Solar charger

[Bloggsy]

Thinking about mounting a solar panel on the boat cover (carport) roof to keep by twin batteries charged. Has anyone done this and what amperage output would I need to be able to leave the set up connected for long periods as a trickle charge but not damage the batteries?

Thanks

[xerotao]

Depends what batteries you have and their max charging input.

a good starting point would be a 20a or 25a mppt charger.

but if you just want to trickle charge. Low amp solar controller will be fine

[tryhard]

Agree with xerotao above.

You can get a 20 amp panel from most boating suppliers / 4wd outlets as well as a simple controller.

Easy to set up for top up charging.

You can use a cigarette lighter type connector to plug the battery to the controller for easy connect / disconnect.

Visit one of the outlets, if they have half decent knowledge, you should be able to walk out with a solution!

Will pm you some information that might help.

 

[frankS]

I used to have a very small solar charger on the roof of my half cab and it charged at about 700 miliamps or something like that very low charge and it had a diode so for overcharge or whatever, was only small but I never suffered with a flat battery. It was on all the time and I never had to connect or disconnect it.

Don't know if the solar charger helped OR if it was just a good battery that held it's charge well.

Frank

[noelm]

Be a damn good solar panel that can supply 20A.

[Pafisho08]

Jaycar Electronics can supply all the parts and  info you need . I have a system from them which trickle charges the boat battery from solar . 

Regds Bob

[xerotao]

2 hours ago, noelm said:

Be a damn good solar panel that can supply 20A.

You can have 100 "damn good" solar panels. but in the end of the day it depends how the sun is and which way the solar panels are facing.

But i was suggesting is that @Bloggsyshould get a solar charge controller to charge a flat battery or can go into float mode that will trickle charge a flat battery.

And solar does work. I run 2 fridges in my car 24/7 for the past 2 years and never had to charge my secondary battery. I just park my car in the sun on the weekend.

But what do i know? it was sugestion. not that your post added anything with helping @Bloggsys question.

[noelm]

OK, please yourself, no offence meant, just stating simple facts, a "trickle charge" is what he asked about, and a solar panel (singular) on his carport, 20A out of a carport covered in solar panels is still pretty good going.

[tryhard]

6 hours ago, noelm said:

Be a damn good solar panel that can supply 20A.

You are right....Whoops....should read "20 watt" 

[JonD]

If you want a quality product with a built in solar regulator, then have a look at some of the smaller solbian solar panels. The 23w is popular for the application you are wanting to setup but these being so popular are often sold out. 
I have solar panels on three of our vehicle running fridge freezer 7 days per week, even during weeks of rain the renogy fixed solar panels keep the lithium batteries fully charged each day. 
For my boat I have a 160w evacool solar blanket which puts out over 8 amps, which is enough to keep my batteries fully charged, including the Minn Kota battery. I use a 15 amp Victron solar regulator with the blanket. 

The renogy 175w put out just over 13 amps.

Edited November 4, 2022 by JonD

[Renegade460]

Easy and cheap way is to buy a 10W panel for each battery, no regulator required just plug in and forget.

[JustJames]

Is a charger really necessary?  The last 2 years my boat has been  unused from. Mid May to October and batteries have had plenty charge after winter hibernation.

 

Glass hull, twin batteries and 60hp 2 stroke in case any of that is relevant. 

 

 

[TheCount]

I know I'm late to the topic.

I've been running 3 x 100W panels to individual 2 x 10A MPPT and a 1 x 20A MPPT chargers to the 3 sets of batteries for 5 years - starter, accessories and a pair for the Motorguide electric (cable between them disconnected to bring them back to 12V). Volt meters on all.

Use the thickest cable you can get to minimise the voltage loss - but that does depend on the distance between the panels, chargers and batteries.. I work for an audio company so thick speaker cable is in my system - but I also ran it through conduit all through the roof cavity..

Not one of the batteries has failed (so far) and every month I disconnect the charging cables to give them all a rest.

Neutrik 30A connectors are used for easy connection. The females are setup in a stainless panel and male ends from the chargers.

Dealing with power - don't go cheap.

TC.

[dunc333]

ive never seen those connectors where can you get them cheers dunc333

[JimT]

for efficiency/free power use MPPT DC/DC Charger with solar input

depending on how fancy and space you have you could also have panel on boat so that battery/ies are topped up when out and not motoring along- would run 12V fridge/freezer as well.

2ndly have trailer connected to vehicle electrics while towing, choices/choices

Jim

Edited December 26, 2022 by jot

[TheCount]

On 12/27/2022 at 10:09 AM, dunc333 said:

ive never seen those connectors where can you get them cheers dunc333

"Audio" retailer/wholesalers like RS Components (https://au.rs-online.com/web/) or Amber Technology (www.ambertech.com.au - wholesale only, but they will recommend a retailer in your area) to name a few. I think Jaycar has a limited range too.

As a guide, each piece is around $10 wholesale..

TC.

[slothparade]

ive setup a solar system in my car, guess it should be applicable for you. 

i used redarc dcdc charger and a smart isolator for my dual batteries, the dc to dc manages it all and the isolator isolates the batteries. the charger distrobutes the charge to the battery with the lowest charge, been working really well. i also used anderson plugs for everything as ive standardised on them, the dc to dc i think can handle up to 3 batteries though i rarely use 3 and the 3rd is used as a fridge backup 

[XD351]

I would guess the OP is using lead acid batteries and from Jaycar you can get a 10w panel for under $50  CAT.NO:ZM9051

A pwm controller for under $20  CAT.NO:  MP3762

This would be fine for trickle charging .

You don’t need MPPT for lead acid batteries but for lithium you do .

Depends on how much they want to spend .