Solar Install Questions

[Mister Blu]

Recently purchased a basic 100w solar kit, and am looking to install over the following week.

Stock electrical system in 1986 Sunrader.

Battery isolator was bypassed by previous owner.  Not so concerned about an isolator.  May turn my attention back to that later in the year.

My questions today pertain primarily to the installation of solar panels and charge controller, in conjunction with existing electrical system.

Perhaps someone has a convenient and clear diagram that I can follow.

Am I able to safely hook directly from new controller to batteries?

Is it better to splice into hot and ground wires that come from existing converter to battery bank?

Currently I only have a single 12v deep sycle for the coach.  Will look to upgrade to a couple of Trojan T-105's, along with an additional 100W panel.  One panel will be roof mounted, and the other I hope to make were I can lead out up to 50' from r.v. for better sun.

Will I need to get a new and better converter?  

Will I need a " transfer switch?

What about a smart battery charger?  

Safety is first priority.

Budget is tight.

Looking forward to your feedback.

A preemptive thanks to all.

 

 

[Mister Blu]

Expected DC load sources is are:

The ignition for water heater, furnace, fridge (on propane mode); l.e.d. lights; waterpump; periodically recharging iPad and lithium batteries in camera.

Will also use small inverter to charge laptop, sonicare, and occassonally Dewalt 20v batteries after new battery bank is acquired.

 

 

[WME]

So many questions and so little time. 100w is border line for boondocking solar, OK for a few days.

Things to do BEFORE solar install.

Convert to LED lights,  get a new isolator, they are cheap.

Random answers

If you camping style includes a lot of boondocking, then your current converter is OK, more camp grounds than boondocking? then up grade the converter.

Kinda sorta rule of thumb... 1 w solar for every 1AH of battery. Your 100w panel will support 100AH of battery..

Remember the max safe charge rate for lead acid batteries is C/10. So a 100 AH battery can be safely charged at 10 amps. 100w solar = 6 amps

A 100w panel will do about 30AH per day, 200w about 60 AH.

The SAFE discharge for Lead acid batteries is 50% of rated capacity. 50% gives you a life cycle of 1500 charges, 80% discharge will give you 850 charges. The OCCASIONAL OOPS will not greatly harm your battery . So 50% discharge will slowly deplete your battery, because your are only charging 30 AH. Answer less load or more solar

Most solar controllers will have 3 connections, solar panel, battery, load. Just use solar and battery and you will be fine. hook direct to battery and leave exhisting wires attached where they are.

Smart charger = smart controller.

No transfer switch needed

Have fun

 

 

[Mister Blu]

Thanks for the input WME.

Recap:

1) no transfer switch necessary.

2)acquire a second 100W Panel.  Extra input will help preserve battery life.

3)smart charge is same as smart controller. (What is the 30A PMW controller?  Is this sufficient?)

4)mainly boondocking, some shore power hook up.  Need I concern myself with replacing/upgrading o.e.m. converter?

Additional questions:

A) Do you mean to say itnis best for me to run wires coming from 'battery' ports directly to battery?

B)Is new underhood isolator necesary?  (Current isolator is disconnected)

C) Are there any issues with having power source coming from alternator via isolator and solar at same time?

D) what, if any, are the issues with plugging into shore power while having solar input? (Conflicts?)

To confirm:

It is okay to connect wires coming from charge controller directly to battery, while keeping existing wiring untouched?

[WME]

What solar controller do you have. Does it have charge, float and equalize functions?? Most of the good controllers do.

The isolator is a safety device, it keeps you from running the truck battery down during an extended boondock stay and having a no start situation. Is it "necessary" thats up to you.

Mount the controller where you can easily see it. Run 8 ga wires from it directly to the battery.

What ever has the highest voltage, alternator, converter or solar controller will bring the battery to that level and the other devices will shut off when their internal trigger max voltage is reached. SO no conflicts or problems.

Your converter is most likely old school, only 3-4 amp charge and no regulation. If you rv park csmped a lot then it would be a desirable up grade to extend battery life. If mostly boondocking then you won't use it much and you will be OK.

[Mister Blu]

Charge controller is the Renogy Wanderer 30A with 4 stage charging.

No digital readouts.  Only led signal light.

Considering upgrading to one with read outs so I can better monitor the voltage, amperage, etc.

So, what I hear you telling me is that I can go ahead and install a new isolator to replace the original, and have that charge batteries, along with solar, and still have original converter in the chain?

All without causing a conflict and possibly overcharging batteries, or worse? 

[WME]

Unless you up grade to an MPPT controller, there easier ways to monitor your battery. This is a simple, useful thingie. https://www.ebay.com/sch/i.html?_from=R40&_nkw=12+v+usb+volt+meter&_sacat=6028&LH_TitleDesc=0&LH_PrefLoc=1

The Wanderer is a simple hookup. It does not have a load set of contacts

Your charging system is NOT a chain. It will be 3 charging systems in parallel. Which ever one has the highest voltage will be where the battery will go. Most of the time it will be the alternator. With the engine off the converter will be the high voltage. With no engine, no 110v to the converter, the solar controller will set the voltage.

So you cant get 36v to your battery. 

[Maineah]

Lot of questions, no on the converter no on the transfer switch yes on number one if you want to upgrade. Reconnect the isolator, yes you can connect the solar directly to the batteries via a solar controller. 50' is a good run use at least a #12 wire 10 would be better use stranded wire , install the charge controller in the RV run full solar voltage to it if you are going to use two panels series wire them and use a 24 volt controller with a 12 volt output. The panel voltage will be in the 20 volt range unregulated so you need to see battery voltage only it will be the only way to tell what you have going on. There are any number of charts online that will give you voltage versus state of charge.

 

[jmowrey]

18 hours ago, Mister Blu said:

Charge controller is the Renogy Wanderer 30A with 4 stage charging.

No digital readouts.  Only led signal light.

Considering upgrading to one with read outs so I can better monitor the voltage, amperage, etc.

So, what I hear you telling me is that I can go ahead and install a new isolator to replace the original, and have that charge batteries, along with solar, and still have original converter in the chain?

All without causing a conflict and possibly overcharging batteries, or worse? 

If you are going to replace the controller you may want to consider getting a dual controller (with two charging outputs). That way you can have your solar panel trickle charge both the coach battery and the vehicle battery during the winter months. That's if you live in a cold climate. We use this kind of system for our Dolphin and it works great to preserve the batteries during the off season. Also, we didn't mount the panel on the roof. It hangs on the wall in the bathroom while we are on the road. The cable which connects it runs out from the electrical door on the side and is about thirty feet long. That way we can plug the panel in when we are set up and move it around to capture the best sun. I have a simple wooden stand attached to it so I can place it at the optimum angle for the sun too. Since parking in the shade is always a priority when camping, you won't get much in the way of charging with the panel mounted on the roof. All depends on where you do most of your camping. If you are always going to be in the sun, then roof mounting would work okay.

[Maineah]

So, what I hear you telling me is that I can go ahead and install a new isolator to replace the original, and have that charge batteries, along with solar, and still have original converter in the chain?

All without causing a conflict and possibly overcharging batteries, or worse? 

Yes everything is very well voltage regulated except your original converter but it only works when plugged in and is fine short term do not leave it on long term. A modern one will not over charge and can be left on long term. With your original converter/charger it actually disconnects your coach battery when plugged in. All of the modern equipment alternator included is voltage sensitive so it folds back when the batteries reach full voltage so if the solar or other devices reaches full voltage the other devices see that the battery is full charge and react accordingly. I have gone 2 weeks with just a 100 watt panel and two 80 amp batteries the key here is conservation of power.

Edited June 20, 2018 by Maineah

[Mister Blu]

Jmowrey: 

Do you have a particular charger you recommend?  Have a limited budget.  Renogy is preferred.  Have not seen any "dual controllers".   Will these charge the two flooded Trojans in coach, and an AGM under the hood?

Will like to have one 100w panel on the roof, and another that i can take up to 50 feet from coach to get better sun.  Unsure of how I would connect these.  Perhaps run wire from panel on roof into coach, and splice second panel into this wire just before the charge controller?  Is there a maximum distance that each panel can be from one another?

 

 

 

 

 

[Maineah]

18 hours ago, Mister Blu said:

Jmowrey: 

Do you have a particular charger you recommend?  Have a limited budget.  Renogy is preferred.  Have not seen any "dual controllers".   Will these charge the two flooded Trojans in coach, and an AGM under the hood?

Will like to have one 100w panel on the roof, and another that i can take up to 50 feet from coach to get better sun.  Unsure of how I would connect these.  Perhaps run wire from panel on roof into coach, and splice second panel into this wire just before the charge controller?  Is there a maximum distance that each panel can be from one another?

Panels don't care. If you splice them wire them in series then buy a 24 volt controller with a 12 volt output. It will be tricky to try and charge all of the batteries at the same time because if you connect the truck battery you will be eliminating the isolator running a risk of a dead truck battery. I don't know where you live but there probably is a battery shop somewhere near you I'm in the middle of nowhere but there is one within an hour  of me they probably can help you real time. 

[Mister Blu]

Maineah:

Not quite sure if I understand your statement about "connecting the truck battery".

Was not intending on combining truck battery in with the coach batteries in any other fashion than perhaps through the isolator.

At most, I aim to have two Trojan t-105 6v batteries for the coach.

The truck battery is currently of the AGM type.

by question regarding the truck battery only had to do with replacing existing isolator under the hood, and if there was any conflict with having AGM (truck battery) being charged from alternator, and the coach batteries(flooded) also being charged by alternator via the isolator.

Perhaps that is whatbyou we're referring to?

What do you mean when you say if I "...try and charge all of the batteries at the same time because if you connect the truck battery you will be eliminating the isolator running a risk of a dead truck battery"?

 

 

[Mister Blu]

To clarify...

If i were to install a new isolator to replace the old one, I can have the new isolator to coach system (flooded batteries) as well as to the truck (agm battery) without problems or concern?   

 

Thanks for the pointers all.

 

Edited June 20, 2018 by Mister Blu

[jmowrey]

18 hours ago, Mister Blu said:

Jmowrey: 

Do you have a particular charger you recommend?  Have a limited budget.  Renogy is preferred.  Have not seen any "dual controllers".   Will these charge the two flooded Trojans in coach, and an AGM under the hood?

Will like to have one 100w panel on the roof, and another that i can take up to 50 feet from coach to get better sun.  Unsure of how I would connect these.  Perhaps run wire from panel on roof into coach, and splice second panel into this wire just before the charge controller?  Is there a maximum distance that each panel can be from one another?

 

https://www.ebay.com/itm/Renogy-10A-Solar-Panel-PWM-Dual-Battery-Charge-Controller-Regulator-12V-24V/301106194644?epid=1127922573&hash=item461b53e8d4:g:TMcAAOSwEnlZ4F9z

This is the one I have. I've been using it for 4 years with no problems. We only have one 100 watt panel though. You may need something with higher amperage for two panels. I'm not an electrical guy. A friend set up our system for us.

There are other dual controllers at eBay. I haven't checked Amazon.

Good luck with your install.

Joe

[Maineah]

4 hours ago, jmowrey said:

 

https://www.ebay.com/itm/Renogy-10A-Solar-Panel-PWM-Dual-Battery-Charge-Controller-Regulator-12V-24V/301106194644?epid=1127922573&hash=item461b53e8d4:g:TMcAAOSwEnlZ4F9z

This is the one I have. I've been using it for 4 years with no problems. We only have one 100 watt panel though. You may need something with higher amperage for two panels. I'm not an electrical guy. A friend set up our system for us.

There are other dual controllers at eBay. I haven't checked Amazon.

Good luck with your install.

Joe

That's fine for what he is trying to do and can be used with series wired panels. Be advised PWM controllers can make for some nasty radio noise sort of a motor boat sound.

[Nam]

I got 3 of these...planning on mounting on the roof soon...any tips/trick/advise?

 

https://www.amazon.com/gp/product/B00BFCNFRM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

I think there is enough space. I run the fridge all the time...not sure if it will be enough...may need a second 100Ah batt....need room for that too.

 

Nam

[Nam]

one thing I am concerning is where to find the roof support? it's aluminum...and for house, I can just use the hammer, taping to it and I can feel the roof rafter...Yes I install rooftop solar once in awhile ... but for the RV's Aluminum roof... I am clueless.

 

The other option is to drill all way thru the roof and use a big washer with thru bolt...nothing worse than having the solar panel flying off the roof

 

 

[Maineah]

What I did for my RV solar is a aluminum frame work it allows me to turn it into the sun and elevate it also it folds flat and I transport it  on the bed. Don't know what you intend to power but I get all the power I need with a single 100 watt panel it keeps both of my batteries fully charged for over night water pump ham radios lighting etc. The power cord is stranded #10 wire for power loss reasons It plugs into Anderson power pole right at the batteries or the other one at the rear.

 

[Totem]

Just had first solar panel arrive for my setup. $155 340 watt 18 volt flexible single panel; weight 3 lbs.

using a roll of 2 inch double sided 3m red backed to mount.

i want to say this is same setup tika had at one of the rallies ; zero drilling.

[thewanderlustking]

On 12/25/2021 at 2:18 PM, Maineah said:

What I did for my RV solar is a aluminum frame work it allows me to turn it into the sun and elevate it also it folds flat and I transport it  on the bed. Don't know what you intend to power but I get all the power I need with a single 100 watt panel it keeps both of my batteries fully charged for over night water pump ham radios lighting etc. The power cord is stranded #10 wire for power loss reasons It plugs into Anderson power pole right at the batteries or the other one at the rear.

 

 

I am really glad I saw this!  Good point.  I might just have to rethink reattaching my big panel and set it up like this on a plug in frame.  I have two more that can be left on the roof to maintain the batteries when sitting in the driveway.