Rebuild of Electric Pontoon Boat

[Avalon14]

Hello solar gurus-

I have purchased a 2013 pontoon boat which was converted to electric. I believe the conversion was done around 2015 from what I can tell.
It has the following equipment:

• 5KW Parsun motor
• 4 x 12V deep cycle, lead acid batteries
• 120VAC x 48VDC charger

The trouble is, the wiring has all been disconnected and there is no documentation. I have positioned the batteries where the cables seem to want to fall (4/0 cable), and it seems like the batteries were wired in parallel. This has me a little mystified and more than a little hesitant to connect anything. All the cables go below deck which doesn't help.

Any input would be helpful. Where I might find wiring diagrams, etc.

Thanks!

 

[Bob B]

Hello solar gurus-

I have purchased a 2013 pontoon boat which was converted to electric. I believe the conversion was done around 2015 from what I can tell.
It has the following equipment:

• 5KW Parsun motor
• 4 x 12V deep cycle, lead acid batteries
• 120VAC x 48VDC charger

The trouble is, the wiring has all been disconnected and there is no documentation. I have positioned the batteries where the cables seem to want to fall (4/0 cable), and it seems like the batteries were wired in parallel. This has me a little mystified and more than a little hesitant to connect anything. All the cables go below deck which doesn't help.

Any input would be helpful. Where I might find wiring diagrams, etc.

Thanks!

If there are 4 12V batteries and a 48V charger ..... That indicates the batteries must have been wired in series.

Maybe some pictures of what things look like might give us a better idea how to land the wiring.

 

[Avalon14]

Thanks for your prompt response Bob!
Agreed, the 4 x 12V batteries and 48V charger output seems to indicate series wiring for sure, that's what's causing me heartburn. But I just can't make that work with what's there.
Not sure pics would be of any help since everything is just in there like I think the wires want to lay. Also, the batteries are scattered about the boat, for weight distribution I suppose, it's a rather small boat. 2 are at the stern in the middle, one is starboard and up a little bit from the stern, one is port and also up a little way.
Any further thoughts are appreciated. I'm totally happy to snap some pics if you thing that would help. I'll go ahead and post some tomorrow.
Mark

 

[MakeMePower]

turning batteries different directions can make the polarity in series look correct.

the 48v charger shows they were wired in series, looking at a parsun 6k unit, it also indicates 48v.

there is 99.9 chance i am right, and enough chance to blow the motor if I am wrong.

i strongly recommend you check every battery individually to see if they are healthy before connecting them in series.

 

[Avalon14]

Hey, where did you find info on the motor? I'm coming up empty!

I metered a couple of the wires to figure out where they go and I think I've got this figured out.
Looks like 48V to the motor and 12V to the other systems (audio, horn, remote control for the motor), I think that makes sense.

I'll post again if I run into trouble.

Mark

 

[MakeMePower]

Joy 6.0 Electric Outboard Motor | 9.9hp Boat Engine

Joy6.0 is another innovative electric outboard engine of PARSUN, featuring with direct-drive PMSM, quiet running, and zero emission, maintenance free.

www.parsunpower.com

Rated voltage

48V DC

 

[IGBT]

4/0 cable for a 5kw 48v motor? Overkill?

 

[MattMan119]

ABYC Wire Size Calculator

boathowto.com

I did almost the same … I moved from 3awg to 1/0

 

[Delmar]

Welcome to the Forum.

If the lead batteries have been laying around a while without being charged you can bet they are pretty much toast. Budget for a lithium replacement that will save weight and eliminate a major corrosion headache.

Don't use one battery to power the 12V accessories. Will throw the bank out of balance. Purchase a good 48V-12V converter.

Hopefully there is a little lead juice leftover for you to fully test the wiring. Learn with lead before getting an expensive lesson with lithium. Experience gained = equipment ruined.

Then add a solar panel canopy to extend your time on the water.

 

[Rednecktek]

Easy option might just be a pair of 48v LFP batteries, one port and one starboard. Panel canopy and a decent SCC should get you putting along nicely.

With the 48v -> 12v converter be aware that a 120w converter may well fry at 121w so plan to oversize it a bit for your largest load. If you have pumps or fridges or the like plan for startup surge.

Alternately, if you want a separated system, a stand alone 12v for that stuff and a small MPPT from the 48v bank to the 12v bank.

 

[Avalon14]

OK Gurus-
Here it is, as I intend to connect it. I see I neglected to label battery #1, it the left one in the picture with 2 batteries (IMG_4598).
The 12V accessories are to be wired with the small gage wire shown on the deck in IMG_4600.
The 48V charger will get hooked up in parallel w/ the Motor as shown in the sketch, the wires are not shown in the pics.

Let me know what you think!
Thanks,
Mark

 

[Bob B]

That diagram looks like it could very well be how things are currently wired ...... I would take the advice from others and use a 48 to 12V converter instead of tapping the 12V off of one battery.

 

[Avalon14]

Thanks everybody for the great advice!
Any suggestions on places to get a proper converter/MPPT such as Rednecktek suggests?
Recommended manufacturers?

 

[IGBT]

Thanks everybody for the great advice!
Any suggestions on places to get a proper converter/MPPT such as Rednecktek suggests?
Recommended manufacturers?

Victron Energy ORI481224110 Orion-TR 48/12-20 DC DC Converter

 

[Rednecktek]

I'm a fan of HQST, RichSolar, or Vevor. They'll all do the same job and be cheaper than $$Victron.

 

[Avalon14]

Thanks again Gurus!
Planning on lighting it off tomorrow and will add the MPPT soon.
BR

 

[Avalon14]

Update...
It works!
Thanks again all!

 

[Delmar]

Update...
It works!
Thanks again all!

Pictures or it never happened.

 

[Avalon14]

LOL. I'll try to remember to snap one next time I'm @ the marina.
I do have a question...
So with these 4, 12V, 98Ah batteries connected in series, what is the Ah rating of the whole bank?
98Ah is my intuition here, but I'd like some backup for that.
thx,
Mark

 

[MakeMePower]

LOL. I'll try to remember to snap one next time I'm @ the marina.
I do have a question...
So with these 4, 12V, 98Ah batteries connected in series, what is the Ah rating of the whole bank?
98Ah is my intuition here, but I'd like some backup for that.
thx,
Mark

its whatever a single battery Ah is (if they are all the same) it only goes up in parallel

 

[MattMan119]

LOL. I'll try to remember to snap one next time I'm @ the marina.
I do have a question...
So with these 4, 12V, 98Ah batteries connected in series, what is the Ah rating of the whole bank?
98Ah is my intuition here, but I'd like some backup for that.
thx,
Mark

4 in series for 48v makes it 98ah
4 in parallel for 12v makes in 98x4=392ah

 

[Avalon14]

Thanks MattMan!
BTW, is there a way to get email notified when I get a response here?

 

[Delmar]

So with these 4, 12V, 98Ah batteries connected in series, what is the Ah rating of the whole bank?
98Ah is my intuition here, but I'd like some backup for that.

I recommend instead converting to watt-hour to compare capacity independent of battery quantity or voltage.

 

[MattMan119]

Thanks MattMan!
BTW, is there a way to get email notified when I get a response here?

Glad to help…

Email: click on your name and pick preferences.. there is an email setting… IDK if it works.. but it is there …

 

[Bop]

LOL. I'll try to remember to snap one next time I'm @ the marina.
I do have a question...
So with these 4, 12V, 98Ah batteries connected in series, what is the Ah rating of the whole bank?
98Ah is my intuition here, but I'd like some backup for that.
thx,
Mark

Seconded on the watt hours-your series connection is higher voltage, same Ah ie 4x12v/98Ah batteries is (4x12v) =48v,98Ah or 4x12x98=4704Wh/4.704kWh

Connecting them in parallel gives you a higher Ah, but lower voltage ie 12v, (4x98)=392Ah- but exactly the same storage capacity (12x392 = 4704Wh...)

So you get exactly the same theory storage in both cases (same number of batteries obviously) but you do get the advantage of lower currents (smaller wiring) at higher voltages, so cheaper, plus resistive losses improve with the higher voltage (good old ohms law)