Adding Solar Panels with Existing Generator

[stauffer]

I have a Hunter 410 with a NextGen 3.2kW generator, Magnum 3100 Inverter/Charger, and AGM batteries.

How do I add solar panels to the mix? Do I need a separate controller/monitor or can I utilize the Magnum? How do I isolate and protect the power sources?

All help appreciated!

Jay

[sailorchic34]

Solar needs a separate charge controller, ideally wired direct to the batteries. You will want a charge controler that is compatible with AGM. Not all are, but the better ones will be.

[senormechanico]

You need a solar controller, but you can wire the output to the existing system.
+ to + and - to - in other words, just treat it as an additional source of DC for the batteries.

[stauffer]

Thanks for the responses! So an added solar controller suitable for AGM is needed.

Senormechanico - When you say just wire it to existing system where exactly do you mean?

Jay

[zboss]

Its pretty simple... two wires go to the solar controller from the panels and two go out from the controller to the + and - battery bus which is probably somewhere near the actual batteries. Just look for a place where the generator and the battery charger hook to the batteries.

Or, as suggested... go directly to the batteries from the solar controller.

[stauffer]

Thanks and will do!

Jay

[w1651]

As said first get a controller that can be used with AGM batteries. Also some, not all controllers have a wire hook up to start a generator when the solar panels cannot get the job done. So that is a option worth looking into as well. But the more bells and whistles the higher the cost too.

[LooseGoose]

If your inverter has a battery monitoring kit and display installed, then the new energy source must be routed to the shunt so that the system can track the additional energy going to the batteries.

[SJFK]

If your solar panel charge controller is like ours with 24v and 12v capability, make sure you hook it up to the batteries first so that it recognises the 12v system. Then connect up the solar panel. If you do it the other way around you will find your batteries being overcharged because the charger will default to 24v. As I say it depends on the charge controller you get.

[zboss]

Originally Posted by SJFK

If your solar panel charge controller is like ours with 24v and 12v capability, make sure you hook it up to the batteries first so that it recognises the 12v system. Then connect up the solar panel. If you do it the other way around you will find your batteries being overcharged because the charger will default to 24v. As I say it depends on the charge controller you get.

No only that but you have the chance of frying the controller.

Always hook the controller to the batteries first and never unhook/unplug it unless first cutting the solar voltage off. Also, be sure to use appropriately sized inline fuses throughout.

[stauffer]

Thanks again for the great tips! Hook controller to batteries first to ensure 12v system charging. Unhook panel supply before controller in other direction.

I am starting to get the idea but my concerns mostly center on integration with existing system. Here is what I have:

• Battery bank: (2) 4D AGM house batteries, (1) 31 AGM Engine and genset start

• Magnum 3100 watt inverter/ 160 amp charger w/ remote panel and battery controller

• 40 amp battery charger (back-up)

• Link 10 battery monitor (secondary)

• NextGen 3.5 kw generator

The primary system is the Magnum 3100 which replaced the Link 10/40 amp charger old system. However, when the Magnum was installed the electrician left the old system intact such that it can be selected should there be an issue with the Magnum. So there are side by side charging systems which are supplied by either shore or generator power.


I'd like to add solar as a back-up should shore power trip while I am away as well as to minimize generator dependency away from the slip. My concern is how to properly integrate the solar into the system so it works properly and no damage occurs to any components.


If the solar controller is connected to the battery bus while on shore power I assume the solar controller will stop its own input as it senses charging voltage on the battery system from the dock. If the dock power is disconnected and the battery voltage drops below threshold, the solar would kick in due to the loss of shore power.



As for the generator, it is primarily to run air conditioning. But you have to shut everything else off or it will be overloaded. But would it essentially be the same response for the solar controller to cut out solar supply when the generator is on line?


Is this an accurate understanding? Or is a switch needed to select which source is charging at a given time?



Thanks it you have made it this far!!!


Jay

[BruceS]

That 3100 is only a modified sine wave inverter?
There are combo units made now that do everything in the one unit.
Generator/AC shore power/solar/inverter.
I'm using one but at 48V.

[RaymondR]

Originally Posted by stauffer

If the solar controller is connected to the battery bus while on shore power I assume the solar controller will stop its own input as it senses charging voltage on the battery system from the dock. If the dock power is disconnected and the battery voltage drops below threshold, the solar would kick in due to the loss of shore power.

Jay

Yes, the solar charger will just stop charging the batteries if it senses a higher voltage on the battery terminals than the output voltage it is set to, usually 14.4 on 12V wet cells. Same with any of the other charging sources wired in parallel with the solar.

The only thing to watch for is that none of the charging devices connected in parallel have a maximum reverse voltage than lower than the maximum output voltage of any of the other charging sources, unlikely but possible.

[mitiempo]

Originally Posted by stauffer

I'd like to add solar as a back-up should shore power trip while I am away as well as to minimize generator dependency away from the slip. My concern is how to properly integrate the solar into the system so it works properly and no damage occurs to any components.


If the solar controller is connected to the battery bus while on shore power I assume the solar controller will stop its own input as it senses charging voltage on the battery system from the dock. If the dock power is disconnected and the battery voltage drops below threshold, the solar would kick in due to the loss of shore power.



As for the generator, it is primarily to run air conditioning. But you have to shut everything else off or it will be overloaded. But would it essentially be the same response for the solar controller to cut out solar supply when the generator is on line?


Is this an accurate understanding? Or is a switch needed to select which source is charging at a given time?



Thanks it you have made it this far!!!


Jay

No switch is needed. It is just an additional battery charging system.

Get a good quality MPPT controller - Victron, Morningstar etc.