Small craft Solar/battery kits

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Jemima Puddleduck

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Hello,
I've looked around the forum but can find any related topics.

I'l looking at purchase an old Hunter Delta 25 that needs the electric power/supply sorted as it has no battery, nor controller/charger. This is my first big boat, I'm coming from dinghy sailing. So my knowledge of electrics is minimal.
My power requirement will not be huge. Mostly harbour sailing and a bit of weekend costal cruising. So I'll need enough power for navigation instruments, navigation lights, anchor light, stereo, usb charge for phone and a handheld VHF and a small tiller autohelm for longer passages. I was hoping to be able to afford a small, light weight LiFePO4 battery, or another viable Lithium technology battery (it seems to be a minefield). I won't have main power where I'll be mooring (dry mooring) so the only source of power for charging will be the solar panel. I was wondering if there are kits that have all the main components required included. I've found the a kit without battery from Renogy 200W 12V Flexible Solar Marine Kit w/ 20A Voyager Waterproof Charge Controller . I'm not sure how good these are as they appear to be more for land based use rather than marine. Also I'm not sure what sort of battery I'd need to pair with it. It goes without saying that my budget is limited... Can any one offer any advice?
 
Why not just a bog standard leisure battery? approx 60AH and a 30£ solar trickle charger? If it's just weekend use then the trickle will keep I right during the week.
If you have an outboard you could charge up battery off that now and then to maintain capacity?
 
Jemima Puddleduck said:
My power requirement will not be huge. Mostly harbour sailing and a bit of weekend costal cruising. So I'll need enough power for navigation instruments, navigation lights, anchor light, stereo, usb charge for phone and a handheld VHF and a small tiller autohelm for longer passages.
Click to expand...
Are the nav lights LED?
Do you not need cabin lights?
The autohelm might be quite power hungry
You might be surprised just how much juice all that lot actually uses on a weekend? Good news is you don’t have a fridge on the list - but you might want to think in terms of future upgrades, could a cool box, diesel heater or other power hungry stuff feature in the future?
Jemima Puddleduck said:
. I've found the a kit without battery from Renogy 200W 12V Flexible Solar Marine Kit w/ 20A Voyager Waterproof Charge Controller . I'm not sure how good these are as they appear to be more for land based use rather than marine.
Click to expand...
I have a 120W flexible eco worthy panel which came in a similar kit to the above charging bog standard AGM batteries. Seems to work ok and so far has not died from being used at sea. It’s not my only source of power.
Jemima Puddleduck said:
Hunter Delta 25
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Presumably it has an engine, but since you don’t mention that I’m guessing it’s pull start outboard?

Have you got the space for a large panel? Shadows affect panels. Would two smaller panels be more flexible? Would rigid panels be more efficient.
 
You don't say whether there is anything electrical already in the boat. If not then you will need to fit a 12v distribution panel to service your lights, instruments usb nav lights. As suggested the simplest way of providing power is a standard lead acid or AGM battery of around 70-80ah and as much solar as you can fit. Lithium is an alternative and may even be cheaper as you need a smaller capacity because you can safely use a larger proportion. complications only arise if you have charging from an alternator, but just from solar to top up when you are not there is no problem
 
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ylop said:
Are the nav lights LED? not sure but i’ll change them if they are not
Do you not need cabin lights? yes, but not much. i’ll bring a camping light. happy to rough it
The autohelm might be quite power hungry. interesting, i’ll have a look. will only be fair sailing on autohelm
ut you might want to think in terms of future upgrades, could a cool box, diesel heater or other power hungry stuff feature in the future? not much as mentioned, mainly roughing it
Presumably it has an engine, but since you don’t mention that I’m guessing it’s pull start outboard? yes, i’ll have 2 small 2 stroke outboards i won’t charge off them. want to keep it simple. if i want more i’ll upgrade the whole boat

Have you got the space for a large panel? Shadows affect panels. Would two smaller panels be more flexible? good point, i’ll measure it up when viewing it this weekend
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thanks
ylop said:
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Your needs are modest, so they should be easily fulfilled.

Your package solution looks reasonable, providing you have room for the solar panel. The included charge controller is a quite basic PWM controller and is low cost. The main limitation is that while it has a lithium setting, this will not be ideal for all lithium batteries.

It seems the Renogy panel is available from the same site for £170. This leaves around £100 for the controller and cables. Team this solar panel with one of the small Victron controllers, such as the Smart Solar 75/15, and you have a much better total system. This controller can be programmed for any lithium battery. It is also an MPPT controller with Bluetooth. By the time you add in the cost of the cables, it will likely be slightly more expensive, but you can measure and order the exact length needed.
 
I have an 18ft trailer sailer.
I have 2 120hr leisure agm batteries, £90 from ebay. A 50w semi flexible solarpanel, £60 from ebay, and a small dual battery mppt controller from someone like bimble solar for around £40. That set up keeps me cruising for a week before having to charge up in a marina.

You would probably only need one battery, so around £250 would see you sorted.
 
I think the sophistication of the system depends on you. For my 21fter with 25w VHF and LED nav lights I have a box with 12x 18650 lithium cells. 4parallel lots of 3 cells in series. This give around 11.5 to 12 v. (about 8 AH claimed) It seems to last all season but that is because my actual usage is small. VHF mostly only used for transmission and nav light only used when coming home late. I could use a small solar panel for charging. I have used in the past a 5w panel attached with bungee over the main sail cover. Worked ok when I had Nicad battery no controller. However I seem to have left that home now with lithium. It is easy to remove the box and carry it home for recharge although not necessary so far.
So this is an extreme small case. Others have suggested lead aid batteries very heavy largish solar panels. Good if you have a space for them or it. Need a charge controller for any solar more than 10watts.
Now OP mentioned autopilot which will take power as will leaving VHF on receive for long periods and also nav lights on all night. So Op may decide he needs more capacity. I would not however get excited about a solar "kit" . Solar panel should be sized for what suits in the way of siting and controller if you need one should be MPPT fro a bit more money. Battery to suit from second hand old car battery to large Lead acid or lithium.
A pity to start off samll and find it inadequate but then you may find small is adequate for your actual usage. ol'will
 
Battery capacity is defined by Parkinson's Law

No matter the size of your battery bank your usage will grow, you will find more uses for the stored energy, until your usage (or the usage by your crew) is greater than the capacity.

Think big!

Large solar display, large battery bank, large inverter.

Once you have that large battery bank, etc, you, or the crew, will hanker after a small portable fridge and then......

Jonathan
 
Keep it simple.. as others have said all will depend on your usage.. I've got a Hurley 20 that is mostly used in the summer for day sailing a few days a week.. I have a 55Ah battery and a 5W solar panel, but the solar is small enough it doesn't really require a solar charge controller (using the 10% rule) and that keeps me charged all summer - that setup drives a VHF, tiller pilot, GPS, and occasional phone charge..
 
My advice is always to go for as much fixed solar power as you can fit. On our 24 footer, that was two 20w panels on the hatch garage; two because one or the other was likely to be shaded by the boom much of the time, and even a small amount of shade on a panel will seriously reduce its output. We had a PWM controller with dual output set up to charge the starter battery first, then the domestic battery, because dim lights are a minor issue, being unable to start the engine could be serious. It was enough to keep up with our modest needs at anchor in the summer, and would recharge everything during the week when working on the boat at weekends.

Battery power: Two batteries are the way to go, unless there are very good reasons for not doing so. A dedicated engine starter of modest capacity (lead acid), and as big a domestic battery bank as you can afford/have space for. When I did it, that was a 120AH LA leisure battery, but LiFePO prices have dropped a lot since then, so I don't know how the equation works out now. If you're thinking of racing, then the weight saving may well tip the balance in favour of Li. I'd wire things up so the alternator charges the starter battery, and have a voltage sensitive relay linking the batteries, so the domestic gets its share when the alternator is working.
 
scozzy said:
Why not just a bog standard leisure battery? approx 60AH and a 30£ solar trickle charger? If it's just weekend use then the trickle will keep I right during the week.
If you have an outboard you could charge up battery off that now and then to maintain capacity?
Click to expand...
You don't get much charge off an outboard.
When I was just sailing at weekends, l found a 20w panel kept the battery charged without other charging. I didn't have an auto pilot though.
 
Fantasie 19 said:
Keep it simple.. as others have said all will depend on your usage.. I've got a Hurley 20 that is mostly used in the summer for day sailing a few days a week.. I have a 55Ah battery and a 5W solar panel, but the solar is small enough it doesn't really require a solar charge controller (using the 10% rule) and that keeps me charged all summer - that setup drives a VHF, tiller pilot, GPS, and occasional phone charge..
Click to expand...
INteresting you can charge the battery without controller. I have a 25W foldable solar panel but with USB output.. not sure how I could connect that to a battery...
 
Mine's only 22', so less real estate for putting solar power, but I get by on a 20W panel, mppt controller and a 110Ah lead acid battery - same electrical kit as you. The tiller pilot is the hungriest item by far, trimming for a balanced helm rather than outright speed pays dividends.

I'm contemplating upgrading to Lifepo4 for weight and usable capacity - starting from scratch that's certainly the way I'd go.

I do have charging from the outboard, but it's frankly not worth the cost - very little power from it at rpm that I find acceptable, and I use the engine very little. A roaming solar panel on an outdoor socket would be a better investment.
 
In a small sailing cruiser (that at times I spent a month-plus aboard in summer) I used to remove the car battery from my Ford Anglia (the Harry Potter type - grandchildren won't believe I actually used to drive one) and take it aboard. It ran one small fluorescent tube masthead tricolour nav light and one small fluorescent tube interior light. The only other electrics on board were a couple of battery torches. Eventually I also added a Seafarer spinning-neon echo sounder that ran from a 9v dry battery. On return after a few weeks if the battery which I think was 40AH did not start the car I bump-started it, but it often did still start it. And my usual source of new car batteries was used ones from a scrap dealer with a 24 hour warranty.

Times have changed. I think only one marina existed within 200 sea miles of my home mooring.
 
I have a very similar situation to OP. Same sized boat.

105Ah battery with charging from a. Outboard. b. 10W solar c. 240v battery charger for when mains available.

Serves autopilot,Led lights, and very occasional VHF. Also separate battery monitor with usb connections.

Small solar keeps it toppped up when left on mooring, quite happily.
 
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