Adding more Solar and DC-DC charger

I'm not solar expert..... I heard from an acquaintance that purchased an extra solar panel. You may not have the room to carry one....but anyway, to supplement his roof mounted panels on those days when it's hard to get enough sun to top off the batteries, this is what he does.

He pulls the extra panel out of its storage spot and positions it on the ground, angled up and aimed properly with a home made metal frame thing, and aims it to catch the sun as it starts to come up. This gets some amps going 1st thing. He may or may not move it again, just depends, but he will wait, if needed, to re aim it for early evening to start catching the sun as it goes down, thus catching the the last of the suns energy.

It's a little expense, not a lot, you need another good panel, the wiring, and some material to make the framework to hold and aim the panel as the day progresses.

Best wishes to you.

thank you all very much for the replies , really appreciate it. Ive been doing a lot of research and i created another thread to get some feedback on my preliminary wiring diagram , but im still confused about a couple things

adam

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30286820.cfm

I'm not very knowledgeable about electrical things but I did install my own solar system so I can tell you what has worked for me for the last seven years as a full-timer that boondocks 95% of the time, mostly in the winter in southern Arizona, southern New Mexico, and southern Texas. And yes this is the set up I have on my fifth wheel and not a truck camper. But I'm in the process of selling my fifth wheel and buying a truck camper so this thread interests me. And this solar system is approximately what it takes for me to be comfortable as a long-term boondocker no matter what RV I'm in.

840 Watts of Kyocera solar panels, 400 amps of BattleBorn lithium iron batteries, a 60 amp MorningStar solar controller, and a 1200 watt pure sine wave inverter.

I know some people need a lot less, and some folks need a lot more but for me, this works out just right. It won't run my air conditioner of course but it runs everything else I need to run.

In the summer when the sun is directly overhead this is way more panels and batteries that I actually need. But during the winter when the sun is low and days are short, this gives me all the power I need, even after three or four days of cloudy weather. And I have enough panels that I don't have to climb up on the roof and orient the panels toward the sun, they just lay flat all the time.

As for the cold weather, yes it does get pretty cold sometimes even in the Southwest so I put my BattleBorn lithium iron batteries under my bed where they stay warm, and yes I'm safe with them under their. But I did put a smoke alarm under my bed just in case!!

Theboondork.com

I like your plan. if you have the room increasing your solar to 800 watts will definatly get you better charging even in low light and on a normal day you will be charged alot faster. One thing to concider is the type of panels your using, if you can upgrade to 24V split cell panels would highly sugest that. to give you an example of the difference in my 5th wheel I have 480 watts of 12V panels with a PWM controler and ya in the summer I never have to worry about power, but once furnace season starts I have to be very carfull and some times plug in. in the fall before say 9am it puts out nothing. In my truck camper I have a single 325 watt 24V splitt cell panel and it puts out more amps than my 5th wheel, and starts producing power when it is barley sun up. last week at 7:30am it was already putting out 0.5 amp, not a lot but it was pretty much still dark and thats is an extra 1-2 AH back in the battery before the 5th wheel even starts putting out a charge. Myself I am putting another panel on the camper to take it to 650 and a larger battery and Ill be good to go. I am also looking at the DC to DC charger for while I drive or an emergency.

I do like the idea of the DC to DC charger, some one mentioned you could buy a lot of propane, but the ultimate goal for me would be not to have to have a generator and the DC to DC would only be a emergency charging source.

with a 280 AH LFP, I am assuming your built your own? if so the only other thing I would add to this plan is another one for more capacity. not right now but later down the road if you need it.

Steve

theoldwizard1 wrote:
idling your vehicle to recharge your batteries is not the most energy efficient method.

YEP. Idling won't produce much usable charge rate because the alternator is not spinning as fast as it would while driving.
It's also a huge waste of vehicle fuel just for the purpose of trickle charging your battery.

I'd also highly recommend a Victron BMV-712 battery monitor

I have an upgraded charging system on my truck. It does very well when I'm traveling (driving)

Cable upgrade / dual alternator in my truck

DC to DC Charger in the camper

Hello Moonlitsouls.

Lets face it, going off grid is all about battery storage capability - solar panels and how to charge ones battery bank.
This is my set up,,,
Ford Truck - 2002 Ford F350 7.3 diesel
Truck was ordered with the single alternator.
Second independent Alternator - 200 amps
Twin Deka group 31 flooded deep cycle battery's hanging from the trucks frame rails. All wiring is of 1/0 gauge welding wire. (fine strand)
Lance R/V - Twin Deka group 31 flooded deep cycle battery's
Total of 4 solar panels for a whopping 470 watts of charging. The solar panels are fixed and do not move.
Also for ease of wiring, the 2 factory solar panels have one thirty amp charge controller and the 2 Kyocera panels that I added also have their own 30 amp controller
Also the Lance R/V has been totally re wired with 1/0 welding cable.
For connectors between the Truck & RV I used 175 amp Anderson Connectors
All Battery's are wired in parallel configuration with the positive wire of the R/V on battery #1 positive post and the R/V negative with on battery #4 of the negative post. This way all battery are equally in play and draw down together and charge up together.
Besides the usual R/V electrical usage, I keep an ARB compressor freezer in the back of my truck that also draws off my Battery Bank. It stays on all the time and have had this ARB in the truck for over 2 years now.
Lastly I have a 2000 watt pure sine invertor located in the R/V and is wired with 3 - double pole, double throw relays so I can take 3 120V circuits off the Lance 120 volt system and with a flick of a switch swap these circuits to the Inverter.
I can go up to 3 cloudy days with no sun and my battery bank will be in the 11.8 to 12.0 range.
My latest test was my R/V was parked in from of my house for 3 weeks with no shore power and admit to have no more than 2 cloudy/rainy days at any given time and my battery bank never ever dropped below 12.2 amps.
The best charging feature for me is that independent 200 amp alternator and its exciter circuit. I have seen over 50 amps of power going into my battery bank when driving down the road.
Yes the solar is great but with 3 stage controller limiting me to 70 percent bulk charge then 20% absorption charge then the final 10% float charge, when your battery bank is down 50 percent or so, you need something faster to charge those 4 battery's
Lithium battery's do not work for me as I do too much winter camping and if you are the owner of Lithium battery's you know what the cold does to them.
Bottom line:
Four - 115 amp Deka flooded battery's
Four - Solar panels with a total of 470 watts

Zero electrical issues.
Mike Tassinari

JimK-NY wrote:

Next I would look at the fastest way of charging. I don't know anything about Li batteries so I cannot offer specific help.

The fastest way to recharge any battery is a 75A+ power supply. This would need about 1500W of AC input power.

Look up MexicoWander's post on his Frankenstein system. Fully MANUAL (timer)? It gets most of the charge fast and then you can hook up and automatic charger to finish it off.

Will Prowse like his 75A AIMS CON120AC1224DC converter/charger.

moonlitsouls wrote:

add a 200amp high output alternator and a renogy 60 amp dc to dc charger

Don't waste your money on the high output alternator.
The Remote DC-DC charger is a good idea, but idling your vehicle to recharge your batteries is not the most energy efficient method.

Assuming you are still in the NYC area, 400 watts of solar should indeed give you a max of about 15 amps and a total of about 125 AH/day in full bright sun with no obstructions blocking your panels at any time.

A couple of months from now those outputs are going to drop in half and you will be lucky it hit a max of about 60 AH/day. If your current output is insufficient, you are not going to be able to add enough solar capacity to handle short, cloudy winter days.

I do not have the solution or even full understanding for your situation but I do have a couple of suggestions. First look at an energy audit and look at steps to conserve power. Reduce use of electrical appliances, convert to the most efficient LED lighting, avoid using an inverter and any 120 v devices. Saving on consumption is likely to work better than trying to add panels.

Next I would look at the fastest way of charging. I don't know anything about Li batteries so I cannot offer specific help.

Lastly look at the wire gauges especially for the solar to battery circuits. Typically there is a lot of waste due to use of marginal wiring.

By the time you replace the alternator, add the charge controller, and get the dc to DC charger, you could buy a heck of a lot of propane.

You don't say what sort of converter you have. It may be an idea to replace it should you choose the generator route.

Did you originally do an energy audit? If not, do so before you proceed.

Is the existing charge controller maxed out? If not, then add more panels.

I'm surprized at the lack of charging from the 400 watts of existing panels. I get 17 amps, when the batteries are hungry, from 256 watts of panels. And my panels are from 2005.

The one mistake I made was maxing out the existing charge controller.

Folks might be able to help you out more easily if you would list all the equipment you have now.