Solar Installation - Lessons learned and tips

[05bill]

question: 2, 150 watt solar panels in series going to a 30 amp controller connected to a agm battery. now ,on that same system is an inverter/charger. the question, can i run shore power and solar together without shutting solar system off or will the solar controller and the inverter/charger recognize each other ? or for that matter when underway when both solar and alternator are charging battery ?

thank you Andy

 

[Jason S]

Andy, thank you. That’s a lot of info and clears it up for me.

 

[Genius]

question: 2, 150 watt solar panels in series going to a 30 amp controller connected to a agm battery. now ,on that same system is an inverter/charger. the question, can i run shore power and solar together without shutting solar system off or will the solar controller and the inverter/charger recognize each other ? or for that matter when underway when both solar and alternator are charging battery ?

thank you Andy

all they do is look for voltage, then charge the appropriate value. So, if you have two voltage sources (alternator or charger) the devices may not be on their algorithm for 3/4/5 stage charging, but most probably a bulk stage. Anyway, that's how I imagine the systems working together. At this point you are likely using from the battery bank so I don't think it really matters.

 

[05bill]

all they do is look for voltage, then charge the appropriate value. So, if you have two voltage sources (alternator or charger) the devices may not be on their algorithm for 3/4/5 stage charging, but most probably a bulk stage. Anyway, that's how I imagine the systems working together. At this point you are likely using from the battery bank so I don't think it really matters.

Thanks Dave I think you are correct .

Bill

 

[andy65]

all they do is look for voltage, then charge the appropriate value.

Looking at voltage only can be a problem as they don't look at current. Suppose the boat is underway and the batteries need a charge. Solar is on putting out 5 amps at 14.5v to the battery. How will the alternator's regulator behave when it sees solar's 14.5v at the battery? Perhaps it won't send any current to the battery because the battery appears fully charged. So the batteries charge at 5 amps from solar instead of 50 amps from alternator. Probably won't hurt anything but may take a long while for the battery to charge. Or, the alternator may keep sending amps as long as the battery will absorb. Depends on the regulator. Whether the regulator cut out voltage is slightly over or under the solar cut out may be a factor.

How will a battery isolator behave if one is installed? They direct the charge to the lowest voltage battery bank. With solar on underway, what voltage will the isolator see?

In general, I'm not a fan of two charging sources operating simultaneously into one battery.

Probably won't hurt anything short term. But long term, battery life?, so much depends on the equipment installed. Some people leave solar on underway. Other's don't. Just because it works fine on one boat doesn't mean it will on another.

 

[05bill]

Looking at voltage only can be a problem as they don't look at current. Suppose the boat is underway and the batteries need a charge. Solar is on putting out 5 amps at 14.5v to the battery. How will the alternator's regulator behave when it sees solar's 14.5v at the battery? Perhaps it won't send any current to the battery because the battery appears fully charged. So the batteries charge at 5 amps from solar instead of 50 amps from alternator. Probably won't hurt anything but may take a long while for the battery to charge. Or, the alternator may keep sending amps as long as the battery will absorb. Depends on the regulator. Whether the regulator cut out voltage is slightly over or under the solar cut out may be a factor.

How will a battery isolator behave if one is installed? They direct the charge to the lowest voltage battery bank. With solar on underway, what voltage will the isolator see?

In general, I'm not a fan of two charging sources operating simultaneously into one battery.

Probably won't hurt anything short term. But long term, battery life?, so much depends on the equipment installed. Some people leave solar on underway. Other's don't. Just because it works fine on one boat doesn't mean it will on another.

Probably will isolate house battery from alternator while under way.

However at dock, shore power and solar simultaneously . A problem ?

What I plan on doing is using solar to charge batteries while moored. In order to run microwave, coffee maker for short period of time use generator to run the ac through inverter to microwave and coffee maker. Now do I need to shut off solar during that short period of time or can I run both systems together ?
Hoping I can run both systems together , again short period of time ?
Thanks,

Bill

 

[andy65]

However at dock, shore power and solar simultaneously . A problem ?

What I plan on doing is using solar to charge batteries while moored. In order to run microwave, coffee maker for short period of time use generator to run the ac through inverter to microwave and coffee maker. Now do I need to shut off solar during that short period of time or can I run both systems together ?
Hoping I can run both systems together , again short period of time ?

Shore power and solar simultaneously: Two devices charging one battery. Same concerns as mentioned previously. They fight each other. I don't understand why you would want solar on when shore power can supply all needed power.

Generator and solar simultaneously: If the generator only supplies AC and does not charge the house batteries, I don't see a problem with solar on. If the generator is wired to an inverter and the inverter converts generator AC to DC and then charges the batteries when the generator is running, that's two devices charging one battery. Same concerns as mentioned previously. Would you run shore power and the generator simultaneously?

 

[Jason S]

I’m glad you guys are discussing this because i didn’t even consider it… so i don’t want the alternator and the solar charger competing, meaning i should switch it off before going underway? Do i install switch before the charge controller or before the battery? Any recommendation for a smaller switch to use for 10awg wire?

 

[05bill]

On a mooring for a couple of days , solar charging battery connected to inverter/ charger that runs ac items. Now battery alone will not run my microwave nor the coffee maker efficiently but will run continuously the refrigerator.

So I use a portable generator through shore power cord through the inverter / charger to run coffee maker and microwave for a short period of time than shut off.

During the time that I am running the generator will I harm anything if I keep the solar going during that short period of time ?

I hope I am making sense here ?

Thanks

 

[Genius]

On a mooring for a couple of days , solar charging battery connected to inverter/ charger that runs ac items. Now battery alone will not run my microwave nor the coffee maker efficiently but will run continuously the refrigerator.

So I use a portable generator through shore power cord through the inverter / charger to run coffee maker and microwave for a short period of time than shut off.

During the time that I am running the generator will I harm anything if I keep the solar going during that short period of time ?

I hope I am making sense here ?

Thanks

No. Yes.

 

[05bill]

No. Yes.

Dave no to problematic to do it that way ,yes to I am making sense ?

Andy, not sure if inverter / charger powers ac requirements directly or/ and by converting AC to DC to charge battery at the same time.

Maybe I am over thinking this. Don't want anything to blow up !!

 

[05bill]

thanks all, i think i got this !!!

 

[andy65]

So I use a portable generator through shore power cord through the inverter / charger

If the portable generator is connected through the shore power receptacle on the boat, power goes to the boats battery charger which will charge the batteries. So there will be two devices charging the batteries simutanously solar and portable generator. Just flip the switch and turn solar off. Then you won't worry and definitely won't have a problem.

 

[05bill]

If the portable generator is connected through the shore power receptacle on the boat, power goes to the boats battery charger which will charge the batteries. So there will be two devices charging the batteries simutanously solar and portable generator. Just flip the switch and turn solar off. Then you won't worry and definitely won't have a problem.

yes , i will put a breaker prior to the solar controller and after the solar controller but before battery and shut one or the other off.

however ,Genius may have a point here , if the inverter/charger has a different setting for charge than the solar controller , will the device with the higher setting continue to charge and negate the lower setting device ?

interesting question ?

bill

 

[andy65]

Andy (not Genius) may have a point here , if the inverter/charger has a different setting for charge than the solar controller , will the device with the higher setting continue to charge and negate the lower setting device ?

Actually, it was me, Andy65, making that point. Wouldn't want good old Genius to get blowback from my musings.

 

[05bill]

After a couple of field trips ,system working well .

Refrigerator running, radio on , lights on and all is well . Charging during day ample for nite use.

Disconnect solar ,use generator for microwave , coffee maker. All is good . Should have done it sooner.

 

[andy65]

My inverter/charger died so I’ve relied totally on solar awaiting a replacement. Solar has kept the fridge running and the batteries are fully charged on float every time I’ve gone to the boat. After an overnight on the boat using lots of power, solar brought the batteries back to full by early afternoon. Have seen 11 amps if the batteries need it. I turn solar off when underway and when on shore power.