Narrowboat Electrician - Immersion Heater on Lithiums

[@rangeofhills]

Hi. I thought about fitting an immersion, then I decided to go for an easier option and now have small 3kw heaters built into each tap. Only heat water as you need it. Hot or cold.. One tap just change the temperature by tapping your finger on the tap. These Chinese are clever folks.

[@narrowboatelectrician]

Yeah I can see the advantages, they would be high current but on for a shorter time. With the right power supply no issue at all.

[@steveohagan665]

Hay martin love this stuff . a bit over my head but love it . you know your stuff . Hope you and Fran are keeping well .

[@narrowboatelectrician]

Hi Steve, nice of you to say so mate. Every day is a school day, no one knows everything. Having the capacity to learn and figure out this stuff is key. Yes we are both well thankyou. Hope you are OK too.

[@keithweybury5212]

Hi Marty, love your electrical work and as always great explanation of the What, How and Why. Keith.

[@narrowboatelectrician]

Cheers Keith, glad to see you over here.

[@MmmMmm-cl6tc]

I fitted a digital regulator to my 1kw immersion heater so I can adjust accordingly to the sun .

[@narrowboatelectrician]

Yeah thats an option, With 2kw of solar and 500Ah of lithium, this guy can do what he wants. And thats exactly the way I designed the system at his request.

[@Erik_Sharp]

Hey Martin, this was just the video that I needed. Aintree is nearing the end of our build and we are having a Refleks stove with the back boiler to heat the radiators and calorifier. The engine heat will run through the other calorifier loop and a standard 1KW emmersion being the third way to heat the water. We are doing 1KW solar and 660Ah of Lithium and I questioned how we'd heat water in the summertime without having to: a. Be connected to shore power b. Run the engine c. Run the stove bypassing the rads (the stove would still get hot) I asked if we could run the emmersion from the batteries and they said no. Looks like we can.

[@narrowboatelectrician]

Hi Erik, a typical emersion heater connected in the calorifier is 1kw (check with Aintree) A bit of maths give 4A on the 240v side of the inverter ( you dont say what size the inverter is) at the 12v side that equates to 80A at the batteries so roughly if you had emersion on for half an hour, you'd use 40Ah from the batteries. Now as a one shot thats OK but you would have to be careful you didn't allow the emersion to keep coming on as (even with lithiums it would be quite a drain and deplete them. On a boat with standard LA batteries I would advise against it. Please consider joining the channel for continued technical questions, good luck with the build.

[@Erik_Sharp]

@@narrowboatelectrician Sub'd. Didn't realize that I hadn't. We are using the same as yours. Multiplus 2 - 3000VA. I am going to be doing home automation with an application called Home Assistant. I've been running it with my house for a while now. This will allow constructing automations such as: At 7am, when not on shorepower, the batteries are above 70%, and the calorifier temp < 35, turn on the immersion heater until temp > 40. Thanks for the advice.

[@davidcook380]

Great Stuff Martin

[@narrowboatelectrician]

Cheers David.

[@vonasi2]

A more elegant solution is to programme the inverter with an assistant to turn the AC2 outlet on when the batteries are full and then connect to a 1 OFF 2 selector where 1 selects AC1 and 2 selects AC2 (with appropriate RCD protection of course). This way you get solar dump as well as the possibility to manually turn on the immersion. Also regarding ring mains - if a boat has a Multiplus that has power assist then it needs a 2.5mm ring main so that it can at least use 32A of power. If it has a radial circuit then you can't use more than 16A and so can't benefit from power assist.

[@narrowboatelectrician]

You don’t see many 7kw inverters on narrowboats Chris. So 2.5 mm radials are perfectly fine.

[@vonasi2]

@@narrowboatelectrician You don't need a 7kW inverter - that's the whole point of Victrons Power Assist function! It will boost the shore power (or generator) supply with battery power to allow up to 50A combined. With a 2.5mm radial circuit you are limited to just 16A with that cable layout so you cannot use any benefit of power assist but if you have a 2.5mm ring then you can use the Victron power assist to go up to 32A because a 2.5mm ring is rated to safely carry up to 32A. I just assumed that with a Victron sticker on the back of your T-shirt you'd have heard about Power Assist!

[@havoctrousers]

@@vonasi2 2.5mm2 cable is rated for about 24A depending on environmental factors, so you can use a 20A fuse/breaker over a radial if needed

[@robtheplod]

Great channel, subscribed!!!

[@narrowboatelectrician]

Thanks for subbing. Hope you enjoy.

[@MicraHakkinen]

Those enclosures look like they were homemade with formex. Though they seemed surprisingly sturdy when you handled them. Still I'd personally prefer a metal enclosure, just for peace of mind.

[@narrowboatelectrician]

Hi Bart. These were made by the boatbuilder. I see similar on a lot of boats. I’m not much of a fan either. There always has to be a pragmatic approach when looking at existing systems. Otherwise you’d be rewiring every boat you came to with big bills for the owners. Safety raises the red flag every time though.

[@havoctrousers]

Could you have replaced that existing SFCU with a 30mA RCD enabled one? Interesting vid, thanks, the DC side is very interesting to me as I haven't done much of that.

[@narrowboatelectrician]

Hi Robin, thanks for commenting. What’s a SFCU? The 240 distribution box is not my favourite, but similar versions are in lots of boats. I fit a consumer unit if it a new install, in fact I have a split board in mine. Pre inverter and post inverter. The world of 12v is very different from domestic, so I hope you gain some insights.

[@havoctrousers]

@@narrowboatelectrician a switched fused connection unit - what's been used here as an isolator for the immersion heater. You can get one with a built in RCD for £10 in screwfix.

[@narrowboatelectrician]

@@havoctrousers ah right. I’ll take a look at that for interest and adaptability. The circuit is protected by an RCD already in the distribution box so wasn’t much need to add another.

[@havoctrousers]

@@narrowboatelectrician Ah, I misunderstood then. I thought you'd said the immersion heater was only protected when on shore power and not when fed from the inverter. Thanks for the response.

[@hydroesme]

Hey Martin, great video. I’m trying to do the same thing of running the immersion off grid but only by using excess solar power once the batteries are full. To do that I’m using a voltage sensing relay to switch on the 240v immersion when the voltage is above a certain threshold (currently 13.5v but need to play with the settings) And then as to not give the immersion full power, i am using a 4000W 220V SCR Voltage Regulator Dimmer Electric Motor Speed Controller Module To ‘turn down’ the draw of the immersion. Apparently this “solar dump” arrangement gives boaters hot water all throughout summer. One does need to adjust on very over cast days, but I’ll report back if it all works when I finish writing it up

[@forresteralex]

I have the same pannels lg bi are the way faward i only got 2 pannels on my 48ft narrowboat but i have 800 amps of lithium , with your vast knowledge of electrics can you reccomend a good windturbine for lithium batteries?

[@narrowboatelectrician]

Hey, how’s things. Yeah the LG BF are amazing, shame they don’t make smaller ones that would suit narrowboats. Wind turbines? I ran one for a year and was pointless to be honest, and I had it on a fairly high mast. They produce such a small amount I don’t think they are worth it except on the coast for starter battery maintenance. So I can’t recommend one obviously.

[@forresteralex]

@@narrowboatelectrician thank you so much for your reply i guess il have to take some of the mrs garden patch on the roof and add another lg pannel, i wish the tech for underwater turbines or the hydro generation was there it would living off grid on the rivers so much easier 😁 i have liked and subscribed and il share your channel keep up amazing work Alex

[@misamsung6191]

Wouldn't a solar dump be more useful? As it will heat the water until the batteries drop to a preset level and it will turn off the heater.

[@narrowboatelectrician]

Solar dumps are ok, but this customer wanted hot water on demand.

[@misamsung6191]

@@narrowboatelectrician Ah OK thanks. I was just wondering.

[@narrowboatelectrician]

@@misamsung6191 you have a valid point. He has a 100A mppt that I put in as well so there is plenty to go at.

[@darrenslater1913]

no shunt? or no comms from the bms's?

[@narrowboatelectrician]

I don’t understand the comment Darren. The Batteries have inbuilt BMS via Bluetooth.

[@darrenslater1913]

@@narrowboatelectrician hi mate. the screen wasnt showing battery data. so i was guessing lithiums with a bms that doesnt transmit data. if theres a 485/canbus port, its possible to make it show.