>>3 Battery PONTOON BOAT - Trickle / maintenance ‘SOLAR charging kit’ setup help!!!

[Leonvilj]

Hi all - I am new to the site and forum … I need some what I believe is simple help and recommendation!

I have a 2020 23ft Godfrey pontoon boat, Wilth a Honda VTEC 250 outboard. it came with 1 basic marine battery, (running all power, stereo, motor etc) which I removed and replaced now with 3 new Blue Top optima batteries. (pics below)
We boat in Arizona eight or nine months a year & primarily went with 3 of these AGM batteries so we could run the stereo for hours on the water.
I also added NOCO GENESIS 3 bank 15A (5A per charger) onboard charger, connecting all 3 batteries. after getting off the lake at the end of the day and plugging this in, it usually has them up to 100% within a matter of minutes.
so essentially, it’s just a trickle charger keeping the batteries topped off.

Last season I have had power to plug it into to keep the batteries topped off. I would imagine they never drop below 10 or 15%. ( as again the onboard charger would have them up to 100% usually within a few minutes.)

I am in a predicament now storing the boat, and there is no power for the NOCO onboard charger to plug into

1. have started looking at some solar kits, with either a 100 W panel or possibly 2 of those for 200 W( again this is not a use application of charging the batteries from being very low all the way up… I would imagine it’s just gonna top them up 10 or 15% to hit 100% charge)
2. it seems also i’m needing a charge controller… although I’m not sure size, etc. and
3. then i’m not certain but I am wanting to confirm if that charge controller needs to be connected to an additional good capacity battery? And if so, what size etc.
and then
4. Then I imagine from that battery and essentially want to confirm if I would need an inverter and if an inverter would work so that I can plug-in. AC plug from the onboard 3 battery NOCO charger ? if so size inverter. ?
** basically would ‘Solar panel - Charge controller - battery - inverter’ work??

The onboard charger regulates under charging and overcharging when plugged directly into the wall so I assume it would still do the same with an inverter!?


appreciate anyone with specific recommendations and products- looking to do as low-cost as possible as again this is not a primary charging unit!
cheers Leon

 

[seneysolar]

100w is plenty as a trickle charge for storage. Depending on the panel specs, a victron 75/10 would be fine, direct to battery, no inverter needed.

If all 3 batteries are parallel, you only need 1 charger.

 

[Leonvilj]

apologies, not sure I understand. ( got you in the 110w panel)

so the 3 batteries are all in waterproof boxes, sealed with all positive and negatives connecting to the onboard. NOCO CHARGER… which unless I open all the batteries and cases up…. has just the standard 6 foot cord with the AC plug to plug in the wall and / or inverter..

i’m not quite following your configuration, unless you’re implying connecting the Victron directly to one of the 3 batteries on board. ??
this would be kind of an inconvenience and hassle every time as I would have to access 1 of the 3 batteries, which are not in the most convenient places, and take apart the waterproof case to get to the positive and negative..
thanks again for your thoughts here

 

[seneysolar]

Having batteries parallel would have all the neg hooked together and all the pos hook together as 1 big battery.

This way your capacity increases but not voltage.

 

[Leonvilj]

got it, so a lot less expensive just to get a 100w or 220w panel, and probably a 75/10 and directly connect that charge controller to probably the middle battery negative and positive terminal posts?

One other thing, I also have a Perko switch…
which allows me to have it on number 1 position, which just runs the motor off that 1 battery,
position number 2. which the stereo ties into those other 2 batteries
and
position ‘All’ - which is all three batteries live.
does this make a difference on which battery I connect the control charger to? Or would I just connect to any battery and make sure it’s on the all position? Or off position?

 

[Bop]

With charging multiple paralleled batteries- it is best to have the positive charging lead at one end of the string, and the negative charging lead at the other end of the string ie the positive goes on the left hand battery positive in your diagram and the negative on the right hand battery negative...
(this applies to ALL your cables btw, both charging and to the loads...)

This equalises the voltages across all the batteries and charges all equally (as each lead has a small but measurable resistance)

Your 'center battery' connection is the next best (but could leave both the left and right batteries slightly undercharged in relation to the center battery) and 'end feeding' the parallel batteries is the worst option...

Say you hooked everything to the left battery (loads and charging circuits) with each lead having 'X' ohms resistance- the middle battery has resistance in both its leads 2x X ohms to the left battery, so gets a slightly lower voltage (and charge level) and the right battery is ever worse- it has 4x X ohms of resistance from the charge source, dropping its charge voltage even more...

Where the 'cross bank connection' I described has the positive connected directly to the left battery, but has 2x X ohms in its negative lead, the center battery has 1x X ohms in its positive lead and 1x X ohms in its negative lead ie 2x X ohms again, and the right battery has 2x X ohms in its positive lead, but is connected directly to the charge source on its negative post so again 2x X ohms total resistance...
Thus all the batteries get the exact same voltage fed to them...

The same applies to loads as well, but in reverse- If your loads are connected to one end battery (again say the left), it will supply the most current and be depleted more quickly, the center battery has 2x X ohms and will supply less current, and the right, far end battery has 4x X ohms so provides the least current...
This means that the left battery will be working harder and have to be replaced earlier than the other two...

It also means your battery bank will actually have less stored power than the cross connected bank- despite being the same batteries!!!- this is because you will actually have circulating currents inside the bank...- an ammeter on the load output lead will show zero- but as the left battery is depleted more during the load, when the load is turned off, it is now at a slightly lower voltage than the other two- now current will flow from them to the left battery until they 'charge it up'' to their voltage- and as the chemical reaction has losses in both discharging and charging, you have just lost a bit of your stored capacity as heat inside the battery bank as it equalised...

 

[Bop]

got it, so a lot less expensive just to get a 100w or 220w panel, and probably a 75/10 and directly connect that charge controller to probably the middle battery negative and positive terminal posts?

One other thing, I also have a Perko switch…
which allows me to have it on number 1 position, which just runs the motor off that 1 battery,
position number 2. which the stereo ties into those other 2 batteries
and
position ‘All’ - which is all three batteries live.
does this make a difference on which battery I connect the control charger to? Or would I just connect to any battery and make sure it’s on the all position? Or off position?

This complicates it a bit more- you need to 'cross feed' the two paralleled batteries, and remember to always leave the switch in the 'all' position- anything else will involve adding more bits to allow charging all the batteries...

 

[Leonvilj]

this is great information. It makes a lot of sense. Thank you for this.

 

[Leonvilj]

good morning, so in visiting my boat in storage this morning… The logistics of the battery layout is going to be extremely challenging! ( for a simple, solar panel and charge controller to tie end of the system )

I have 2 batteries they installed in waterproof boxes under the backseat
on the right rear side of the boat,

then the 3rd battery is by itself under the backseat clear across on the left side of the boat! easily 8 to 10 feet away from the two batteries on the left and it looks like they ran wires underneath the boat… A lot of complexity.

all wires from all three batteries eventually do connect into the onboard NOCO Charger, which again has been great and simple. Just simply plugging in the AC plug from the onboard charger to the wall when I’ve had power available.

i’m thinking as I’m going to be the one to do this with very basic electrical acumen, I’m probably going to have to go the route with the solar panel- charge controller- battery - inverter ( if anyone can confirm that this works.. not sure why it wouldn’t) so I can just plug my onboard charger AC into an inverter
again, just for basic trickle charge and topping off the batteries as they never really dropped much at all.

can anyone share the products recommended least expensive route…i’ll get the Victron 75/15 .. a good 200 w panel…
I just need some advice on what external battery would work to tie into the solar panel and Victron… And then what would be a sufficient inverter to connect to that battery?

thank you so much for all in any help!
cheers Leon

 

[Bop]

I take it the existing mains charger can charge all three batteries then- if so, it sounds like the best bet is simply attaching the solar charge controllers output leads in parallel with the existing mains chargers output leads and be done with it...
(it's not the 'perfect setup' but it will work... and anything else sounds like a nightmare to do...)

You can safely do this without any issues with either the charge controller or the mains one- either or both can be running at the same time and that way you don't have to leave the inverter running...

Connecting to the batteries is preferred obviously, but that sounds like a nightmare to do in practice...

It would be easier just to tap into the existing chargers cabling (assuming it is heavy enough- what is the mains charger output current rating?)
ie remove/cut the output leads from the mains charger (near but not AT the charger if they need to be cut)- obviously all power is turned off at this point, both battery and mains, fit to a 'doubling block' ie a pair of 3 way joiners and fit two new sets of leads to that- one set of the new wires goes back to the mains chargers outputs and one set to the solar charge controllers outputs... (if you had to cut the main chargers output leads, then just fit them back into the two 3 way couplers and use a single set of leads to the solar controllers outputs)
Once this is all done and checked for errors (all positives in one 3 way connector, all negatives in the other!!!), turn the battery power back on and finally connect the panels up to the charge controller...

The Victrons are fairly tolerant of having the panels connected with no batteries, but it really isn't advised- I would suggest routing the panels cables past the battery master switch and putting a switch in the panels power cable (it really doesn't matter which one, positive lead is 'the norm' but electrically it isn't an issue) and make it a practice to turn the panels switch OFF before turning the master battery switch to off, and turn the master battery switch on before turning the panels on... ie the panels should never be turned on without the batteries being on...
Like I said, the Victrons are quite tolerant of this, but still, you don't want to risk damaging the controller for the sake of a simple switch...

 

[Rocketman]

Just another idea - instead of one 200w panel and one solar charge controller get two 100w panels and two solar charge controllers. (50w panels would work as well).

One charge controller wired to starter battery (permanent) - be sure to fuse it at the battery…
One wired to the “stereo” batteries (permanent) - also fuse at the battery.

Then make the solar wires removable- maybe an Anderson connector or any 12v connector.

Mount the permanent stuff out of the way - once. Then add or remove the panels easily.

I would use the Victron Smart mppt’s 75/10 or 75/15 so you have Bluetooth access to see the history of the charger (for the last 30 days). Plus you can see battery voltage when within 15 feet.

Good Luck

Ps - bonus use- take the solar out on the lake and extend the tunes running time.. Who doesn’t need more tunes running time?

 

[Leonvilj]

good info and ideas. thanks for that

 

[Supervstech]

Do you have pics to share?
Of the boat, and the wiring of the batteries?
We can lilwly extend your time on the tunes by getting the batteries arranged and wired optimally for use, and charging.

Lets see what you have!

 

[Leonvilj]

Do you have pics to share?
Of the boat, and the wiring of the batteries?
We can lilwly extend your time on the tunes by getting the batteries arranged and wired optimally for use, and charging.

Lets see what you have!

we just got back to California and the boat in Arizona so we won’t be back out there for three or four weeks unfortunately.

but my plan is to take some video of the batteries I’m wearing once we get back out there

 

[SparkyGage]

I'm curious of the logistics:
1. Do you not have a master cut off switch that completely disconnects the batteries from the engine and fuse panel when stored?
2. Where are you planning to mount panels - on the boat or on a storage shed?

 

[Bop]

I'm curious of the logistics:
1. Do you not have a master cut off switch that completely disconnects the batteries from the engine and fuse panel when stored?
2. Where are you planning to mount panels - on the boat or on a storage shed?

It is quite common for boats permanently in the water to not have their batteries cut off entirely as you want some things powered up (like bilge pumps and the like)- indeed a 'friend of a friend' lost his own boat that way (sunk but later retrieved, but repairs cost tens of thousands) as his battery bank went flat and had no solar on the boat (and was at a mooring, not at a dock, so no shore power)
It went years with no issues, no leaks- until there was a leak (the deck had a small rust hole develop out of sight, where water pooled when it rained against the engine hatch), they had a lot of rain and the water was being channeled straight into the engine room, which filled up enough after the battery went flat running the bilge pump that waves started coming over the sides and filling it even more and around it went, until down it went...

Other boat owners nearby were helpless to stop it by the time it was noticed, as it was securely locked, and by the time someone had found tools to 'break in' to a steel hulled boat with locked steel hatches- it was too late and it was playing at being a submarine...

Even things like propeller shafts in inboards can have a slow but constant 'leak', not enough to worry about normally, but given sufficent time, adds water to the bilges

 

[SparkyGage]

It is quite common for boats permanently in the water to not have their batteries cut off entirely as you want some things powered up (like bilge pumps and the like)

I'm familiar with that (houseboats), but reading through I can't tell if he is keeping the boat in the water and loosing access to shore power or pulling it out an now power in the storage lot. We always stored our boats we pulled with the battery disconnected. Mainly looking for clarification before comment because how it's being stored would affect any suggestions.

(Do they make bilge pumps for pontoons now? )

 

[Bop]

(Do they make bilge pumps for pontoons now? )

Very much so, apart from tiny 'inflatable' pontoon flatdecks, pontoon hulls are a hull just like any other, subject to possible leaks from above and below the waterline...
;-)

 

[Leonvilj]

The boat is going to be kept and is kept in a 40 foot storage unit and a storage facility…
it has a ‘Perko’ switch which twin turned to the opposition, completely disconnects all power from the three batteries for anything.

The switch has ‘OFF’ ‘Position 1’ ( main starter battery ) ‘Position 2’ ( the other 2 batteries powering stereo) ‘ALL’ (all 3 batteries which I have it on when on the water and moving. ‘position 2’ when in. a cove or beach at the lake listening to music.

 

[Leonvilj]

also does anyone know if I would need 10 AWG wire of 12 AWG from solar panel to Charge controller ? (which I’m going to mount two of those in the pontoon- connecting one to the single battery, and the other to the two batteries powering the stereo) and 10 or 12 AWG then from the charge controller to the battery tops?