Progressive Dynamics charger/converter for 2 Trojan T-105’s

Rail Dawg wrote:

Not sure where to begin with my desert boondocking rig but my biggest concern will be wiring.

When not in the desert the rig is stored indoors in Reno with no way to get solar to it.
...

I may have installed my own solar way back when but I’m kind of back to square one in installing solar panels, a charge controller and tying this all into the PD system.

...

For those of you with solar how do you tie all your components together?

My biggest concern with desert boondocking would be A/C. Unless it's a winter. But one must really love prospecting to do in winter. A/C is the only appliance that is nearly impossible to run on "RV-sized" solar.

Roof solar obviously won't work in covered storage. AGM are fine with leaving it for 6-8 months without charging. Just make sure they are full before taking it to storage.

What components to tie? Roof solar is permanently connected to battery, it works no matter if it's with or without generator running. If it's one big 24V panel, then you do what Mex said - run a thin #10 wire to MPPT controller that will lower the volts and boost the amps.

I think one important detail should be mentioned again: the slowest part of charging is from 80-85% to 100%. This is when you should stop wasting fuel and your ears and shut the generator down because battery needs very little current from this point on. 100W solar leaned against the trailer tongue, small controller bolted to the back of the panel, and booster cables clipped to battery might just do the trick. All can be had at Home Depot for $160-170.

Now, 60A converter and big inverter does involve a bit of tying in.

Solar panels - controller - fuse - bussbar - battery exactly same format except for fuse for the negative on this circuit.

Hotel loads (means just about everything else) whether one wire or six, gets connected to the bussbar positive and all the negatives get connected to a negative buss bar.

The huge buss bar negative cable does not run directly to the negative post of the battery.

It runs to a stud on the shutoff switch

Then in continues to the the negative stud.

Never EVER more than one cable to each battery stud.

The same protocol is used for the positive leads but there is no shutoff switch.

Other subject

Take note SOME solar panels and controllers can utilize extremely high voltage from the panels to the controller. THESE ARE THE BEST CHOICE FOR YOU because of small factory installed wire, Get advise on this forum for specifics.

This forum will be around when you need to ask advice. Buy your panels one month the controller the next and an inverter yet another month.

You need to change your interior lighting to LED -- period. Not an option. Might as well get that over with first.

I think this is how it should go:

Solar panel -> DC switch -> Controller-> fuse or breaker -> Pos buss -> battery fuse -> battery.
Controller -> Neg buss -> battery.

Hotel loads -> fuse or breaker -> same Pos buss as above.
Hotel loads -> same Neg buss as above.

I wonder how many permanent solar installs are done this way. Mine is. With portable 100W solar this becomes less important.

Avoiding more than one cable per battery stud is important for higher currents. I have 3 cables on some studs - power, voltage sensing to controller, small (VERY small) inverter.

Yes, changing lights to LED is a must for boondocking.

If rig came with thin factory-installed solar wire, AND if you want solar of substantial size, you have to use high-voltage low-current panels. Those panels are typically from 230W and up. 270W is often same physical size as 230W. Array of 2 or 3 big panels in series is easy to wire, regular #10 cable to controller will suffice.

In desert 300-500W solar will keep you afloat without a generator on those days when you don't need A/C.

Rail Dawg wrote:
Ok so from the solar panel comes the power.Does that power go straight to the busbar?
What else is tied into the busbar and how is the solar power regulated before it gets to the battery?

No, it goes through a controller, then to the bars.

Everything goes to the bars. Solar controller output, 2 chargers' output, feed to inverter, feed from batteries, feed to DC/DC converter ( I run 48v)

OK we're getting on board with the high-voltage solar panel(s) and an MPPT controller.

What is the recommended voltage for the solar panels?

We do prospect in the winter and will only run A/C during hot part of day with generator running.

Would like to get maximum power to the batteries from the solar so please provide some guidance on the panel voltage.

You guys just taught us about MPPT and that's appreciated.

Thanks.

Rail Dawg wrote:
What is the recommended voltage for the solar panels?.

I'm not sure there is such a thing. In my case it was determined by the #10 wires from the roof to the basement. They will max out at about 360w at 12v. I have 835w.

Just keep the panel Voc below the controller Vmax and you are fine.

My controller is 150v max and the panels are maybe 40 Voc so three in series is under 120 volts. Vmp is about 30 volts so it mostly operates at about 90 volts input to the controller. Be very careful of safety of anything above 40 volts.

> Members Solar Installations With Pics

Any MPPT recommendations?

Solar Panels? I'm thinking 24V.

Choosing MPPT controller is the very last stage, after deciding on battery bank and array size - how many of those 24V panels and how many watts each.

Change the light bulbs, meanwhile. I'm not kidding. Mex is right, for boondocker this is not optional.

My controller has max 100V input, 2 panels in series, 64V total input.

In "Members Installs" you will see designs with rooftop junction box - this aspect of "tying it in" may be necessary with 12V panels and PWM controller but can be avoided with 24V panels and MPPT.

Need to know what gauge SAE the factory ran for solar, otherwise planning is nothing more than wishful thinking.