Solar Panel Question

[Bill/Kathy]

Our 2014 Chateau has a small solar panel. Is this factory installed? The indicator light says it is charging, but charging what? The only thing I can think of would be the coach batteries. Would this be correct?

[blw2]

my guess is aftermarket. Was this purchased new or used?

i don't have one, and I don't recall ever seeing such a thing in the options list....

You say small, so my guess is it's one of those trickle charger panels. I'll bet if you look at the batteries, you'll find the small gauge wire leads coming from the panel, or controller if there is a separate one, landing directly on the batteries.... either the house battery(ies) or the chassis battery.

[jpmihalk]

Our 1998 Itasca had a similar 10 watt trickle charger that went through a diode to indicate that it was "on" (charging) and was wired directly to the house batteries. It was supposed to offset any parasitic draws on the batteries while in storage. Your solar system sounds very similar.

[wredman]

how much solar capacity is sufficient to trickle charge/maintain

a) 1 chassis battery
b) 2 house batteries with typical parasitic drain while in store mode

Would it be best to have 2 separate chargers to maintain these 2 separate systems? Thinking that splitting a single solar input to both battery banks would provide an alternative connection between these 2 that is not desirable.

[jpmihalk]

I would go with at minimum a 100 Watt solar panel if a trickle charge is all you want. Yes, they sell smaller panels but for deep cycle batteries they just don't do much. I would only worry about connecting to the house batteries, the chassis battery is usually separate and has less parasitic draws.

[wredman]

100 watts of trickling seem like a lot. ??

[jpmihalk]

Originally Posted by wredman

100 watts of trickling seem like a lot. ??

I say this based on experience. There are several parasitic loads on typical house batteries. 100 watts is probably overkill on bright sunny days, but on cloudy days it may only provide a fraction of the potential power needed to maintain the batteries. Our old coach had a 10 watt panel on the roof attached to the house batteries and it didn't even come close to keeping up even on sunny days. So it does seem like a lot, but it is planning for the worst case.

We currently have 400 watts of solar on our roof and are looking at adding to that since our power budget has gone up. Of course, we also have 4 group 31 AGM batteries for the house as well and they take a lot more power to charge them fully. So we end up running the genny more than we would like.

[Peterrrr]

Originally Posted by wredman

how much solar capacity is sufficient to trickle charge/maintain

a) 1 chassis battery
b) 2 house batteries with typical parasitic drain while in store mode

Would it be best to have 2 separate chargers to maintain these 2 separate systems? Thinking that splitting a single solar input to both battery banks would provide an alternative connection between these 2 that is not desirable.

Your house and chassis batteries are already connected together. You would only need one solar charge controller normally connected to the house terminal post of your coach. Your battery positive is connected to this.

I agree with John that 100 watts would be needed.

[gmc]

Originally Posted by Peterrrr

Your house and chassis batteries are already connected together. You would only need one solar charge controller normally connected to the house terminal post of your coach. Your battery positive is connected to this.

I agree with John that 100 watts would be needed.

In a properly functioning system, the house and chassis batteries are ONLY connected when in 'USE' with one of the engine, generator, or shore power providing voltage to the system.

The BCC or BIRD/Trombetta depending on the rig provides the connection/isolation.

Solar connected to the house batteries with switch in STORE will only charge the house batteries.

A good chassis battery should be able to go a month or more without an issue or charge.
A proper STORE setup should as well for house batteries... but many find it easier to leave on charge of some sort or add an additional disconnect than spend the time finding the improper draw.

My rig was unplugged and in STORE from July 12 (return from trip) till September 9 (fired genny then engine to exercise in prep for Irma...) All batteries were fine. No extra disconnects in use.

As for how much current you need - measure the draw when in STORE - that draw over 24 hours is what you need to replace at a minimum in daylight hours with solar... And of course not all days are sunny. Not know what is actually still 'on' in your rig makes it difficult to estimate.

[Bob Denman]

I've been following the solar panel discussions with a lot of interest.
But I still don't feel as if I've learned enough, to be able to make a good decision about them.
I know that a pair of 165 watt panels would fit, and are readily available...
What else would I need to purchase, if the rig is already wired for solar panels?
(2018 Class C Outlaw...)
And what do I hook it up to?

[DenverTransplant]

We have a 100 watt "suitcase" unit we use while dry camping and which I keep connected to the motorhome while its in storage. I just sit it on our car dolly which faces south east. We get good morning sun, but by noon in the fall/winter the shadows basically kill production. Its plenty for keeping the batteries topped off though, especially in Colorado when it's sunny all the time and we are closer to the sun. I can locate it where it gets more sun, but then its not hidden behind the motorhome. We are in a secure lot but I'd rather not provide more temptation.

The controller is a cheapie that is integrated with the panels and probably doesn't do that great of job do much other than maintaining battery charge. For example it doesn't have any equalize functionality.

We recently added a Trimetric Battery Monitor so I can monitor how the solar paneling batteries are doing. I'm thinking of adding the SC-2030 solar controller and getting rid of the cheap controller that came with the panels. The SC-2030 controller integrates with the battery monitor and allows you to set float voltages and equalize behavior. Eventually I'll add permanent roof top solar panels.

[gmc]

Originally Posted by Bob Denman

...
I know that a pair of 165 watt panels would fit, and are readily available...
What else would I need to purchase, if the rig is already wired for solar panels?
(2018 Class C Outlaw...)
And what do I hook it up to?

You would have to buy everything but the wire... lol
'Wired for solar' means just that - they ran a wire up to the roof - an exercise for the user to find the ends - and to insure it is sufficient gauge to meet your needs.
The solar controller will go between the panels and the battery - and manages the charging... How much you pay for the controller is a direct correlation to how much it will do for you.

[Bob Denman]

Originally Posted by gmc

You would have to buy everything but the wire... lol
'Wired for solar' means just that - they ran a wire up to the roof - an exercise for the user to find the ends - and to insure it is sufficient gauge to meet your needs.
The solar controller will go between the panels and the battery - and manages the charging... How much you pay for the controller is a direct correlation to how much it will do for you.

Thanks!
Based upon your answer: I now know that everything needs to (somehow) end up where the coach batteries are kept.
I seem to recall that a 30 controller can easily handle 330 watts...
Now, it's just a matter of getting my courage screwed on tight!

[jpmihalk]

There are more than one type of solar controller that can be used, depending on what you are trying to do.

For most cases, anything 400 watts and under can use a PWM controller which will usually provide up to 30 amps to the batteries. PWM = Pulse Width Modulation and is good for running 12v panels in parallel. For cases over 400 watts or when using other voltages (24v?) you will want an MPPT controller (MPPT = Maximum Power Point Tracking) which is for higher end situations, such as running your panels in series or mixed modes (series and parallel.) MPPT controllers cost more but are generally very programmable to meet whatever need you may have. PWM controllers are typically what come in the basic kits as they don't really need to do much, but some can be programmed to maintain certain types of batteries (Sealed Lead Acid, AGM, etc.) and some can also maintain charging based on the temperatures in the battery compartment with a separate thermometer probe. The controllers in the suitcase kits are almost always simple pre-programmed controllers for sealed lead acid batteries.

[Bob Denman]

TONS of great info! Thanks!

[camperguy99]

I have a 2015 Tuscany 40DX that is quite power hungry being all electric coach with a large residential frig (108 watts all the time.) I bought a CNBOU 40 amp MPPT controller in Quartzsite last February thinking of going solar. My 40DX had 10 gage wires up to the rear AC. I got 4 Canadian Solar 180 watt 3 year old hail damaged (none showing) for $95/each. I wired them as 2 in series in parallel with the other two so about 10 amps max in the 10 G wires. Here in Northern CO the first day of fall I was getting 33 amps charge into the bank of 4 GC2's. Pretty happy with about 500 watts delivered from 720 spec'd power from the 4 180 watt panels. Total cost was a little more than $730. Hopefully my solar will keep up with the static drain (maybe 150 AH per day) from the coach? Happy camper!

[jpmihalk]

Originally Posted by Bob Denman

Thanks!
Based upon your answer: I now know that everything needs to (somehow) end up where the coach batteries are kept.
I seem to recall that a 30 controller can easily handle 330 watts...
Now, it's just a matter of getting my courage screwed on tight!

Actually, the controller does not need to be where the batteries are kept. It should be in close proximity but needs to be able to be easily seen (or read, if using a digital controller) so you can see the state of the charge. Ours is mounted on the wall of our RV right behind the driver seat in front of the slide, and the wiring from the roof runs down to it, the wiring to the batteries goes directly down to the battery compartment. There was no pre-wiring for our solar config, so we just did it ourselves and used lots of Eternabond tape and Dicor sealant.

[jpmihalk]

Originally Posted by camperguy99

I have a 2015 Tuscany 40DX that is quite power hungry being all electric coach with a large residential frig (108 watts all the time.) I bought a CNBOU 40 amp MPPT controller in Quartzsite last February thinking of going solar. My 40DX had 10 gage wires up to the rear AC. I got 4 Canadian Solar 180 watt 3 year old hail damaged (none showing) for $95/each. I wired them as 2 in series in parallel with the other two so about 10 amps max in the 10 G wires. Here in Northern CO the first day of fall I was getting 33 amps charge into the bank of 4 GC2's. Pretty happy with about 500 watts delivered from 720 spec'd power from the 4 180 watt panels. Total cost was a little more than $730. Hopefully my solar will keep up with the static drain (maybe 150 AH per day) from the coach? Happy camper!

Very nice!!

[Bob Denman]

Originally Posted by jpmihalk

Actually, the controller does not need to be where the batteries are kept. It should be in close proximity but needs to be able to be easily seen (or read, if using a digital controller) so you can see the state of the charge. Ours is mounted on the wall of our RV right behind the driver seat in front of the slide, and the wiring from the roof runs down to it, the wiring to the batteries goes directly down to the battery compartment. There was no pre-wiring for our solar config, so we just did it ourselves and used lots of Eternabond tape and Dicor sealant.

Attachment 7158

I hadn't thought about keeping it visible... Thanks again!

[rsgarrett]

My 2018 Compass is wired for solar. I see the connectors on the roof, but where do the wires come out?