2 to 3 solar panels

[SteveJ.]

Originally Posted by JHinman

I wonder if Battleborne meant 200 watts of solar per amp-hour of battery, not 200 amps.

Watts = amps times voltage, so 170 watt panel with a nominal output of 18 volts provides 9.4 amps. Remember that the rated wattage is for ideal conditions, so in actual practice you might get 2 amps or less at times.

I am not clear on how the W = A x V relationship is affected by the solar controller. My panels produced at 18 volts, but the PWM controller provides 13 to 14 volts to the batteries. I don’t know if the power (watts) stays the same, or if there are significant losses in the controller itself. Maybe someone with more expertise than me can clarify.

The way I understand it a PWM controller just wastes the power from excess voltage, MPPT controllers convert higher voltages to more/faster charging. MPPT controllers are particularly good at charging under sub optimal conditions when the panels are set up in series for even higher input voltages. Our setup is 2s2p of 60 watt portable panels, nominal input voltages are in the mid 30's.

[National 350]

Originally Posted by varmonter

Just put a downpayment on a
28dbs. it came with 2 170watt
solar on the roof. since we will be
boondocking i was wondering
if a 3rd might be better. from what ive read i can install up to
4 with the stock controller and
batteries (2 12v) is this true or
will i need a different controller
and or more batteries??

I have two 150W panels on roof and wish I had a third....when boondocking I need to run generator after third day if I use too much electricity.....after gen brings batteries up I'm good for another two days.

[PeterFTH]

2 x 170 watt panels is not a lot of power. I would definitely add a 3rd and wire them in series. There are some issues with shade in this configuration, but the controller will work better with the higher voltage of series. The other question is - what is the capacity of your controller? I just went from 500 to 850 watts (adding a 3rd panel) and had to upgrade from my 45 amp controller to a 60 amp MPPT (Maximum power point tracking) - this is the type of controller you want BTW.

[MTScruff]

I have a Creekside and a 100w panel on the top and it does fine for 3-4 days boon docking. You may want to try it as is because it might be plenty of power. We camp in mostly Montana.

[lshantz]

Originally Posted by varmonter

Just put a downpayment on a
28dbs. it came with 2 170watt
solar on the roof. since we will be
boondocking i was wondering
if a 3rd might be better. from what ive read i can install up to
4 with the stock controller and
batteries (2 12v) is this true or
will i need a different controller
and or more batteries??

Can you have too much power? Nah. I say put as much as you can! We have 1,500 watts up top and would not mind more. I can never have enough horsepower either.

[LargeMarge]

On our ExpeditionVehicle, we installed six 305-Watt photovoltaic panels, a total of 1,830-Watts.
.
These feed our ancient bank of Concorde LifeLine 105ah AGMs.
For us -- full-time live-aboard, boondocking exclusively for nearly two decades -- this makes sense, economically and for the peace d' mind of an experienced system.
.
We rarely draw more than a couple-three percent.
If we were heavier users, I could see replacing everything with new.
But we are light, so we will pass.

[varmonter]

I met an outdoors rv 5th wheel owner tonight.
they primarily boondock. 510 on the roof.
and lithium
his camper is a 2020. He said he had to change
the controller and the converter/charger
in order to use lithium..??

[Kmlac]

To the OP.
A third panel will charge faster. The Zamp 30 PWN solar controller is fine for "occasional use". If you will be off shore power for long periods of time, a PWM is quite a bit less eficiant than a MPPT controller. The Zamp 30Amp will take 510W at 12 volts or 1020W at 24 volts. Same amps.


What will be effective depends on how much power you use, size of battery bank, season, latitude, amount of sun exposure.


For example the fist several hours today were cloudy, but clouds diminished through out the day. I have 3 175w 12v solar panel on my 280rks. I changed the controller to a Victron 150/35. I generated 740Wh's. I am a 9000' in southern Colorado with very good sun exposure. Panels a flat to the roof of the camper. I feed 2, soon to be 3, 206Ah LiFePO batteries.


A third panel will help. If you are handy you can add one yourself and save $$.

[JHinman]

My2021 ORV had both converter and solar controllers that were able to charge lithium batteries. The change to lithium-compatible controller was pretty recent.

My 2011 Arctic Fox had a Progressive Dynamics converter with Charge Wizard. Instead of spending $200 on a new converter, Battleborne suggested I spend $19 on a Charge Wizard Pendant. That got the job done.

Both the Arctic Fox and the ORV converters were rated at 60 amps. I could get only 20 orv25 amps into my Battleborne batteries. This is probably due to the light wiring. Upgrading to lithium might not require a new converter, but upgrading wire size and making the wires shorter might help realize the fast charging potential of the LiFePo batteries.

[Our05Winneba]

Adding solar panels is relatively cheap and easy. If you want to improve your RV look at building the battery system 1st.

If you can afford them go with Lithium as they works so much better. They also offer greater usable range as well as operating at higher voltages. But it is your overall battery bank that you need to develop, because having lots of solar does not help you at all at night, during bad weather or when parked in shade. But having a good battery bank is what makes all the difference during those times.

Also suggest that you install a good BMS - battery monitoring gauge - such as the Victron 712. This is priceless in enabling you to monitor accurate charge states as well as seeing how much power is actually going into and out of your batteries.

[Cumminsfan]

IIRC ORV now installs the PD charger. Not sure if it comes with the pendant but that would be a cheap upgrade.

[Npkp]

We have 3 200 watt solar panels connected to a Victron 100-50 mppt smart controller, which goes to 4 Deka 100ah solar batteries. I converted my fridge to a JC AC compressor and everything else inside and out runs just fine. No air conditioning but lots of circulating fans running continuously.