Solar panel compatibile with WFCO 8725

[GuitarPhotog]

I'm interested in adding the ability to keep my TD battery charged with a PV panel on top of my trailer.

I have used a WFCO 8725 Power Converter for AC / DC distribution and charging.

Will I need a new converter, or is there an add-on controller that I can use with solar panels that's compatible with the WFCO?

I read here that the WFCO isn't happy with current being fed to the battery. Is that correct? If so, how does that work with charging the TD battery from the TV?

Thanks,

<Chas>

[8ball_99]

I've been thinking about this also since I have a couple of 15 watt panels sitting in the garage. The only part I'm a little unsure about is running the panels while I'm plugged into shore power.. I figured you could connect the solar controller to the wires between the battery and WFCO. Since you have two different chargers connected together My guess is one would cancel the other out or they would just fight constantly.. Since both are smart chargers if both were on they would think the battery is charged.. Probably the easiest way would be to use a relay so once your plugged into shore power the connection between the battery and solar panels is broken.. Once unplugged from shore power the relay would kick off an the panels would charge the battery.
As far as the charge from the tow vehicle thats easy cause you not charging from your TV while your plugged in.. Even if you did the charger built into the WFCO would just stop charging because as far as it can tell the battery is charged because of the voltage its getting back..

[8ball_99]

After reading one of the stickies, It looks like if you have a Sunchaser 6 or 10. Then the sunchaser will disconnect the solar panel if a better charger is in use.. So if your plugged into to shore power the WFCO should override the solar charger.. to bad I don't have a sunchaser charger lol

[Trackstriper]

How's about a single-pole, double-throw (SPDT) switch? I can't think of any reason to run the solar if you can hook up and run shore power to charge your battery and run 12 volt loads. A switch that would feed the battery from either the solar source, or the converter would make sense to me. It wouldn't be automatic, but you could decide on which charging source you wanted to use for a given camping site. Simple choice, A or B.

I do not know if it would affect a converter if you were on hot shore power and you threw the switch to disconnected the battery load. I would suspect that the converter would have circuitry to prevent any loss-of-load problem.....something to look into.

[8ball_99]

I don't know I think I'd rather use a relay and have it automatic. With a standard SPDT with a 110 AC coil. Just hook the battery to 30 the converter to 87 and the solar panel charger to 87a.. Then hook 110ac from the shore power plug to the coil of the relay.. When not plugged in your battery is connected to the solar charge controller.. When plugged in your battery would be connected to the WFCO. You could always add a switch to over ride the relay if you wanted the solar to charge your battery and just have the converter running your 12v stuff.. The switch would go between the AC power and the relay... Think I just figured out how I'm going to add my solar panels lol

[madjack]

...first let me say I have no WFCO or PV panel(so I truly don't know)...BUT, I do know you havvta have a charge controller between the PV panel and the battery to regulate voltage...further, disparate voltage sources can be connected to the charge controller(additional PV panels, wind generator(s), etc)...the controller takes these different voltage sources, combines 'em and puts out a constant voltage to the battery...soooooo, maybe you can take the DC output(for the battery charger) from the WFCO and run it to the charge controller, along with the PV panel and then run the output from the controller to the battery...I sure as heck wouldn't take what I just said as sound advice without checking with an expert on such things!!!!!!!!!
madjack

p.s. after reading what I just typed, I realized it probably doesn't/won't work thataway since, the charge controller would block the battery voltage from feeding back thru the WFCO to power your 12DC appliances with the battery...if your not confused by now...never mind and if you are still confused...never mind .................mj

[GuitarPhotog]

It seems to me there are three states or conditions of the system.

1. connected to shore power - shore power charges battery and runs 12VDC
2. no shore power - daytime PV panel charges battery what about 12VDC loads like fan?
3. no shore power - nighttime 12VDC loads run off battery

Condition 2 is troublesome if you use a simple SPDT switch to switch the + of the battery from the PV controller to the WFCO.

<Chas>

[8ball_99]

Good point that thought didn't even cross my mind lol. Or the fact that all my radio stations would reset on my radio If you don't have a solar charge controller then I'd get the sunchaser that seems to be able to worth with a converter and automatically switches... I guess me and my cheap controller will just have to figure something else out lol

[8ball_99]

You could still do it more or less the way I was thinking.. Only difference is the relay would be used to either connect or disconnect the solar panel charger to the battery.. No need to disconnect the WFCO and Battery ever. You would just need to disconnect the solar when your plugged in. Only downside is the panels would be just sitting there when you had shore power..

[bdosborn]

Whoa, whoa, whoa, slow down. No need for any type of switching arrangement. Just wire the output of the solar controller directly to the battery and not through the WFCO. The solar controller output is controlled by the battery voltage. If the battery charger is on, the solar controller will read the battery as charged due to the higher voltage from the charger and will shut down the solar output. Solar controllers are designed to work with battery chargers so there's no problem with running them both at the same time.

Bruce

[8ball_99]

Whoa, whoa, whoa, slow down. No need for any type of switching arrangement. Just wire the output of the solar controller directly to the battery and not through the WFCO. The solar controller output is controlled by the battery voltage. If the battery charger is on, the solar controller will read the battery as charged due to the higher voltage from the charger and will shut down the solar output. Solar controllers are designed to work with battery chargers so there's no problem with running them both at the same time.

Bruce

But the issue is wouldn't that work both ways.. The WFCO is also a multi stage charger and will shut off if the battery is charged.. If both chargers are connected to the battery during the day plugged in wouldn't both chargers conflict?

[bdosborn]

But the issue is wouldn't that work both ways.. The WFCO is also a multi stage charger and will shut off if the battery is charged.. If both chargers are connected to the battery during the day plugged in wouldn't both chargers conflict?

Nope, I was worried about that too but the solar controller always shuts down when I plug my charger in.

Bruce

[Bezoar]

So there will be three connections to the battery, right?
1. Solar controller
2. 120 volt Charger
3. "load" to fuse box/power distribution (I opted for charger/converter instead of the AC/DC big panel, since I am having minimal AC - basically the extension cord/power strip set-up!)

[GuitarPhotog]

My loads are connected through the charger/converter, so only two connections to the battery, solar charge controller and charger/converter.

BTW, this thread is almost 10 years old. My WFCO charger/converter died in 2012 and was replaced with a Progressive Dynamics 4045.

<Chas>

[Socal Tom]

What you need is a solar charge controller, you can get one for about $20 on amazon for the PWM version. One side of it connects to the solar panels, another side connects to the battery. Optionally you can connect a power panel to the third set ( since you have the WFCO I would omit that ).

When using sun power, the solar controller will keep the battery charged. When using shore power the WFCO will keep the battery charged, if the solar panels are making power and the batteries are low, the solar controller will also send power, but its won't be much.

Tom