Simple top up solar panel for when I'm away?

Captain Crisp

Captain Crisp

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Hi,
can anyone recommend a simple top up solar panel for when I leave the boat on the mooring for up to 2 weeks at a time?
I have 2 80Ah leisure batteries.
I'm envisaging something I can whip out, fix to the carriage top roof, plug in and that will require the minimum of complex electrical hoohah...
Is that realistic?
Thanks!
Crisp
 
Yes it is.

But the usual trickle panels you see on ebay are often too weak ... and they rarely reach enough to overcome the batterys resistance.

Going too high in wattage of course will mean regulator ... so its a compromise of low wattage and slow charging with no need for a regulator.

I have a 5W panel that keeps my 7A/hr SLA well topped up - but I would never consider it for a larger flooded lead acid .... I would be looking at a 10W panel and I would be thinking to keep panel / batterys as separate setups ... meaning two panels ... croc clipped direct to each battery.

Try to keep leads short as possible as well - to avoid voltage drop as far as possible.

I dare say you will be inundated with advice now to fit xx panel and xy controller etc. etc. ...

Me ? KISS
 
I have a plain Kyocera 20W solar panel. Comes with a 3 (poss 5) year warranty.

kyocera solar panel | eBay

If you put it flat on the deck, or vertical, it will grab enough watts to keep your battery in tip top condition and not overcharge it. Connect each wire to the appropriate battery terminal, but you will need a blade fuse on the pos charging wire as near to the battery as you can.

No need to angle it for ALT or AZ.
 
Captain Crisp said:
Hi,
can anyone recommend a simple top up solar panel for when I leave the boat on the mooring for up to 2 weeks at a time?
I have 2 80Ah leisure batteries.
I'm envisaging something I can whip out, fix to the carriage top roof, plug in and that will require the minimum of complex electrical hoohah...
Is that realistic?
Thanks!
Crisp
Click to expand...
I have a 5 watt panel which keeps my 70 Ah battery topped up but it is permanently fixed and connected............ that saves messing about rigging , securing and connecting a panel every time I leave the boat. Mounted on the sloping cabin front
Picture even found its way onto Spectra Solar's brochure

1628860682595.png
 
Its actually nice to see that a 5W panel works ... the one I had in UK to keep my Suzuki 4x4 alive while standing - didn't ...

I still have the panel and metering shows output ... but a 50A/hr battery was too much for it.

But nice to see there are working panels ..
 
A permanently connected 5w panel won't keep a 50Ah battery with no load alive?
I stuggle to see how that can be possible unless the battery's on death's door.

A healthy battery should maintain charge for 6 months at least without help anyway, let alone merely two!

Unless they're connected to bilge pumps or summat that we've not been told about? In which case 10W would probably be ample - but I suppose that would depend on the leakiness of the boat.
 
Captain Crisp said:
Hi,
can anyone recommend a simple top up solar panel for when I leave the boat on the mooring for up to 2 weeks at a time?
I have 2 80Ah leisure batteries.
I'm envisaging something I can whip out, fix to the carriage top roof, plug in and that will require the minimum of complex electrical hoohah...
Is that realistic?
Thanks!
Crisp
Click to expand...


I have one of these:

Nasa Solar Panels | Force 4 Chandlery

Attached direct to an 110 ah battery. Probably not the cheapest or best but it's ok, I like it.
If the battery is well charged and the weather hot and I am leaving it some time, I cover it. With 160 ah you would be fine to leave it totally.

I have attached it to a modified camera tripod head and it can be angled. It's so small it does not get in the way at all on the pushpit. Having it permanently there is very handy and saves plugging in and storage below decks.

.
 
I've put 20w semi flex panels on three of my boat's ranging in size from 17' to 28'. They're permanently connected and charging through a regulator to avoid overcharging. I use cheap PWM charge regulators that cost about a tenner (they're very simple) and work well. Fit and forget - the regulators have a rudimentary display indicating charging status and state of charge.
 
Slowboat35 said:
A permanently connected 5w panel won't keep a 50Ah battery with no load alive?
I stuggle to see how that can be possible unless the battery's on death's door.
Click to expand...

I do not post just for sake of it ... my Suzi 4x4 sat on Hayling Island while I worked / lived away ... 2 - 3x a year I would return to UK and go to my Suzi ... battery was not maintained by that 5W panel. I would borrow a charger and get battery up again ...
That battery was still with that car later when sold on ... performing fine ....

[/QUOTE]
 
Then you aren't the only one!
I say again, any battery in good health will retain its charge for well over 6 months if there is no drain.
That probably means isolating it which I'd guess you didn't do with your car. (alarm fitted by any chance?)
I left my boat in Turkey from sept to may every year for ten years and every time the battery was fine.

A 5W panel can deliver nearly half an amp! No idle battery drains at that rate or anything remotely like it, so if the panel doesn't cope with trickle charging at 250ma on a daily basis then there is an unexpected drain from somewhere. There must be!
 
I have 2x lensun 20w and 2 controllers charging a 130ah battery each. Is that enough they seem to be charged when I get back to the boat after a week or few days.
 
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