136. Beginners guide to narrowboat 12V electrics: batteries, inverters, chargers, solar and so on

#narrowboat #narrowboats #canal #canals #liveaboard #cruisingthecut
Following a few recent questions and comments from viewers, here is a beginners guide to how electrics work on a narrowboat. It may also have general relevance to people in campervans, motorhomes, caravans and RVs although there are slight differences but the gist is similar.
Please note I am not a qualified boat electrician and I have intentionally kept this superficial and left some things out so as to keep it simple for novices.
Please also direct questions not in the comments but to the 12 Volt Boating group on Facebook, which is at / 144684286108763
*NOTE*: this should not be confused with the very-similarly named, but different, "12 Volts Boating Group" (notice "volts" not "volt") which is also on Facebook and is run by someone else.
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Theme music: "Vespers" by Topher Mohr and Alex Alena, from the KZbin music library

[@philbrooke-little7082]

Please if you want to join the facebook 12 volt boating group could you either belong to other boating groups or have friends in it or answer the question saying why you want to join. The reason is that I try to keep it as focused and relevant as possible and so try to restrict membership to those who really have an interest and reduce the chances of Trolls and Advertisers. Thank you.

[@alanboman8860]

I'm an electronics engineer and your video is the best "12 Volts for Beginners" ever. It should be mandatory viewing for all the so-called boat/caravan/RV experts "out there" - and there are so many - !

[@CruisingTheCut]

Thank you!

[@CallmeRogerRoger]

I consider myself fairly well versed in electrical systems. I say that to provide background for my next comment. This was a VERY EXCELLENT beginner's tutorial. You've put a lot of effort into the script and production of this video and it really shows. Tremendous effort and wonderful outcome. Thanks!

[@CruisingTheCut]

Cheers :-)

[@brianc5356]

As an electrical engineer, renewable energy guy who deals with off-grid solar systems more often than he wants (mostly because most casual users are idiots and need my help to keep from murdering their batteries), you've done an outstanding job of explaining this for the layman. You indeed "get it". I salute you, Mr Johns. Clearly, you will always have the energy you need. Cheers!

[@CruisingTheCut]

Thank you

[@Nerd3927]

I am a ships electrician and fully approve of all the info in this video. Well done !

[@Nerd3927]

Alien Creation Yes that is true. The art is to leave those details out. It is only confusing people...

[@WogChilli]

Conventional current flow; electrons flow + to - Actual current flow; electrons flow - to +

[@NorfolkPilot]

As you admit that you’re a non technical person as far as boat electrics are concerned, I was expecting lots of mistakes, and hoping there would be no dangerous advice! Actually you did very well, and although I’ve been into electrical work (non boat) all my life, you presented it far better than I ever could hope to. Well done. Still hoping to get my own narrowboat one day!

[@mattevans-koch9353]

David, Well done tutorial on the basics of boat electrics. As a retired electrical engineer it is good to see this subject covered well by actual users as we engineers are not always the best instructors and tend to use shorthand terms in our explanations. Sometimes we (engineers) forget that not everyone is as interested in our subject as we are and having a layman such as yourself give a good explanation based on study and experience is important and very helpful. Keep up the good work on the vlogs. Have a good week.

[@CruisingTheCut]

Thank you!

[@sgit1]

BANG! . . . in all its glorious colors. It's one thing to have knowledge and quite another to take that knowledge and communicate it effectively. Well done.

[@howieb2001]

I'm 66 and don't have a narrowboat but am working my way through your videos from the beginning. Most enjoyable. Having reached this one I now have more understanding of electrics than I've ever had before. Thank you.

[@courierdog1941]

As Always a simple yet excellent Blog on Narrowboat Electrics. and this does come from an Engineer. Cheers

[@CruisingTheCut]

Thank you

[@GregVirgoe]

Considering that was a beginners guide to electrics you cover a lot of really valuable information in a very short video and all spot on! Nice one David, very well presented too.

[@floydbertagnolli944]

I’ve been using and teaching electronics for many years. Your explanation was excellent for beginners. Well done.

[@CruisingTheCut]

Thank you very much!

[@lukasreiser4669]

I'm an electrician and you explained everything very well. And like always I could understand everything, bc you speak like I learned it in school :-)

[@williammarshall1676]

After tonnes of research and a lot of swearing, this vid became the ultimate "penny drop" moment. Bravo sir!

[@CruisingTheCut]

Glad you enjoyed it!

[@ChrisTheSparky]

As an electrician this was an excellent put together video and one I've been waiting for.

[@lesleycouch6557]

Brilliant - this has gone a long way to de-mystifying the weird world of boat electrics for me. Thank you!

[@llessibm]

Even though I kind of knew most of that I have to say that you really put that across well - a well packaged guide that I’m sure will be very useful to many people 👍

[@michaelchrabot8722]

i love the graphics...keep it up!!!!!!

[@stevemusgrave2000]

Spot on David. Covered everything a 'non' electrician should know (layman). Pretty much anything after your explanation should be done by a qualified person. It's dangerous stuff as you've already said. Brilliant well done.

[@pootle2768]

That was really interesting and very clearly explained. It reminded me of Take Hart!

[@ladygardener100]

I don't think David is quite that old .......... his TV is in colour!

[@CruisingTheCut]

He certainly is. I remember Take Hart from my childhood very well!

[@wildlifewalkswithcountryge749]

Boy David, can you hold an audience! I haven't a clue what you're going on about, but I still watched it to the end! 🤦🏼‍♂️More please 👍

[@radioguy534]

Ever thought of taking up Electronics as a Career? You have done so well at explaining this, I have worked all my life in Electronics and could not fault you in anyway. Keep up the good work, love every Vlog you turn out. Allan NZ

[@JMVideos7676]

Wow, fantastic tutorial on the electrical systems in the boat. Very well presented and I didn't feel like you were talking down to the audience.

[@CruisingTheCut]

Much appreciated!

[@ncplantdoctor]

Very good, Mr CTC. Before I watched this video I had a good understanding of the physics of electricity and afterwards I still understand everything. You failed to confuse me. Very good. I also need to mention that you picked a very appropriate title for the video. I currently cannot think of a better one.

[@stephencoster9532]

Hiya, very well done, thank you. As an ex-spark I'll only say one point, a fuse just protects the cable/wire after it, not what you may have plunged in. Steve...

[@sylviapage8572]

Excellent explanation. You should have been a teacher! Thanks.

[@elainebines6803]

Excellent - so many of us need to be educated on this - general jist will do, layman's terms is what I need👍

[@andyward8336]

When I was 14 I had a 12v car battery blow up in my face due to it being on charge and me accidentally shorting it out with a spanner earth to live . Luckily for me there was someone near by with a garden hose but still in the few seconds it took for them to realise all my clothes melted and I looked like I'd got bad sunburn for a month and I couldn't hear for 2 weeks . There was only the bottom of the battery left and my face was only a foot away from it , on that day I may have been the luckiest kid in the world .

[@CruisingTheCut]

Oh my; lucky indeed. I'm going to pin this atop the comments so others can hear the story. Cheers

[@jeffbrewster6658]

My God , I think I’ve got it ... very well explained for the not so bright ones such as myself , many thanks .

[@timp3931]

I once installed electronics on boats as a job and this is an excellent video! I did not know steel boats had a negative ground, most boats in Canada are obviously fibreglass or wood. Great that you advised that we do not use the entire capacity of the battery bank. Note that the only pumps on my 24 ft. sailboat are operated by hand!

[@rodritchison1995]

This would have been handy forty-five years ago, when I started my railroad career in the signal department. Took a year, without help, to get to the end of your fifteen minute vlog. Well done. And yes, I did blow a hole in the blade of a long screwdriver by dropping it across a 12 volt battery. Noise and flash to match Hollywood's best pyrotechnics.

[@1968wrighty]

Well done video you shook be a technical teacher as it was easy to follow and explained well.The steel boats I work on are what's called "above earth" where all the electric wiring and switches are double poled so there are not any stray voltages to the hull

[@edwiser3547]

Hi David, I am an ABYC certified marine electrician and want to applaud you for making such an informative video. You made some excellent and very important points. There is a lot of talk about lithium but people generally do not understand there are several types of lithium are not all are suited for a boat. Also, the charger, discharge, and storage characteristics of lithium are so different from conventional batteries that installing lithium requires a complete battery management system designed for them alone.

[@CruisingTheCut]

Thank you. Yes, lithium would need its own video (or more!) I reckon

[@wheels9341]

Excellent job! I'll be recommending this clip to many of the boaters I work with. Many thanks.

[@CruisingTheCut]

Cheers!

[@joerogers4227]

One of the best description of a combine ac and dc systems. This also applies to most RV's in the USA. I am well versed in both AC and DC. One item to add to future discussions is that all batteries are not equal. Example Boats and RV nromally use Deep Cycle Marine (of RV ) batteries. Automotive batteries are built for a quick heavy current load for the engine Starter and RV have a "house" battery for the 12 VDC systems such as water pump, lights, even some TV's. Keep up the good work, Joe in Arizona, USA

[@matak99]

Well. Now I am current on 12V boat electrics. Thank you.

[@doonsbury9656]

You made a great job of explaining everything in real laymen's terms & in a way that was easy to follow. I imagine many of your subscribers will get a far better understanding of their boats electrical system, how it operates....and much more importantly....how to ensure that it doesn't let you down (Or burn your boat down! ;) )

[@thekitowl]

Great Vlog. I came to your channel around no 60. I enjoyed it so much I’ve gone back & watched them all, adding likes as I went . Keep up the good work.

[@nbflyingfox4672]

Nice one David a very straight forward way to describe the battery system in a boat plus great graphics.. not too technical and given out in layman's terms easy to understand...

[@MalcOfLincoln]

Well David, I agree with many of the other comments. Your ability to explain things simply and clearly are excellent. I'm sure this video will help a great many people understand their boat electrical system. Although I think you touched on it, I think the only thing you missed was that you need to use electricity SPARINGLY i.e. turn the bloody telly off and read a book lol.

[@Mark-xm4sc]

Nice video. I’m a novice and knew everything you have said. However, you said it clearly and the sketches were great so I feel like I’ve learned something. You clarified what I already knew and explained it in such a way as to make it even more understandable for me. The only thing I didn’t really know before was why earthing to a boat hull causes corrosion. I hope you do a vid on lithium ion batteries one day as I haven’t a clue about them and have never investigated. Anyway, thank you for the informative video. I appreciate how clearly you explain things.

[@anthonywstanton]

Well done sir! Positively electrifying!

[@tonyblackmon6356]

You explained it so well that you make it sound simple. I hope people will take heed to what you said. You explained it very well. I learned about the OHM's Law back in 1956, before I got involved in communications. You surely have a nack for teaching the basics.

[@dianeryan-austin834]

As prospective boat owners, we found this extremely helpful. Thanks ever so much!

[@shleep2000]

Thank you, really very enlightening. One of the most useful videos I've seen about boats. Thank you Sir and may the force be with you!

[@totallysimulated944]

Great video, I think you've found your new calling in life. Best instructional vlog I've seen in ages. Splendid job old boy !

[@stilcrazychris]

Very nice drawing David. I loved the video. When my Dad built are houseboat, solar power had not hit yet. So he ran both 110v & 12v. 110 bc I live in the US. So when we was out on the lake or coving out on shore we would use 12v. & when we was connected to shore power we would turn the 110v lights on. He had them marked so we didn't forget. To me it was a neat setup, but I was only 12yrs old & 42yrs old when he past. So I didn't really get to ask a hole lot. Bc it was always there. And you don't think about that stuff till it's to late. Thanks for the neat info, Chris

[@CruisingTheCut]

Cheers Chris

[@ccooper8785]

Thanks for a very enjoyable and informative video. For some reason when watching your brilliant drawings, the music from "Vision On" was playing in my head.....

[@narrowboatmum165]

Thank you for this video you have saved me lots of work. Emma from Narrowboat Girl is homeschooled and intended to teach her some basic electrics. Now I have a perfect lesson for her. Thank you Narrowboat Mum.

[@pholland6643]

natural learning

[@mikepowers8607]

Speaking as a mechanic at a Chevrolet dealership...WELL DONE! You made what can be a very confusing topic easy to understand and entertaining as well. WELL DONE SIR! Go reward yourself with a G and T!

[@SNAKEPIT359]

Thank you for that. That was a very impressive breakdown of the electrical workings of a narrowboat. I'll have to go away and study this more in depth. Thanks again for sharing.

[@chrishewitt4220]

Why oh Why can't I like more than once! Great explanation. Thanks Dave.

[@CruisingTheCut]

Thanks Chris!

[@mischef18]

Great video bro, everything in it can be linked to land based things like caravans and or motorhomes whether home built or custom made also. Thanks for going to the effort of doing this video. ATB.

[@jurgenahaus4300]

Thank you so much for this vlog about batteries. You ecplained so cleary that even I understanding the working of batteries better now 😊😊 I surely do hope you make another vlog about batteries. I wish you a very nice evening

[@ChristieNel]

A most comprehensive overview of boat electrics. Proper job.

[@calzenner830]

Brilliant piece! Job well done.

[@geoffclarke1974]

I've just rewatched this and it's a great video.

[@aaronhorn6849]

As an electrician, very well put. I wouldn't call it glossed over more along the lines of a satin finish! =]

[@rickjasper7233]

For a first time boater this was the entry level on how canal boats electrics tick a great help. I personally found the calculation on how to work out what you are connecting to the batteries really helpful and hopefully this will stand me in good stead for the future when we are moored up running just off the batteries. Thank you.

[@johnbraine5940]

I've been following Jono (Journey with Jono) who has a Phd in boat electrics and is very informative. The only problem there is that I have failed to grasp what on earth he is talking about sometimes! Your exposition made things much clearer, especially the issue of amps and amp hours. :-)

[@alejandrayalanbowman367]

They do say that a picture is worth a thousand words; or at least Fred Barnard said it back in 1927.

[@ladygardener100]

yep, Jono gets carried away, but two things I learned 1] they need to be kept reasonably warm [they move in with you.] 2] avoid Lithium batteries, unless you really understand and love his lithium vlogs.

[@JourneywithJono]

No PhD here! David has explained it very well.

[@melike1984]

most enjoyable youtube thank you!.ive just sent you a payment as a token of my appreciation for the youtubes that you produce that I​ enjoy watching

[@CruisingTheCut]

I have received it and sent you a reply by email - thank you indeed :-)

[@waynepeeples3916]

Good for you, David Johns! My wife and I bought our 1st houseboat 9 years ago, upgraded a year later and got our floating house barge 2 years later. Now, after nine years of living on houseboats, we are absolutely hooked on the floating lifestyle. Our son has caught the school bus at the end of our pier from kindergarten until now when he has finished the 8th grade. If you ever get tired of it, do like we did - get a bigger boat. Our first one had a total living space of 8ft x 20ft. Now we are happier with 14ft x 40ft. Our slip rent includes water and electricity and it is much less expensive than any apartment anywhere. We live in Mississippi, USA. We also have a big golden retriever, and the Ross Barnett Reservoir is her back yard, where she greets all boat passersby with a healthy yapping and many of them cheer back and call out her name, Ginger. Thank you for sharing your video. If you do Facebook, check out #lifeontherossbarnett.

[@blacklablover2982]

Brilliant! To me and many others this subject is a black art onto which you have thrown some light. I wholeheartedly agree with the comment regarding the Facebook 12v page and in particular Phil Brooke-Little who is a fantastic source of information and generous with his time and expertise and very helpful as are others on that ‘forum’.

[@TheNarrowBoatToTheDeepNorth]

Great Vlog! it was good for me to recap some of the things we've still yet to finish. Thanks for psoting. Best, Martin

[@Dozz70]

First Class Video....very informative! Thank You Dave

[@thomasbernecky2078]

I'm glad to see it looks like your drawing skills have now progressed beyond crayons. This will be helpful for my looking at NB ads from a North American Luddite electrical perspective.

[@jayoneill1533]

Thank you David, for walking us through the basics of boat electrics. Nicely done.

[@mikeelliott2736]

This is a really good simple introduction to boat electrics. Well done, David!

[@dmcarpenter2470]

Splendid electrics video. Yes, I am still grinding through the vids, one by one. Still enjoying myself. Thanks.

[@adamshaw1032]

Good to see you making another brilliant vlog on cruising the cut! About time I've been waiting for a new episode! Thanks a lot and all the best!

[@malcolmolding2804]

We’re new to narrow boating and the electric system looked like a minefield. Thanks so much for your simply explaining it to us in an interesting and informative way. ;0)

[@JamesYoung61]

Great video David, I think that you pitched that just right and covered all the salient points.

[@MrWarneet]

The girls did a great job of how a gulper works last week... I'm intrigued at the unique issues boats have compared to say a caravan or RV...

[@darlenecarman303]

What a great job in explaining electrics, batteries, etc. It was a puzzle to me before.....

[@WeaverBird64]

That was so helpful. I've looked up information on batteries previously and just ended up totally confused. Thank you so much.

[@paulsedman7876]

got to save this vid, ill be going over it again and again and again, very very helpful .

[@lilbatz]

I don’t even own a boat and am saving this vid. Greatly explaining David! 👍🏼

[@brettjohnson6807]

Excellent video as usual! Keep up the good work!

[@robcall5182]

another superb presentation David,.. i'd consider buying a TV license and watching it if you were presenting a program on it. Alas it appears the general UK population is happy to pay to watch repeats of programmes made decades ago. I'm glad you joined the internet.

[@charlescurtius2261]

this may be the best intro to marine electronics for the non professional ive ever seen. well done :) by the way if you own a boat i would recomend a copy of Nigel Calder's book Boatowners Mechanical and Electrical Manual. dont buy the expensive hard back though couple projects in the engine space and it will be covered with greesy oily finger prints :)

[@mallow173]

Liked that very much 101 level....just going to wait patiently for 102! thanks!

[@andyparsons6293]

Wow! Thank you. Electrics have never rocked my boat but you made it so clear here, the diagrams solidified your words instead of them going straight out my proverbial other ear in a ridiculous jumble of non-retrievable , fragmented and distant memories.

[@gaibutler3254]

Thank you very much for this. I did have a reasonable understanding of the power system but this style of presentation cements the basics. The description of the calculation for energy consumption was particularly helpful - I’ve never been confident that I had that right, looking at it in written form as you explained made it so clear and simple. My husband set up the solar power system for our caravan, as for him explaining it to me, well, I handed him his notice as an instructor decades ago.

[@jimmyco123]

Thanks so much - an excellent crash course!

[@karljoachimgoll]

Probably, one of your best VLOGs - and, in private, that means quite something... 🔌💡

[@pascalcoole2725]

Fully agree

[@heathernorris539]

That was a very interesting and informative video, thankyou David.

[@davidr1431]

Thanks for this. Really accessible and interesting.

[@FairuzOnn]

Happy new year David, i'm currently at this episode right now, more precisely 142/163 of your vlog plus not a vlog, really love your not a vlog videos, it's like a tranquilizer LOL. Anyway wish you have a great 2019, cheerio.. cherio... cerio.. how to spell that :p

[@davidjones8680]

I do get to do a fair bit of work with12v & 24v stuff on cars and lorries, and I also look after and maintain some 48v & 72v electric forklift batteries at work. However, it seems to be a whole different world when it comes "floating" electicals. I have found your explanations very enlightening and educational, and its made me want to find out more on the subject. Many thanks again David, I have got really hooked on following your channel.

[@michaelshelton462]

From your timidness of electrical thingamajigs at the onset of your adventure to your journeyman knowledge of nautical electronics, it has been a joy to watch your mechanical aptitude flourish. Thanks for the adventure!

[@pholland6643]

Good explanation David, missing your cruise videos but understand you have other things on your plate.

[@briannamyo]

Very helpful video, thanks for this. At the moment I'm dead in the water... literally! I've no Internet access of my own at the moment, have to use other access points like friends and cafe's. Can't wait to get my electrics on the boat done. I'm learning how to do all the necessary wiring myself. It's a hell of a job but I think I can do it.

[@chucksterock]

That was a well done informative introduction. You were very clear and accurate in your descriptions, and particularly your warnings. Well done from an engineer.

[@CruisingTheCut]

Thank you

[@BillyTpower]

I like KZbin in so much as a "nugget" sharing platform, I'm very well versed in automotive 12 volt and solar systems but I learned from you today that 12vdc on a boat should not be grounded to the hull in the way a car does the frame. ty for sharing.

[@CruisingTheCut]

Hmm, I hope I didn't say that. The return path of the 12V system shouldn't be the hull for sure but the -ve terminal is indeed strapped to the hull, separately from but near to any mains earth (which would also be grounded to the hull). And the engine has a ground to the hull as well.

[@BillyTpower]

@@CruisingTheCut I must have paraphrased the explanation wrong. my bad. kzbin.info/www/bejne/aoaxg2Wqeap0hcU

[@steverayner7605]

Wow! Such a wonderfully clear and concise presentation of the basics of what is an INCREDIBLY complex topic. So VERY well done David.

[@CruisingTheCut]

Thanks Steve!

[@danwelch25143]

Hello, I love your blog and appreciate the work you put into it.....Now my comment my father was and industrial (mining) electrician plus I lived next door to an very qualified electrician for 40 years and they could not explain this as well as you did. For that I am very grateful!! Dan

[@CruisingTheCut]

Great! Haha, thank you

[@donfoster5576]

Very nicely done. The distinction between "volts" and "amps" is often confused by those less familiar with physics or engineering. Your analog of voltage as pressure is perfect -- one can have equally high water pressure in a tiny pipe or a huge pipe but not the same flow. Likewise, the analogy of amperage as flow is perfect and correct... think of the current in a wire much like the current in a river. A small stream cannot provide the same flow as a huge river, just as a thin wire cannot deliver the same flow (current or amps) as a thick, heavy wire. Another bit of trivial technobabel... an expression of "watts" is an expression of power (or power consumption), just as we might describe the size of an engine by its horsepower. In fact, 746 Watts equals 1 horsepower. So, a 1000W microwave actually requires about 1.35 horsepower to run. And this explains why a bigger electrical motor requires fatter wires than a small motor.

[@WildeFyre69]

An informative and well-presented video Sirra! Cheers!

[@HaskellMoore]

An absolutely excellent tutorial!

[@johnbrookes2196]

Great presentation David.

[@Earthwatcher57]

Brilliant informative video. I'll be coming back to this again and again, and thank you for the Facebook link, great example of how people in this community spread the help and expertise. If only life off the water so communal. It'll be one of the best chapters of your book which is surely on its way.

[@CruisingTheCut]

haha, I hate writing!