Simple answer

[jp.beauchemin71]

Hi I'm looking for a simple solution (If possible).

How can I hook up 4 x 250 watt Solar panels. Each panel has a Open voltage of 36V and a Max Voltage of 30V.

Trying to connect that to 4 x 100ah basic deep cycle batteries (12V). I want to wire the batteries in series so I have a 48vdc output.

[dlymn]

get a charge controller that matches input and output. Try aliexpress.

[MarkJ]

Why in the world do you want 48 volts. What can you run on that? No engine starter motor, no fridge, freezer, led light, no inverter... What?

1,000 watts of solar is huge for 400 Ah batteries. You will need a controller for the 36v they are everywhere for 12 volts, some for 24 volts and none for 48 volts.

I have checked back on your previous posts.... You have had some answers that i think assume you have a hgh tech knowledge and high tech boat... Because no boat i know uses 48 volts.

But in one post you say you are 100% novice in solar. Perhaps the answers given to you have not been pitched and what knowledge you really need to have. If ya get what I mean

If you are an electrical expert just say that and i will pull my head in

[GILow]

He has a 48 volt motor that is used as an outboard I believe.



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[barnakiel]

Sounds like yours are 24 V panels. Cannot be wired for 48 V.

Or have I missed something?

b.

[MarkJ]

Originally Posted by GILow

He has a 48 volt motor that is used as an outboard I believe.

$500 says he gets rid of that lil sucker.

[GILow]

Originally Posted by MarkJ

$500 says he gets rid of that lil sucker.

Yeah, I've been down that road. The effort and expense required to get some of the "free" things I have obtained to work far exceeded the cost of buying the right thing for the job in the first place.

But it is a personal journey we all have to make I think, so I am not about to criticise the OP for their choices, lest someone look too hard at some of my choices.

Sigh.

[GILow]

Originally Posted by jp.beauchemin71

Hi I'm looking for a simple solution (If possible).

How can I hook up 4 x 250 watt Solar panels. Each panel has a Open voltage of 36V and a Max Voltage of 30V.

Trying to connect that to 4 x 100ah basic deep cycle batteries (12V). I want to wire the batteries in series so I have a 48vdc output.

jpb, I have thought about this one a little, and I cannot come up with a better option than those suggested to you on the other threads where you find some boost capable mppt controllers and fit one to each panel.

Other than that, one REALLY silly way of tackling this might be put in one additional "house bank" battery @ 12 volts, charge this from the solar in the usual way using a simple and affordable mppt controller (Like my neat little Votronics unit), and then charge the 48 volt engine battery bank from the 12 volt house bank using an invertor and an AC 48 volt charger. Horribly complicated, but I suspect cheapest overall.

I did find a discussion of using individual 12 volt chargers on each of the batteries in the 48 volt bank, but it sounded fraught with problems to me.

[four winds]

I guess I'm missing something as well.

But a solar controller like the 60 amp model from TriStar is available in a 48 volt output version. The input (solar) voltage is up to 125 volts.

So two panels in series, and two pairs parallel into the controller will yield a 96 volt input. That's for 24 volt (open circuit). If these are actually 36 volt open circuit panels then I guess two controllers would be needed or a different controller.

Don't understand why this is not doable.


Edit,....... brainfart, 36 volt open circuit, 4 panels, two parallel pairs in series would be 72 volt input to the controller. So either the TriStar 60 PWM (max 125V input) or the MPPT (150V input ) should work here. ??

Would have to look at max amps input as well.

Or I could be off my rocker, it's not unknown.

[smac999]

wire 2 in series and then 2 parrellel. you will get 72v open circut.

get an MPPT contorler for 48volt output that can handle 72volt input, and can handle ~25 amps.

like this one, it would work great.
https://www.victronenergy.com/upload...-150-35-EN.pdf

[GILow]

Series is not going to be great in this scenario because without a boost capable controller any shade on one of the panels risks reducing charge to zero when the combined panel voltage falls below 48 volts, which it will do. And let's face it, it is very hard to avoid shading on a boat.


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[jp.beauchemin71]

yes its mainly for running my 48volt outboard. My house current is tiny a few LED lights and charger for cell and table. So would this work: I wire the Panels so they put out 72V. Use this MPPT (It's the cheapest 40A I could find that will handle 72in - 48 out).Then use a completely separate small system for house power.

[jp.beauchemin71]

My roof is nearly flat and I dont think shade will be a huge problem.

[jp.beauchemin71]

My roof is nearly flat and I dont think shade will be a huge problem.

[four winds]

A seperate house system would be common practice I think. There's always ever more complex options and costs.

Assuming a house 12 volt system, then a charging method for the house must be considered. Maybe a 48 volt inverter, 110 ac outut, and a shore power charger.