3 boats with battery charging ... sauna with lights and music .... couple of LED floodlights ????

[Refueler]

Its a long way to cable electrics to bottom of my garden .... plus the need for electricity both sides of canal.



On the left you can see the post that carries cable from BBQ area just out of shot .. to the pontoons. At present you can see the white cable hanging loose which then goes over the speedboat .. into the water and up other side to provide power to charger on the MoBo.

This is purely temporary.

Pal and I were talking about piping a cable across the channel ... but then an idea flashed in my mind .... Solar ? A complete independent Solar setup ??

Title says it all :

3 boats to run their chargers (3 x 10A 12v) ... + couple of lights and a music box in the sauna (its wood burner for the sauna) .. + a couple of LED floodlights ...

A solar system with storage battery ... ?? What size given that in reality - as long as the storage battery is sized sensibly - the solar system will basically be charging the boats mostly.

I'm thinking 2KWh solar + 2KWh Inverter / battery hybrid .....

???What would you install ??

 

[rogerthebodger]

When I was in Durban we had no mains power, so I set up my boat with solar and all wife's comforts to run off 12Vdc including a TV and computer and an inverter for power tools and wife's equipment including a microwave as we lived onboard during our visits

So solar is perfectly viable to keep the power and batteries charged batteries can be kept charged just using solar and regulators for efficiency

 

[Refueler]

The question is really how much power do I need to produce ...

Local shop has small LED floodlights that are solar powered and with PIR ... meaning I don't have to incl in the overall power total.

Music can be via 12v .... lights as in a boat 12v ... just leaves the boat charging --- also 12v

Nice to have 240v - even if only limited watts.

 

[ylop]

Key question for battery size is obviously how long between "sun light" that is > the battery drain. e.g. are you taking summer only? Do you get weeks at a time when there would be less going in that going out?

Another left field idea - is it actually easier / cheaper to simply plug in a bluetti style battery pack/inverter combo - some have solar input too. But if it is occassionally undersized, or you need to boost it - you can pop it back the house to charge?

 

[Refueler]

Daylight hours here range from 18hrs in 24 .... down to 6hrs in 24 ......

The only continuous drain on system would be the boat battery chargers - which in reality will usually be drawing very little ... float. Music and lights would be only once or twice a week at most for an evenings sauna / get together.... more likely once a week.

 

[Refueler]

Talking with pal - he suggests just rig up a 12v Solar system same as would on a boat ... with a modest inverter for limited 240v fed from the battery bank ..... run lights / music etc on 12v ..

Solar + MPPT + Battery Bank + inverter

 

[Refueler]

Had long discussion with the Solar guy who installed my House system ... very good. But the system I want at the channel is too small for his usual setups .. he would be looking to create a 4KWh system ... which would be well over the top for whats needed.

Back to the 12v idea ....

On eBay - just as example - a 300W (probably half that in reality) ... :

Pardon our interruption...

Comes with panels, stands, controller, leads etc.

Then I could add a couple of LiFePo4 batterys ... ~ 100AH to give 200 AH storage ?

LED lights and music run from 12V ... the outside flodlights can be independent own solar powered ...

But this does not provide the 240v for the boat chargers ... ??????

 

[ylop]

Refueller I have in my head a few figures (which may or may not help). Good panels can get 200W/m2 in optimal conditions. I’m guessing that number might be a bit dated now and very good panels might be available for the right money that would give 300W/m2 as per your eBay advert.

Edinburgh (probably not that different to you?) gets a little under 100W/m2 of average sunlight - assuming your panels are facing the right way, not in shade etc then it’s impossible for them to make more that this - in reality it will be significantly below. At peak summer you can get 10x this. Most panels probably only manage to convert about 20% of the available energy to electricity.

Do you really need 200Ah of battery? Especially LiFePO4 where it is “all” accessible rather than only half?

Here’s a different thought - stick 5-10W solar panel on each boat (no need for controller when so small) and it will stop the natural self discharge. Buy a portable “power pack” for the music/lights and just take it to the house to charge?

 

[PaulRainbow]

Had long discussion with the Solar guy who installed my House system ... very good. But the system I want at the channel is too small for his usual setups .. he would be looking to create a 4KWh system ... which would be well over the top for whats needed.

Back to the 12v idea ....

On eBay - just as example - a 300W (probably half that in reality) ... :

Pardon our interruption...

Comes with panels, stands, controller, leads etc.

Then I could add a couple of LiFePo4 batterys ... ~ 100AH to give 200 AH storage ?

LED lights and music run from 12V ... the outside flodlights can be independent own solar powered ...

But this does not provide the 240v for the boat chargers ... ??????

Foe he same money you could buy a quality 450w domestic panel and a Victron MPPT controller.

Not sure the LFP makes sense here.

 

[Refueler]

Refueller I have in my head a few figures (which may or may not help). Good panels can get 200W/m2 in optimal conditions. I’m guessing that number might be a bit dated now and very good panels might be available for the right money that would give 300W/m2 as per your eBay advert.

Edinburgh (probably not that different to you?) gets a little under 100W/m2 of average sunlight - assuming your panels are facing the right way, not in shade etc then it’s impossible for them to make more that this - in reality it will be significantly below. At peak summer you can get 10x this. Most panels probably only manage to convert about 20% of the available energy to electricity.

Do you really need 200Ah of battery? Especially LiFePO4 where it is “all” accessible rather than only half?

Here’s a different thought - stick 5-10W solar panel on each boat (no need for controller when so small) and it will stop the natural self discharge. Buy a portable “power pack” for the music/lights and just take it to the house to charge?

Superanne has a 10W panel on the pushpit rail to a dual controller - feeds both batterys (LA 80AH each). But struggles .. probably because I'm asking a small panel to charge two batterys. She also has the Mastervolt dual charger fed by 240v. But batterys have suffered and one at least needs to be replaced. I have a couple of larger folding panels in box that I bought to hang over the guardwires of my larger 38. I keep meaning to swap out that small panel and use one of these ...

The MoBo has two panels in parellel but are laid on cabin top either side of companionway ... shaded by the cockpit hood .. cables too short to move outside. Whoever put them onboard was not so clever !! Fine if hood folded back .... but useless when hood closed. Batterys are maintained by Victron Smart BT charger fed by mains 240v.

The 38 - I'm not worried about - the panel needs replacement - its old .. but she sits in marina connected to shore and has Victron Smart BT charger.

My main task is to power the sauna and 'entertainments' ... secondary to sort the boats ...

I can of course stay with present system - just change the cross channel cable to longer heavier - so it sits on bottom of channel allowing boats to cross above it. But still have the issue of the sauna supply.....

 

[Refueler]

Foe he same money you could buy a quality 450w domestic panel and a Victron MPPT controller.

Not sure the LFD makes sense here.

I'm trying to keep the boats charged by existing systems on board ... which are mainly based on 240v supply to Victron / Mastervolt dual chargers.

I could hang panels on rails etc - but TBH - I am trying to avoid the hanging out panels - then taking them in ... stowing etc ...

The issues foundation comes from the sheer distance cables would need to run ... and that I have requirement for power BOTH sides of the channel.

If really needed - I do have a 3Kw Generator .... but who wants that drumming away ??

There is also the matter of Latvia being in the EU ... but that does not mean we have all the products here available ...

 

[Refueler]

Looks like I shall be going back to trenching a cable.

 

[rogerthebodger]

Looks like I shall be going back to trenching a cable.

Could you run the cable over head ar a height above the mast

 

[Alex_Blackwood]

Looks like I shall be going back to trenching a cable.

Nigel, If going down the trench route, use some sort of ducting. That way you can add or pull out cables , water pipes etc. as required. I would be inclined to run to a distribution panel at the top of your channel and then cables to outlets either side. I don't know the regs for cables in your neck of the woods but in UK if you use a "Cable management system" i.e. ducting, you don't need armoured cable.

 

[Refueler]

Piped cable here is just heavy duty domestic for sheds / simple stuff ... but double sleeved semi armoured for garages / workshops etc.

Its adequate in this situation to use decent section domestic into literally water-hose buried ...

I would put a riser with exterior socket at head of channel ... then split of to either side with again similar piped cable ...... with risers and sockets as needed along decking / sauna etc.

 

[William_H]

Hi Nigel
I think your experience of domestic solar should tell you if solar alone would be adequate. If not adequate in winter then you must resort to mains supply in some form. I would be inclined to low voltage cabling of power to avoid rules re mains cabling licensed electricians etc. 24 v might be better than 12v . Not keen on mains cable under water.
However if you go for solar. your mate who provided the domestic system might be willing to supply a single panel like 350w at 40v no load. The over supply might make winter work better. it will need a MPPT controller of course.
I have bought 4x 50AH of these Google Search
Both sets 24v in mobility scooters. Cheaper than LA and more capacity. Also light in weight such that you could carry up to house for charge from mains in winter. Half the weight of LA.
As a matter of interest I charge the Litime 24v off 2x 10w panels direct relying on the BMS to cut off charge when full. I fitted a power transistor and zener diode across the supply to limit voltage to 30v no load. Just because battery data requires 15v source. ol'will

 

[Alex_Blackwood]

Piped cable here is just heavy duty domestic for sheds / simple stuff ... but double sleeved semi armoured for garages / workshops etc.

Its adequate in this situation to use decent section domestic into literally water-hose buried ...

I would put a riser with exterior socket at head of channel ... then split of to either side with again similar piped cable ...... with risers and sockets as needed along decking / sauna etc.

I would be inclined to use a small consumer unit, in a suitable enclosure, you can then easily isolate supplies if required. Or even just an RCBO and Circuit breakers as required mounted on a bit of DIN rail in a box.
PS Make sure you use big enough cable to allow for expansion. You will need it

 

[PaulRainbow]

As a matter of interest I charge the Litime 24v off 2x 10w panels direct relying on the BMS to cut off charge when full. I fitted a power transistor and zener diode across the supply to limit voltage to 30v no load. Just because battery data requires 15v source. ol'will

I have said it before, using the BMS to control charging is an extremely bad idea, i hope no-one else reading this thinks it's OK to do, please don't.

 

[PaulRainbow]

My previous boat, that i lived aboard for several years, was fitted with 3x110Ah leisure batteries and 2x100W solar panels. During the Summer i was self sufficient with electricity, although cooking was by gas.

A 450W panel should be more than enough in Summer, but if not, you only have to add another panel, costing £50/£60, providing you buy a controller that can handle that much power, just in case. A small inverter solves the 240V issue.

In the Winter you're not likely to be having music outdoors or having saunas, you just need to trickle charge the boat batteries.

Stick with LA batteries, although they are not perfect in your Winter temps, LFP will not tolerate them for charging, unless you fit heat mats etc.

 

[bedouin]

Have you considered wind rather than solar? Probably more reliable in Winter