new to board

[jravenstine]

I just bought used electric pontoon boat. It has 8 6 volt deep cycle batteries running it. I will probably use about every t weeks for a few hours. I bought a 85 watt solar panel and live in southern california so get lots of sun. I have solar panel plugged into controller which is plugged into a 12 volt battery. I then have an inverter pluged into system and then have battery bank that is on a timed charger plugged into the inverter that is getting energy from solar panel. Is this enough to charge boat? Will the inverter even have enough power to make charger work? Thanks

[zap]

You haven't provided anywhere near enough information for your questions to be answered.

How are the 8-6v batteries wired? 12v, 24v, 36v, etc. ?  What is the capacity in amp hours?
What's the specs on the motor?  12v, 24v, 36v, etc. ?  And how many watts or amps is it rated for and how much power does it use under normal operation?

I'm no expert but those on this board that are will need that info before they can offer much assistance.

[FishbonzWV]

I'll go out on a limb here and guess you have a 48v main battery bank.
So, using that assumption, here's a list of losses in your system.
Solar panel to controller to 12v battery...loss of watts
12v battery to inverter...loss of more watts
inverter to charger...loss of even more watts
My suggestion is to add 3 more 85w PV's in series to your system and charge the main bank straight up.
Bonz

[wooferhound]

Sounds like you are charging 2 battery banks
a 12 volt bank with a charge controller
and another "Higher Voltage?" bank
you say you are charging the 12 volt battery and powering the inverter directly from the panel

Your 12 volt system will work fine
but your inverter will not run straight off of the panel by itself

[ghurd]

Nowhere near enough info.

Guessing it is golf cart batteries set up for 48V,
and something like an Etek, or big brushed PM motor.

It will not work enough to do any good.
Could get a bit of trickle charging from the proposed system, but that's about it.

It will require some fancier circuitry to protect the 12V battery from excessive discharge, or the 12V battery will be ruined in short order.

"Will the inverter even have enough power to make charger work?"
For all we know, it is a 50A forklift charger plugged into a 60W pocket inverter.


At the minimum, it needs 4 exactly matching 12V panels (get 3 more of the same one you have) and a decent 48V controller like the MorningStar TriStar TS-45.

Doing it half way will result in first ruining the 12V battery and 48V bank,
then buying the right solar equipment, and new batteries.

I would suggest considering a second smaller system in 12V.  A pair of 6V golf cart batteries, a 50~75W class panel, and controller?
It would be handy for the lights, stereo, sonar, Ship to Shore, GPS...
G-

[Rover]

I'd actually be interested in a few things about the boat itself, brand name? , home built?, length, draft, type of pontoons , how long does it normally run on a charge? approximate speed over water, motor name? if no name info on panel, if no panel then (approximate dimensions).

Or is this a retroffited pontoon boat with a cpl of Minn Kotas on it.. (still interesting).

Agree with all the others, unless this is a bath tub boat with real small 6 volt nicads , the one panel you mention wil not be enough

[jravenstine]

Re: new to board
« Reply #2 on: June 16, 2010, 04:17:47 AM »
   Reply with quote
I'll go out on a limb here and guess you have a 48v main battery bank.
So, using that assumption, here's a list of losses in your system.
Solar panel to controller to 12v battery...loss of watts
12v battery to inverter...loss of more watts
inverter to charger...loss of even more watts
My suggestion is to add 3 more 85w PV's in series to your system and charge the main bank straight up.
Bonz

Hi bonz,

Sorry it took so long to get back to you. I forgot the website address that I posted on. I finally found it. Yes the battery bank is 48 volts connected to 48 volt electric ray  motor. I think each battery puts out 125 amp hours. I have access to 3 more 45 watt solar panels and I could wire them to 48 volt and connect directly to battery bank to charge. Since I do not use more than 4 hours 3 or 4 times a month do you think this would charge my system? By the way I am no longer using 12 volt battery and inverter. I think the 85 watt panel with 45 to 50 watt panels is the max I can fit on boat. Will this be enough to charge? Also what charge controller should I get. Also how large of wire should I use?  Thanks again

[jravenstine]

Nowhere near enough info.

Guessing it is golf cart batteries set up for 48V,
and something like an Etek, or big brushed PM motor.

It will not work enough to do any good.
Could get a bit of trickle charging from the proposed system, but that's about it.

It will require some fancier circuitry to protect the 12V battery from excessive discharge, or the 12V battery will be ruined in short order.

"Will the inverter even have enough power to make charger work?"
For all we know, it is a 50A forklift charger plugged into a 60W pocket inverter.



Sorry it took so long to get back to you. I forgot the website address that I posted on. I finally found it. Yes the battery bank is 48 volts connected to 48 volt electric ray  motor. I think each battery puts out 125 amp hours. I have access to 3 more 45 watt solar panels and I could wire them to 48 volt and connect directly to battery bank to charge. Since I do not use more than 4 hours 3 or 4 times a month do you think this would charge my system? By the way I am no longer using 12 volt battery and inverter. I think the 85 watt panel with 45 to 50 watt panels is the max I can fit on boat. Will this be enough to charge? Also what charge controller should I get. Also how large of wire should I use?  Thanks again


At the minimum, it needs 4 exactly matching 12V panels (get 3 more of the same one you have) and a decent 48V controller like the MorningStar TriStar TS-45.

Doing it half way will result in first ruining the 12V battery and 48V bank,
then buying the right solar equipment, and new batteries.

I would suggest considering a second smaller system in 12V.  A pair of 6V golf cart batteries, a 50~75W class panel, and controller?
It would be handy for the lights, stereo, sonar, Ship to Shore, GPS...
G-

[FishbonzWV]

Ahoy J,

If you series the three 45's with the 85, the max current you will see is what the weakest 45 puts out.
So you are looking at around 4 amps @48v. This is still a trickle charge for that size bank.
The good news is you said you are in SoCal ,so, "it never rains in California".
I would run 10 AWG marine wire (but that's just me), you could get by with less.
Ghurd mentioned using a TriStar for the controller.
I assume that being on a boat, those are AGM batteries or at least sealed lead acids.
Set your controller up for the correct charging voltage.
Shore power for a good topping off would be nice.

[jravenstine]

Ahoy J,

If you series the three 45's with the 85, the max current you will see is what the weakest 45 puts out.
So you are looking at around 4 amps @48v. This is still a trickle charge for that size bank.
The good news is you said you are in SoCal ,so, "it never rains in California".
I would run 10 AWG marine wire (but that's just me), you could get by with less.
Ghurd mentioned using a TriStar for the controller.
I assume that being on a boat, those are AGM batteries or at least sealed lead acids.
Set your controller up for the correct charging voltage.
Shore power for a good topping off would be nice.

Thanks for the quick reply. I also talked to a guy today that has 2 24 volt 120 watt panels. The amps seem low though.
max power voltage is 35.20 v
max power current is 3.4 A
open circuit voltage is 43.4
short circuit current 3.66 A
poly/72
24vdc
solar x is brand model SX1000.
Which would be better the first way I said or this way. I am looking for more than just trickle charge. I am also going to check to see if I can fit 3 more 85 watt panels like I currently have. Space is limited.Thanks

[FishbonzWV]

Four 85's will give you more amps than the two 120's.
Panels in series add voltage not amperage.
If we are talking about total watts, just multiply the panel watts x number of panels.

[kurt]

i merged your 2 threads into one as the second one was a continuation of the first anyway and it is better not to spread a single discussion all over the board.

[ghurd]

If you were waiting for me to respond,
I was away... far far away... in a very nice place.
Sadly, I am back with a view of the defunct steel mills of Ohio.

The guys pretty much summed it all up.

I really do not believe the batteries are enough AH to work as well as you hope.
May want to consider going to at least 8 x 6V 210AH class golf cart batteries.  Math says about double the capacity, but real life will be more.
You may have 210AH class batteries?  120AH class 6V are sort of an unusual battery.

No need to get too many charging amps.
With 125AH or 220AH, it still will not take a whole lot to get them up to regulation voltage.
While 4 x 85W will give more amps, the batteries really can't absorb that much for long anyway, especially under the stated conditions of not a lot of use with long periods of charging.

The 2 x 24V 120W PVs are probably a pretty decent match.  If the price is right, that's a bonus!

Then can use the 85W on maybe a 85~115AH class 12V deep cycle battery for the 12V stuff.

Do Not use regular car parts store automotive grade wire.
The insulation absorbs water, which can lead to all kinds of issues in a 48V system.
The insulation is Not sunlight/UV resistant either, so it will not last as long as you hope.
G-