the boat (other than the washing machine). I can even use the coffe machine and it copes fine. I'd like to be able to heat the water by using the excess solar, saves running the engine or hooking up when in the marina. I accept that some days it won't get me anything but on others it will or could. I do not want to mess about with arduino's and other "creative" ways of making the kit do what I want, ideally a plug and play solution is rquired. But I accept there may be some woring changes needed. I've found some domestic solar diverters on the web, such as SolarImersion, Solar i-Boost and Myenergi Eddi. Has anyone used one of these and did it/does it work? TIA Paul. Link to comment Share on other sites More sharing options...
Quattrodave Posted June 16, 2022 Report Share Posted June 16, 2022 If you fit a dual voltage (12v & 240v) immersion element could you use the 12v immersion as an MPPT dump load? Link to comment Share on other sites More sharing options...
jpcdriver Posted June 16, 2022 Report Share Posted June 16, 2022 31 minutes ago, Quattrodave said: If you fit a dual voltage (12v & 240v) immersion element could you use the 12v immersion as an MPPT dump load? I don't think the OP will be able to do that as the Victron MPPT 150 | 35 does not have connections for a dump load. Link to comment Share on other sites More sharing options...
MtB Posted June 16, 2022 Report Share Posted June 16, 2022 6 hours ago, PCSB said: I do not want to mess about with arduino's and other "creative" ways of making the kit do what I want, ideally a plug and play solution is rquired. "I want, I want..." If/when you find it, somehow I doubt you'll share it with the forum. Link to comment Share on other sites More sharing options...
Tractor Posted June 17, 2022 Report Share Posted June 17, 2022 Try this https://youtu.be/N4QH7m0LXos Link to comment Share on other sites More sharing options...
PCSB Posted June 17, 2022 Author Report Share Posted June 17, 2022 10 hours ago, MtB said: "I want, I want..." If/when you find it, somehow I doubt you'll share it with the forum. If I do find it I will share it with the forum. 2 hours ago, Tractor said: Try this https://youtu.be/N4QH7m0LXos Thanks I have seen this but not sure I want the faff tbh. Link to comment Share on other sites More sharing options...
magnetman Posted June 17, 2022 Report Share Posted June 17, 2022 (edited) These little devices look interesting. Programmable overcurrent relay with hall effect non invasive ammeter https://www.ebay.co.uk/itm/184692219522 You could set it to route power to an alarm at say 25 amps then wire the alarm output through relays to switch on immersion heater. Not sure it would work but might be interesting to play with. Its not a dump for when batteries are full but -maybe- could be used to send power to the immersion heater when there is enough of that power. ETA just noticed in the spec it will switch 6A@230vac Item Type: DC Digital Ammeter Material: Plastic Model: SZD07 Input Voltage: DC8-35V Measurement Type: DC current Range: 0.3-50A Sensor: Hall sensor Sensor Input Current: 25A Sensor Output Voltage: 2.5±0.625V Sampling Frequency: 2 times/s Alarm Output: Upper and lower limit alarms are output from the same relay Contact Capacity: 6A/250VAC, 6A/30VBC, resistive load Working Environment: Temperature -10~50℃, temperature <85%RH non-corrosive places Accuracy Level: 0.5 level Edited June 17, 2022 by magnetman 1 Link to comment Share on other sites More sharing options...
robtheplod Posted June 17, 2022 Report Share Posted June 17, 2022 If only Victron and other makes made a dump load option that would make it so much easier to do........ 1 Link to comment Share on other sites More sharing options...
magnetman Posted June 17, 2022 Report Share Posted June 17, 2022 The.smaller victron MPPT do have a load bus on them which is programmable but not the big ones. Link to comment Share on other sites More sharing options...
robtheplod Posted June 17, 2022 Report Share Posted June 17, 2022 30 minutes ago, robtheplod said: If only Victron and other makes made a dump load option that would make it so much easier to do........ I've just emailed Victron as a suggestion.... it would be a killer selling point - a programmable output on their MPPT's where you could switch on/off and set at what state your batteries should be at before it supplies power to the immersion. Link to comment Share on other sites More sharing options...
magnetman Posted June 17, 2022 Report Share Posted June 17, 2022 (edited) My MPPT 100/20 units have exactly that function. The 100/30 and the 100/50 don't have it. Nor does the 150/35. Perhaps a useful argument for having individual controllers for each PV module. Edited June 17, 2022 by magnetman Link to comment Share on other sites More sharing options...
jpcdriver Posted June 17, 2022 Report Share Posted June 17, 2022 31 minutes ago, magnetman said: Perhaps a useful argument for having individual controllers for each PV module. Or maybe not, I've not got enough space in the cupboard for 10 MPPTs! 😁 Seriously though, it is a shame Victron don't put the load dump facility on the larger MPPTs. Currently my solar array is pumping around 1kw into the batteries. At the moment I need everything I can get into the batteries but if I don't cruise for a few days it would be good automatically divert excess to do something useful. Link to comment Share on other sites More sharing options...
magnetman Posted June 17, 2022 Report Share Posted June 17, 2022 (edited) Is that a 12v system? If you are a heavy consumer it's worth putting in a 48v setup to keep the amps and number of controllers down. The victron 100/20 is available with 48v option. ETA when I mentioned one controller per module obviously this would be two modules as they are 36v nominal and the controller does 100V input. Also thinking of big modules 400w or more. Edited June 17, 2022 by magnetman Link to comment Share on other sites More sharing options...
jpcdriver Posted June 17, 2022 Report Share Posted June 17, 2022 19 minutes ago, magnetman said: Is that a 12v system? No 48v for a hybrid propulsion system. Hence why I gave a power figure going to the batteries rather than saying over 20A. Your suggestion was fine for certain circumstances, so just having a bit of a grin really and pondering why Victron don't put the dump load facility in the bigger MPPT units. The boat builder has used a 150/45 unit in my boat which is fine for the 10 x 175w panels I have (2 strings of 5 paralleled). Appears to be working well and yielding above my expectations (based on the Victron modeller). So overall I'm happy. Also a shame for the OP's situation as his MPPT also rules out a super easy fix. Link to comment Share on other sites More sharing options...
redwing Posted June 17, 2022 Report Share Posted June 17, 2022 I know it's sacrilege, but some lithium users plug the immersion into inverter and go play. I plug my immersion via a timer into a socket for 1/2 an hour a few times/day 1 Link to comment Share on other sites More sharing options...
magnetman Posted June 17, 2022 Report Share Posted June 17, 2022 5 minutes ago, jpcdriver said: No 48v for a hybrid propulsion system. Hence why I gave a power figure going to the batteries rather than saying over 20A. Your suggestion was fine for certain circumstances, so just having a bit of a grin really and pondering why Victron don't put the dump load facility in the bigger MPPT units. The boat builder has used a 150/45 unit in my boat which is fine for the 10 x 175w panels I have (2 strings of 5 paralleled). Appears to be working well and yielding above my expectations (based on the Victron modeller). So overall I'm happy. Also a shame for the OP's situation as his MPPT also rules out a super easy fix. I think there is a load option on the larger MPPT units if you buy more hardware. Maybe Victron took the view that people spending good money on larger controllers are likely to be happy to spend more on a fully networked system. It is called Victron VRM or something. A bit cynical but it could just be a profit-driven choice to not have the load bus on the larger controllers. Or heat management issues? Link to comment Share on other sites More sharing options...
jpcdriver Posted June 17, 2022 Report Share Posted June 17, 2022 4 minutes ago, magnetman said: A bit cynical but it could just be a profit-driven choice to not have the load bus on the larger controllers. Or heat management issues Yep, I could go with either or possibly even both of those. Link to comment Share on other sites More sharing options...
Tony Brooks Posted June 17, 2022 Report Share Posted June 17, 2022 Don't some battery management systems have programmable outputs for a relay, such as used by some home brew lithium systems. If the OP has one them maybe setting it very close to the maximum charging voltage would do the job? Link to comment Share on other sites More sharing options...
robtheplod Posted June 17, 2022 Report Share Posted June 17, 2022 2 hours ago, magnetman said: My MPPT 100/20 units have exactly that function. The 100/30 and the 100/50 don't have it. Nor does the 150/35. Perhaps a useful argument for having individual controllers for each PV module. shame they dont do it on the bigger units - it would be far more useful as you'd deliberately over-spec your solar so you could plan a dump to the immersion (that sounded better in my head!).... Link to comment Share on other sites More sharing options...
magnetman Posted June 17, 2022 Report Share Posted June 17, 2022 I agree. I've got two liveaboard boats. One with 1.1kw of solar the other with 1.2kw and both of them do have a lot of surplus output. However due to a lack of washing there is not a true need for hot water. Definitely an interesting topic though. Link to comment Share on other sites More sharing options...
PCSB Posted June 17, 2022 Author Report Share Posted June 17, 2022 I got a reply from Immersun who are the company behind SolarImersion, sadly it seems a no go ... "Hi Paul, Thanks for your enquiry however IMMERSUN is only compatible with grid tied system as it needs to be able to detect exported power in order for it's mechanism to work." I wonder how it detects the exported power though ... Link to comment Share on other sites More sharing options...
Quattrodave Posted June 17, 2022 Report Share Posted June 17, 2022 (edited) 7 hours ago, robtheplod said: If only Victron and other makes made a dump load option that would make it so much easier to do........ 22 hours ago, jpcdriver said: I don't think the OP will be able to do that as the Victron MPPT 150 | 35 does not have connections for a dump load. Nearly all victron units have programmable outputs. Program the output go high when the charger goes into float (batteries charged) this can then switch a large relay to turn your dump load on.... Edit: I was just looking for the setting on a Smart Solar Controller so I could screen shot it.... I can't find it... I'm now wondering if its available on the Smart Solar Controllers..... Edited June 17, 2022 by Quattrodave Link to comment Share on other sites More sharing options...
GUMPY Posted June 17, 2022 Report Share Posted June 17, 2022 1 hour ago, PCSB said: I got a reply from Immersun who are the company behind SolarImersion, sadly it seems a no go ... "Hi Paul, Thanks for your enquiry however IMMERSUN is only compatible with grid tied system as it needs to be able to detect exported power in order for it's mechanism to work." I wonder how it detects the exported power though ... A coil on the main feed cable after the CU and just before the meter if it registers -ve current then you are importing if +ve then you are exporting. 1 Link to comment Share on other sites More sharing options...
rusty69 Posted January 5, 2023 Report Share Posted January 5, 2023 On 16/06/2022 at 18:05, PCSB said: I'm currently researching ways to use solar to heat the water on our boat. Currently have 550W solar, and a Victron MPPT controller 150 | 35 and a Victron Multiplus Inverter/Charger. The calorifier has a 1KW immersion heater in it which is only powered when on hook up. On days like today the solar has topped the batts up by mid morning and runs everything on the boat (other than the washing machine). I can even use the coffe machine and it copes fine. I'd like to be able to heat the water by using the excess solar, saves running the engine or hooking up when in the marina. I accept that some days it won't get me anything but on others it will or could. I do not want to mess about with arduino's and other "creative" ways of making the kit do what I want, ideally a plug and play solution is rquired. But I accept there may be some woring changes needed. I've found some domestic solar diverters on the web, such as SolarImersion, Solar i-Boost and Myenergi Eddi. Has anyone used one of these and did it/does it work? TIA Paul. Did your research prove fruitful in your quest for 'free' hot water? Link to comment Share on other sites More sharing options...
Alan de Enfield Posted January 5, 2023 Report Share Posted January 5, 2023 5 minutes ago, rusty69 said: Did your research prove fruitful in your quest for 'free' hot water? If you've got 'spare' (surplus) leccy then why not just plug the immersion heater into your inverter - just remember to switch it off before the 'Sun goes down'. Doesn't get any more 'plug and play' than that option. A 1kw immersion heater WILL take about 40Ah out of the batteries. Link to comment Share on other sites More sharing options...
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