in rare cases replace solar panels with a power supply

[windyboy]

I've seen some comments here and in other places hinting that its possible to replace/switch out the solar panels for a power supply, with appropriate rating's etc and charge the battery bank (higher voltage thank battery bank etc).

Is this a doable solution for occasional backup charging battery bank when low panel output and solid mains AC to power the power supply is available ?

Thanks

[TomW]

windyboy;

Not sure where you are headed with this but I see no problem with it.

Most quality inverters will charge a depleted bank as needed from mains or generator power.

You probably really don't need to do much more than put the charger on the battery. As far as I know inverter / chargers do not disconnect the solar panels while they charge.

May be a gotcha I am unaware of but seems feasible to me.

Tom

[vtmaps]

Not sure where you are headed with this but I see no problem with it.

I suspect that windyboy wants to do this by running the output of a DC power supply through a Classic.  --vtMaps

[Halfcrazy]

You in theory can run a DC power supply into a Classic BUT it may likely be to stiff and cause some damage possibly. I will let boB comment here but I know at work we use power supplies but we also have resistors in series to soften the power supply.

Ryan

[boB]

What is the output rating of this power supply ?  Does it contain its own filter capacitors ?

Another option is to use battery chargers that can be plugged into the wall which is their
purpose.

We use 4 --- 12V chargers for 48V systems to also make sure the batteries in the string
are balanced.

bob

[windyboy]

Interesting

Ryan what kind of power supply are you using, or for that matter what resistors in series to soften the power supply ? 

I'll be honest with you if I can use the same charge controller to charge the battery bank by just adding a power supply instead of panels in case of no sun it seemed less complicated to hook up and automate. Guess I'm trying to be cheap and avoid buying an additional charger for 24V bank or the extra for an inverter with UPS function. But perhaps I'm thinking in the wrong direction ? I really don't want to risk damaging the classic

I wanted to use the diversion load on AUX outputs so I think this would get confused when the battery is finished charging and I'd waste extra energy if it was left

Either way its interesting to know if its doable in case, even if I buy separate charger, in case of back up charging possibilities.

[TomW]

I wanted to use the diversion load on AUX outputs so I think this would get confused when the battery is finished charging and I'd waste extra energy if it was left

Either way its interesting to know if its doable in case, even if I buy separate charger, in case of back up charging possibilities.

The AUX1 and AUX2 will operate even if the source charge is not running thru the Classic. So no real biggie to use it to activate a charger.

I think.

Good luck with it.

Tom

[Vic]

Hi Windboy,

We have been using a Brute Force Power Supply to drive MPPT CCs for some years now.  This simple unregulated is just a 120/240 VAC Transformer,  Bridge Rectifier and about 120,000 uf Filter capacitance (has an output Circuit Breaker and Ammeter as well).

Other PSes have regulated outputs,  and are usually very "stiff".  Here, a Resistor may be required for the MPPT CC to find a good Vmp.  Also,  some of these PSes  might have a CrowBar circuit that SHORTS its output in case of the output exceeding a certain set value.  This short could damage almost any MPPT CC.  In this case a Diode could be used to isolate the Classic's PV + input terminal from the PS,  and help protect the Classic (or other MPPT CC).

A further advantage of DC charging vs using AC into an Inverter/Charger,   is that the generator (or other AC source) need not supply ac loads that are on the inverter output.  This can be handy for off-grid systems.

My opinions,   Good Luck,  Vic

[boB]

We don't really advocate using rectified power lines going into the Classic.  Yes, it can be done
but it may result in operation that could void the warranty in some cases.

The series power resistor is also a good idea to give some Voc to MPP V cushioning
and DC input voltage distance.  If that idea is foreign, you should probably use your
inverter/charger to charge the batteries during times of bad weather.

A lot of people want to rectify the line for some reason  but they usually also have
an inverter with charger built in.   These inverter/chargers are made to charge batteries
from AC.  I highly suggest using that charger with the grid or generator.

You can also buy a 12V battery charger that operates from AC.  Harbor Freight had some of these
for around $30 each recently.  If 24V bank, use 2  12V chargers.  If 48V battery, use 4  12V chargers. 

boB

[windyboy]

Thanks for all the information and confirming many things for me. I'll be getting a seperate battery charger

Thanks again for helping me understand these things better