We are thinking about a portable panel to supplement the fairly meagre charging capabilities of Flamingo's "vintage" alternator.

Ideally this would be able to sit on the roof of the back cabin / engine room, though the large number of roof obstructions might make this difficult.  Alternatively it could be on the roof of the main accomodation cabin, though cabling could then be more of a challenge.

 

What experience do people have of these please?  Are they easily damaged?  How can you stop them taking off in the wind?

 

Any specific recommentations for brands or suppliers, please?  Any brands to specically avoid?

Do you have ones with an integral controller, or is it better to use a separate one?

Thanks.

2 hours ago, alan_fincher said:

supplement the fairly meagre charging capabilities of Flamingo's "vintage" alternator.

That's a reasonable thing to want, but without some numbers (what it puts out, how long it runs, what your more generous energy budget looks like, how much you hoped to spend) then we're guessing. Which may also be a reasonable thing to do. 🙂

 

I have no experience of the very portable folding panels - the price of them puts me off. I think you're being asked to pay a lot for a tidy presentation, which may be great for backpacking but not boating.

 

I used to have a pair of ~30W panels in the flexible panel style which were nice to put in the car windscreen when it sat idle for weeks,or if I sat out in the countryside to do some computering, but I accidentally killed them. I find there's nothing at a sensible price.

 

What I've found sufficiently portable for a narrowboat is an Eco-Worthy 130W, or similar 100W,

https://www.amazon.co.uk/ECO-WORTHY-Flexible-Waterproof-Photovoltaic-Caravans/dp/B0DM1LV67Q (has been down to £115/pair ~ 2.2W/£ )

https://www.amazon.co.uk/Flexible-Monocrystalline-Off-Grid-Portable-Charging/dp/B0CRVF9JJT (currently at 1.6W/£) 

 

mounted on four 'taxi magnets' with sufficient washers and the Nyloc M6 they come with. Possibly the tip was from @Jen-in-Wellies? (Thank you, whoever)

https://www.ebay.co.uk/itm/184151507132 (10 pack/£32, but maybe £5/ea elsewhere)

They are strong enough to be pinch hazards in themselves, and lifting a flexible panel with one on each corner feels like trying to get an octopus to let go of a tasty fish! I can imagine people I have known (the ones who ask me to open jars) not having the hand strength to lift one of these off 4mm steel.

 

These have withstood 40mph gusty winds. Above that I would want to be around and ready to rescue them or lash them down, but I suspect they will go higher.

 

A rigid panel can be put on magnetic mounts, but I think they're bulkier and further away from what you're asking for.

There are some options collected on https://floydtilla.co.uk/2023/03/25/planning-for-solar-panels-part-2-panel-mounting-options/ , thank you @David Floyd.

 

 

The panels advertised as "12V" are usually more like 18~21V at maximum power and 25V open circuit. It's not efficient, or long term safe, to connect them directly to the battery, so you also need a charge controller. The ones that tend to come bundled with a panel are likely to be junk.

 

There is as much to choose from here as in panels...

 

 

2 hours ago, alan_fincher said:

Ideally this would be able to sit on the roof of the back cabin / engine room, though the large number of roof obstructions might make this difficult.  Alternatively it could be on the roof of the main accomodation cabin, though cabling could then be more of a challenge.

 

Since you're reducing the voltage (~21V in, 13V out) then it's sensible to have the charger controller closer to the batteries if you can, and essential if you want >5A delivered.

 

However if you have a high current provision e.g. for a 12V fridge, then it can go the other way. I extended mine to feed the laptop and have occasionally shoved solar back down the same cable.

 

Mushroom vents are handy for temporary cable access, if you don't mind how it looks.

7 minutes ago, wakey_wake said:

mounted on four 'taxi magnets' with sufficient washers and the Nyloc M6 they come with. Possibly the tip was from @Jen-in-Wellies? (Thank you, whoever)

Not me. Can't remember who either!

@wakey_wake

Many thanks for your time to give a detailed answer.

A lot to digest there, and I've been away for last two days, but I should be able to go through it tomorrow.

Some facts:

Boat is historic ex working boat with usual engine room and back cabin.
However cabin conversion over the hold only starts a couple of feet forward of engine room so is not connected to it.
Engine: Lister HA2 (22HP @ 1,800 rpm)
Alternator: Very old Lucas ACR, believed to be a 60 amp unit.
Engine is slow revving, and pulley ratios not great, so alternator probably often spinning at less than ideal speed.
12V system
Domestic batteries: 5 * 110A Lead Acid.  (Condition probably not that great).
All batteries are in the engine room.

We have had some success in the past with a borrowed 100W panel (not a portable one) and a very basic charge controller.  Although I still have that controller I would prefer to upgrade to an MPPT one if possible. (I'm not sure I see a portable panel having a charge controller inbuilt as a good thing ?).

 

1 hour ago, alan_fincher said:

Many thanks for your time to give a detailed answer.

You're welcome. And yet I forgot a really important point - in which months do you need the extra juice?

Alan, on Norway we didn't want to have solar panels attached, but wanted an option for charging without running the engine so have opted for a Renogy Solar blanket, 

200W/400W Solar Panel Blanket | Renogy UK

it neatly folds away, we got the 400w one which in honesty is probably a bit big to fit on the cabin top but the 200w one should do. the reason we opted for the 400 is so we can tie it to the top plank and drape down the sides if the weather permits. we made an extension lead for it and have a discreet Andersen connecter wired to the solar controller.

 

11 hours ago, wakey_wake said:

You're welcome. And yet I forgot a really important point - in which months do you need the extra juice?

At the moment we are unlikely to do much boating other than in late spring to early autumn

5 minutes ago, stagedamager said:

Alan, on Norway we didn't want to have solar panels attached, but wanted an option for charging without running the engine so have opted for a Renogy Solar blanket, 

200W/400W Solar Panel Blanket | Renogy UK

it neatly folds away, we got the 400w one which in honesty is probably a bit big to fit on the cabin top but the 200w one should do. the reason we opted for the 400 is so we can tie it to the top plank and drape down the sides if the weather permits. we made an extension lead for it and have a discreet Andersen connecter wired to the solar controller.

 

Thanks - that is useful info, and I have already seen that one.

 

I assume you are happy with them?

yes absolutely. first trip in a few weeks so it'll be good to see it in a practical setting rather than in the yard!

3 hours ago, stagedamager said:

[ we ] have opted for a Renogy Solar blanket, 

200W/400W Solar Panel Blanket | Renogy UK

It's a nice form factor. For folks who only want a little lift, 1.2 ~ 1.4 W/£ may be perfectly acceptable.

I'm looking more at paving the whole thing... wish the PVs could serve as paintwork protection!

 

2 hours ago, alan_fincher said:

At the moment we are unlikely to do much boating other than in late spring to early autumn

Lacking numbers, I guess yield should be adequate at least on some days.

You might pair it with a Bluetti / Ecoflow box to average out the days, which avoids evades? circumvents? having to rewire the boat and meet BSS standards on installed kit.

 

Wind may be more of a problem and the blanket format could be a weakness there?

Edited May 4May 4 by wakey_wake
avoids...?

20 hours ago, alan_fincher said:

Alternator: Very old Lucas ACR, believed to be a 60 amp unit.
Engine is slow revving, and pulley ratios not great, so alternator probably often spinning at less than ideal speed.
12V system

 

Why not get a proper alternator and a big enough pulley?

 

As you know, I have a Kelvin K2 running at 250-300rpm cruising speed and it charges up my batteries just fine! Including the LFP.

 

 

 

 

 

 

20 hours ago, alan_fincher said:

Alternator: Very old Lucas ACR, believed to be a 60 amp unit.

 

I was unaware that ACRs went as high as 60 amps. I thought 45 amps was the largest and some were around 30 amps. An A127 were often sold as 60 amp machines, but they did not have the big plastic cover over the back.

 

1 hour ago, Tony Brooks said:

 

I was unaware that ACRs went as high as 60 amps. I thought 45 amps was the largest and some were around 30 amps. An A127 were often sold as 60 amp machines, but they did not have the big plastic cover over the back.

 

You've got me thinking now Tony.

Possibly I mean AC5 rather tham ACR

I'm not where either the paperwork or the actual device are, so can't  check at the moment.

1 hour ago, MtB said:

 

Why not get a proper alternator and a big enough pulley?

 

As you know, I have a Kelvin K2 running at 250-300rpm cruising speed and it charges up my batteries just fine! Including the LFP.

I'm  no expert but for a similar  engine in Sickle I was told I could only have a large pulley if the overhead hand start was removed, (which it was). I regretted losing the hand start, and don't want to lose the facility on Flamingo

 

11 minutes ago, alan_fincher said:

Possibly I mean AC5 rather tham ACR

 

That is more likely on a vintage engine, a CAV commercial vehicle (and MOD) alternator, with remote regulator with, I think, a wander fly lead to select low, normal, or high charging voltage. Not one I would be in a hurry to change.