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Combining different charging systems, Solar, House, and Engine...


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Can somebody give me a basic anatomy lesson on how these were originally wired up?  In question is my 1986 Mini Cruiser.  

 

So one thing I have noticed is that my engine battery just does NOT go flat.  It could be 6-8 months between starts, and it pops right over happily.  There is NOTHING draining the system, and I REALLY want to keep it this way!  There is some factory Toyota Camry radio in there that SHOULD be draining it down, but it doesn't work most of the time until I wiggle the bad wiring connections behind it.  When I fix this, I will likely put a switch on the memory wire to retina this feature.

 

In the engine bay there is an isolator on the firewall.  It is old and not sure of the quality or function.  I assume it charges the house battery once the engine battery is charged.  Question, would this work in reverse too and charge the engine battery if you are done charging the house battery?

 

There is some sort of (original) charger/inverter deal that I guess recharges the house battery when plugged into shore.  The age concerns me, but not enough to replace it.  In my wanderings on the internet I have seen some mentions that these might not be the best at "nicely" maintaining a house battery and that perhaps it shouldn't be left plugged into shore for months at a time.  Is there any truth or reason for concern in this?  

 

Currently, there is no house battery installed.  This is where what previous morons, I mean nice owners, have done that gets weird.  I have two separate solar systems on the roof.  In the front is a single panel hooked up to a basic charge controller that seems to only supply USB charger ports.  I need to investigate further, but I don't think it is attached to anything else in the house.  Pointless.  Next is a very expensive system with two panels connected to a nice charge controller and some outrageously priced battery.  This is sitting in the closet wasting valuable space in a modified rolling toolbox.  It appears that the inverter portion is missing.  So currently the solar panels just charge an unused and unconnected battery.  

 

I need to look at that system again and determine why that battery is so expensive and make sure it isn't a lithium battery...  The price tag I remember was something like $800 just for that battery!!!  I suspect if it is a lithium battery, then how I deal with it is likely to change?  I will go take a look at this tonight.

 

Anyways, I want to stuff this battery into the house box and reconfigure the solar system to connect into this and charge this.  And to have this battery power up the house.  I am not sure where to start, this is unfamiliar territory to me.  Even the whole "operation" of the rv electrical systems under normal circumstances.  

 

I guess the best starting point is how does the original charge controller inverter function and where would I hook a solar system into this???  

 

And does it matter that I have 2 panels on one sort and another one?  I want to just utilize all three into one system.  

 

I want to get some rough ideas and direction so I can then actually know WAHT to research.  I have to replace the battery box vent as it currently has a solo cup stuffed into the hole, that is now home to a nice wasp nest.  And the front solar panel got disconnected when I repaired the AC, but it was fed in through a window gasket anyways.  Dumb.  So I am going to get up on the roof in a couple days and rewire the three panels to a nice aviation type bulkhead pass through.  Once I get an idea of how I should run the wires and I know if I have a bulkhead on hand that is suitable.    

 

Ask and I will get any further details that might be useful.  I might even have the original paperwork for the inverter installed in there...  

 

     

    

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This is going to be like eating an elephant, lots of small bites.

First you need to KNOW exactly what you have. Battery type/size, charge controller, the watt ratings of all 3 panels. The $800 amount is about right for a 100ha LifePo4 battery. LifePo4 batteries are VERY fussy eaters, so the controller is very important.

The small panel to usb ports does not make a lot of sense, you couldn't charge your cell phone at night, so look for a small battery. A lawn mower size one would be right.

You may end up with writers cramps, so just go slow. You have a very good starting point, if you don't want to do crazy things like run a roof AC😁

Edited by WME
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Well if the solar is charging the battery you really don't need an isolator. Usually the engine charges the coach battery while you are driving. But if the solar is doing that it's not needed. LiPo batteries are a good bit different that lead batteries so probably the PO was using solar and a LiPo system with it's own control system. Here would be a test do the coach lights work? If so with out a standard isolator they are running on the LiPo battery. The truck battery chemistry is a good bit different as is the charging system than a LiPo so they really are not compatible.

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While your figuring out what you have, think about what you want the system to do. What are your "gotta have" loads?

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Well I did some more digging and I was wrong on the battery price...  Maybe that price was full a full system with solar panels?  I am not sure but either $799 or $899 is seriously stuck in my head.  And I had a lot more trouble finding it this time.  I had some critical bit of info or luck a couple years ago that I seem to be without now.  

 

Okay the battery is a VMAXTANKS Solar SLR125.   Seems to be a good middle of the road deep cycle AGM?  It is there and tests good, so I like the cost.  :)    

 

I don't see any branding on the solar charge controller and a search isn't finding anything that looks like it.  I am seeing some controllers that look more sophisticated for as low as $20.  I will look again and unscrew it see if there is a cable or something underneath.  It just has indicator lights, where most of even the inexpensive controllers now have some sort of at least minimal LCD screen or better.  It has inputs for what appear to be three panels.  Only one in use?  But I think that two of the panels are hooked up to it.  My picture I took kinda sucks so I need to get a better one or take some more time inspecting it.  

 

The panels, I have no clue on...  Other than the obvious, finding a table with a part number, how can I figure those out?       

 

So my feeling on the isolator and the Mini Cruiser charger thing is, why not use them if they are already there?  If I can safely utilize them with the battery above, I might as well.  The solar charge controller seems to be a bit lacking in info so I will likely upgrade that.  Especially if $20-50 can get a serious improvement.    

 

What I WANT is to be able to run my rooftop Coleman AC unit on the battery for week without plugging in.  I would be settle with a night.  And I don't want to spend too much on it.  So if somebody said hey $100, maybe 200 could get what I have to last the night, sure.  I seriously doubt that is the case.  I don't know if the Coleman can even be run off the battery, period.  If it would just take a second SLR125 battery, maybe a better charge controller, a harder sell, but yeah I would probably do it.  Beyond that, I will need a better/cheaper solution.  Or just plug into shore.  

 

I do have some leeway and justification, hurricane season in Florida.  If/when power goes out, the RV is our emergency B.O.H. lol.  If AC could be run off grid, then depending on what it would take to do so it might be justifiable to the missus.  

 

I have a backup for the backup.  I do have a small generator.  I haven't tried, but I suspect it could power the RV up with AC.  

 

And thanks for your patience guys, and LOL WME on the writers cramp, well deserved dig hehe!  If this was engine management or turbocharging the 22RE, I wouldn't need to ask no silly questions.  I could answer any others had, and in painful detail too I am sure!  Speaking of, I am going to solve the "poor fuel economy" by doing just that.  I will be putting a MegaSquirt into it for sure.  And once I am out driving it, most likely I will turbocharge it.  For me it is so easy and cheap to do, that it is hard NOT to.           

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Running an 120 volt air conditioning unit on battery power has been something people have been trying to figure out for years. No it can't be done. Figuring the the AC unit uses 12 amps which is conservative multiply that by 10 to get the 12 volt amps. You can see now that your pricey battery will last at the most a half hour because your only supposed to drain it by half to preserve it's life A Lipo battery can be drained fully but now your talking 10 times the price for equivalent amp hours. Buy yourself a generator.

Linda S

Oh and a small generator won't do. Your going to need at least 2500 watts plus possibly an AC capacitator for start up

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Well if your lucky enough to have a Coleman Power saver air conditioner , 2000 watts might work with the capacitator. Another member ran his power saver with a 2000 watt predator generator. He did buy the power saver just for that purpose  and high heat and humidity has a serious impact on the power needed to run any air conditioner.

Linda S

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Ok basic rules of things... You can do anything you want all it takes is $$$$. Leading edge technology is $$$$.

Most 2000w generators have a continuous rating of 1600w, it will run most RV ACs, BUT it won't start them. Solution is tech $$$$

There is a new thing called hybrid inverter. It combines a big battery with a small generator to run a big load. The generator runs the AC and when it restarts the battery kicks in for 30 seconds of the 40 amps needed to restart the AC. Not solar but it works.

The same inverter will work with solar. The same scenario with solar would need about 15 200w panels

Plan B is a smaller AC, your generator, and a Microair easy start 364

Plan C is new tech, a 12v roof AC 9800 btu, 4 100ah lipo batteries will run it for 8 hr

Plan D is an under seat AC 10500 btu that will run directly off your 2000w generator

12v ac...https://www.campervan-hq.com/collections/rv-air-conditioners/products/kingtec-ktd-2-12v-rv-rooftop-air-conditioner

Microair East Start...https://www.microair.net/products/easystart-364-3-ton-single-phase-soft-starter-for-air-conditioners?variant=30176048267

Underseat AC...https://www.campervan-hq.com/collections/rv-air-conditioners/products/dometic-rv-air-conditioner-cool-cat-10-500-btu

This thing is a heat pump so it will make heat down to around 30 degrees. Maybe remove your heater for the install save some space.

Not running your AC makes  your needs a lot simpler.

 

Sunwise makes smaller solar controllers with only lights, anything look familiar?...https://www.sunwize.com/product-category/power-system-parts/controllers/.

 

So we got you AC whats next?

 

 

Edited by WME
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A 7200 btu AC will run with a 2000 watt generator. So here is the deal what ever you run with a battery or generator is a factor of 10 so say you have a 10 amp 120 volt load with an AC becomes a 100 amp load from a battery so you can see where this is going.

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I can't prove it but I suspect the solar controller is a Harbor Freight one from 3-5yrs back...  It looks very familiar, but I am not finding it.  I haven't sorted out how to best post pictures here yet...  Okay I can attach below once I get them to the computer.  Of course I have been looking for my phone for the past couple hours LOL...

 

I went up on the roof.  Nothing on the solar panels but a number that looks more like a serial number.  I took some measurements.  How can I figure out what watt output these are?

 

I have the old standard Coleman AC that commonly came on these.  I remember it being the odd smaller size than most more modern units are.  I have the paperwork somewhere for it I believe.  (Well the wife does, not asking her now lol.) 

 

For now the best approach is to figure out what exactly I have, and the best way to hook it all up.  Without spending more, for the moment.  I will probably spend a few on a charge controller that has some more info though since the cost for that seems fairly minimal.    

 

I will keep digging for more info on the solar panels, I want to solve what they are first.   

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Posted (edited)

Oh it doesn't seem that I "need" this since my chassis battery doesn't seem to ever get low between starts, but is there a simple way to SAFETLY trickle or maintenance charge it off the solar panels?  Or since I don't seem to have a problem, would leaving it alone just be better?  I am contemplating a wireless battery monitor, or two even, to give me any needed heads up warnings.  They are cheap enough.      

Edited by thewanderlustking
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Plan A...https://www.amazon.com/EPEVER-Battery-Controller-Duo-Battery-Caravans/dp/B01N1ZL9EK/ref=pd_sbs_2?pd_rd_w=Y945u&pf_rd_p=1f09e623-97c8-4c74-883f-063b7295f49e&pf_rd_r=XSEBKR39K3R30P6XC3AX&pd_rd_r=c16f7c8d-9e43-4a27-a4a8-7304624e0c75&pd_rd_wg=L8XyC&pd_rd_i=B01N1ZL9EK&psc=1

Plan B...https://www.amazon.com/Dual-Battery-Smart-Isolator-DEWINNER/dp/B08JYQHTRZ/ref=asc_df_B08JYQHTRZ/?tag=hyprod-20&linkCode=df0&hvadid=475855943230&hvpos=&hvnetw=g&hvrand=7729068133236143330&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029305&hvtargid=pla-1016913459282&psc=1

Plan A charges both batteries from your solar panels. Plan B goes between house battery and truck battery, when the house battery is over 13.3 volts it charges the truck battery. When the house battery drops below 12.8v it disconnects the truck battery.

How about a Plan C? connect the "USB" solar panel to your truck battery using the simple controller you have now and buy a smarter controller for your house batteries.

The power rating for solar panel is usually a tag on the underside of the panel near where the power cords are.

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Measure the panels then look on line I would guess 100 watts or less. The controllers are directional so it shouldn't make much difference. A normal panel will output around 22 volts in direct sun, it is the controllers job to keep it within standard battery tolerance.

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Just now, Maineah said:

Measure the panels then look on line I would guess 100 watts or less. The controllers are directional so it shouldn't make much difference. A normal panel will output around 22 volts in direct sun, it is the controllers job to keep it within standard battery tolerance. Mixing batteries well average out if one is 14.5 volts and the other are less they all will generally settle to 12.5-12.8 at rest.

 

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On 4/9/2021 at 3:08 PM, thewanderlustking said:

 

There is some sort of (original) charger/inverter deal that I guess recharges the house battery when plugged into shore.  The age concerns me, but not enough to replace it.  In my wanderings on the internet I have seen some mentions that these might not be the best at "nicely" maintaining a house battery and that perhaps it shouldn't be left plugged into shore for months at a time.  Is there any truth or reason for concern in this?  

 

 

 

     

    

I also have an ‘86 Mini-Cruiser. I quickly discovered the original 110v to 12v converter was cooking my house battery. I could hear the bubbling and see the smoke/steam coming off of it. Glad I discovered that quickly. Turns out the battery was just charging off the 12v panel without any kind of controller. I think it was originally wired that way, but can’t tell.  It’s a 35yo unit so I decided to replace it, along with the rest of the electrical distribution system with an all in one panel that includes charging wizard for the battery. 
 

I went with this Progressive Dynamics product:

https://www.etrailer.com/Battery-Charger/Progressive-Dynamics/PD4135K.html
 

I got mine for around $150 in December... not sure why the price went up so much? Thanks COVID?

 

I’ve yet to replace the house battery so can’t speak to the charge wizard functionality. Waiting to pull the trigger on a new battery until I’v decided on my solar set up and overall configuration. I will say the voltage is much better and my 12v reading light with built in USB charger actually charges my phone now. Small win. 
 

 

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On 4/10/2021 at 3:35 PM, WME said:

While your figuring out what you have, think about what you want the system to do. What are your "gotta have" loads?

WME- what are some “gotta have loads” you suggest. So far I’ve got water pump, fans, lights and refrigerator on my list. Probably gonna have a separate stereo in the cabin too. 

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Loads are what you listed, minus the refer. The refer runs on 115v ac or propane. There are some 3 way units but the 12v circuit is designed to maintain cooling when the engine is running, it does not cool as good as 115v or propane.

If you go out in cool weather you need to add the heater to your loads list. They draw 3-6 amps depending on BTUs. The colder the weather the longer they run. At 30 degrees they have about a 40% duty cycle.

Fantastic or Maxx Air fans. They draw 3 amps or so on high speed, less than 1.5 amps on low. For comparison the funky 12v vent fan in the bathroom or over the stove draws about 1.25 amps.

A 1156 light bulb draws about 2.1 amps,  an LED equal draws .3 amps. How many light fixtures do you have?

A water pump  draws about 7 amps, but its very short term.

Do the math and figure how much solar and battery AH you need to NOT to have economize.

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5 years or so ago HF had a solar panel kit, total power was 45w. The panels were 12x36". and 15w ea . They were about 432sq ea.

A 50 w panel is about 550 sq in, a 100w is about 890 sq in. How big are your panels?

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I have three.  The first one is 28 1/2 x 58.   So 1653.  I was wrong and only the big one is connected into this charge controller.  I went out and looked at it just now and there is a 30w listed on it.  Hard to draw a rapid comparison to your numbers above, but sounds like this might be close to 200w?!  

 

The next two are 13 1/2 x 25.   337 1/2 x 2 =  675 .  Maybe 30w?  These were connected to the dorky charge controller with USB.  

 

Now my measurements I took several days ago and were of the whole panel and not just the solar chip area covered.   If this matters.  There wasn't a lot of dead space though.  

 

Jimiflow, I will have to look into that.  I think I actually have the paperwork on the original charger, or whatever it is....  The progressive Dynamics stuff looks like a goos solution, but a tad pricier then I wanted.  But hey I can hopefully figure out if the original charger is a problem and overcharging the battery before I destroy it.     

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Check the voltage at the batteries that's all you need to know. On a small system it is highly unlikely they are series wired so at the panels on a good bright day will yield 22 volts that by it's self is too much so you need to check the battery voltage that he panels are connected to, on a good bright day. Most of the small controllers are PWM (pulse width modulated) they charge batteries by turning on and off don't get out your stop watch though! Because batteries are resistive the voltage must be higher than resting voltage usually in the 14-13 volt range a full charged resting battery is around 12.8. A small system is a pretty simple operation so don't over think it. I have a TT with 2 batteries I made a stand that folds up to charge the batteries I can turn and elevate the panel, it is a 100 watt panel the controller is mounted on the panel not the best place but but the loss is minor it connects directly to the batteries I can go indefinitely with that setup. 

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200w for the big one sounds close enough. The other 2 may be less than 30w total. You WON'T be running your A/C from your solar. It looks like you have the beginning of a good system.

Check the isolator you have under the hood if it works, use it. If its broke replace it with the voltage sense one.  That way you arrive at your camp site with a fully charged battery. Then the solar is just topping off the battery daily usage.

Give thought to removing the small ones and sell them and the controller. Hook the usb ports to the house battery. Maybe some time in the future get another Vmax 125 AH house battery. 

A kinda sorta rule of thumb is 100w per 100AH

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Your big one is probably closer to 100 watts dependent on the age maybe 150. Yes your isolator needs to work if you want the truck to start. If your solar is working properly then it could become your jump start battery! Because my panel is steerable and I can elevate it I get max daylily out put instead of high noon with a roof mount. Reduce your loads get rid of things that make heat (light bulbs for one) replace them with LEDs plug your phone into a small inverter and your laptop if you must they are small in the 45 watt range. Forget AC and big fans. If you have to have AC buy a generator. If you are going to play with batteries make sure your system is compatible LipO batteries are not going to work on a system made for lead acid or the other way around. Mine runs on off the shelf deep cycle lead acid batteries.

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Posted (edited)
On 4/24/2021 at 1:37 PM, WME said:

Give thought to removing the small ones and sell them and the controller...

 

Why bother lol?  Even if they are kinda crappy, they are there and filling holes that removing them would make.  I can plug different wattage panels into one controller, right?  

 

Pre-post edit:  Reading through the link I posted below, with a PWM charge controller the panels are all wired in parallel.  That would likely eliminate this being a concern.  But wow I found the rabbit hole and it isn't a simple cut and dry thing...  We get into using multiple charge controllers, series, parallel, and combo wiring schemes.  Well hey, I have two charge controllers to start off at least LOL!  Maybe, I need to figure out if I can connect that second one to anything.  Also it is pretty clear that for future flexibility, wiring my panels individually up to a terminal strip, THEN out to the controllers makes the most sense.  Then I can easily reconfigure them if needed.       

 

Loads:  I am thinking of all the 12v and AC loads, minus the Coleman AC.  

 

A)  I have the 3 way refer.  To this day I have yet to prove it works though...  It is the original Dometic.  My driveway is slanted just enough to probably be the issue.  Until proven bad, it will stay.  Good tip on the weak 12v!   

 

B)  Lights...  There aren't many.  I think there are only 4 x 12v fixtures.  They are cool and vintage.  I will probably leave them and just change the bulbs out, but nothing is set in stone there.  Any left in or added, will be LED.  Okay went out and counted, there are 5 in main area that are the original fixtures.  There is what looks like a CFL fixture above table.  And two in the back (one kitchen one in bathroom).  

 

C)  Two fans, one above stove, one in bathroom.  I want to change out the bathroom fan and maybe add in a second main house fan.  The Fantastic solar fans are what I am thinking about here though.  I want something that can circulate air most of the time when it is parked and not in use or plugged in.  

 

(Does the Coleman fan run off AC or on 12v?)  

 

D) Microwave.  Looks fairly modern.  I am sure a new one would be even more energy economical.  But not something I will worry about for now.  Honestly, not sure if it will get used enough to justify upgrading at all.      

 

E)  A hot water kettle.  We are both coffee drinkers, she also likes tea.  A temp controlled kettle takes up less room and is more secure than a coffee pot.  Space is at a premium, but this is a simple multi-use luxury item.  If you factor me in the morning without coffee, a necessity.       

 

F)  TV.  So at the moment I don't have one specifically set aside to use.  Just the mount for it.  I have a couple available that might be good candidates.  By good, I mean free...  My laptop is also good enough, but the missus and I do really enjoy our movie times.  I can't see a modern flat panel taking so much power to be a huge concern.  This is one area where I would consider a serious upgrade though.  The first option are a handful of portable and rechargeable 12v TV's available on eBay.  Plenty of options under $100.  But again my laptop is portable too.  I am more likely to get a big screen (in a Mini Cruiser, 27" would be theater sized lol!) ultra bright high definition something or another.  I am not sure just how big I can get away with.   Went out and looked and 27" was in my head for a good reason.  From 19" all the way up to 27" should fit nicely where I have the real estate to mount it.   I am probably not going to worry too much about energy economics for this item.  

 

G)  Other "come and go" stuff.  Laptop.  Usually a MacBook with the 90watt charger.  If I decided to take it instead of my more energy friendly Toughbooks.  I have 12v charger/dock for that one.  A small battery charge for my RC stuff.  A couple camera battery chargers.  A Streamlight flashlight charger.  This could be put on the 12v either house or cockpit.  This is one of the few items here I would permanently mount.  Probably on the house side, as I won't leave a flashlight on it unless I am using the RV.  I am not a Youtuber, so the cameras and all that aren't going to be super intensive.  

 

H)  Water heater is dual power I believe.  Only time it would be on AC, is when plugged in to shore.

 

I)  The pump(s?).  I don't know if it even works.  I am not sure how to power up the panel.  I am guessing it is on the 12v bus?  I guess it would have to be...  

 

I have a 30 amp service, my plan is not to exceed that for sure.  The longer I can go off grid though, the better.  Realistically, anytime we are using it by choice, we are probably more likely to be plugged into shore somewhere.  If we are in a SHTF bugout situation, then some discomfort is already expected.  I am more adventurous than she is and would happily go on the road for months and boondock as much as possible.  She is more the campground type.            

 

Alright further questions and homework for me to sort out...

 

1)  I would like to be able to leave the RV plugged into shore, when at home and not in use.  Is this a good or bad idea?  If I leave it plugged in, then the house battery charging setup HAS to be figured out.

 

2)  What is the best way to figure out if the house battery is just being dumped voltage and cooked, or safely charged? 

 

3)  Struggling with this concept and my thoughts and words for this part...   And these are assumptions but not made with diagrams or further manual info in front of me.  Okay so probably the house is on the 12v bus.  Apparently, the power inverter for shore also powers up this 12v bus.  (I need to go experiment and try this one out I guess.)  I could pretty easily solve the charging issue with a simple 12v (if they exist) or AC trickle charger.  But how would I keep the 12v buss from charging and cooking the battery???  Is this a simple matter of diode protecting the battery?  My brain says that would have to be a nasty big diode capable of handling the whole 12v load...  Is there a better/simpler/yet cheap way to do this?  Or is this only doable with a more modern power inverter/charger?  

 

4)  The isolator in the engine bay.  This question I have asked before, but the information seems to be contradicting, or I am simply confused.  Does this isolator let the solar (or 12v buss) to recharge the engine battery?   

 

5)  For that matter, how do I hook the solar up to the house?  Do I simply attach the 12v output from the solar charge controller to the house 12v?  If so, this explains possibly why the solar getup didn't have an inverter hooked up to it...  

 

I have been trying to hunt for a good site that goes into clear details on all this.  This one seems fair.  But they want you to pay for wiring diagrams and I am not finding even basic readable ones available to get a starting point.  While some of my questions are very specific to our Toyotas, I suspect most are more basic and that a good resource would let me find most of these answers.  I am getting a clearer picture as I read through that information, but it isn't answering any of the above for me, yet.  

 

Ironically as I am writing this, the doorbell rings.  Dude complements me on the RV, and is actually from US Solar and setting up appointments for house installs!  Too funny.   

 

Anyways, I am still at the point of figuring this all out and just trying to hook up everything I already have together first.  There are some low cost charge controllers that seem to give more information like input, output, and battery capacity.  I would be okay potentially "wasting" $30-50 on one of these as I am sure it would be an upgrade to what I have.  But any more than that, and I need a really clear idea on what I want and am getting.  If I need to spend over $100 on this, I am more interested in a full system type of solution than just a monitor and controller.   I am okay with the $30-50 to just get the system online (as is) for now.

 

I know I am all over the place and this is a lot of questions and information...  I am just trying to narrow it down.  I have spent a few hours actually now reading various articles on the site above.  Seems even the experts have almost as many unanswered questions as I do.  Hopefully I can at least get a SOLID idea how my own Mini Cruiser system works and start there.   

 

EDIT:  I forgot one VERY IMPORTANT item.  Out on the road I will likely have two dual Milwaukee M12 + M18 battery chargers.  My impact gun, work light, and all my other electric tools are all Milwaukee.  I even have a nice M12 air compressor  that while it takes a bit, will air my dually tires up to 50psi.     

 

            

   

Edited by thewanderlustking
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Long topic. You can store far more energy in a 20 LP propane tank than 10 batteries, anything that requires heat needs to run on propane fridge tea kettle water heater. Ok the hand tools have some hefty batteries so a lot depends on use, inverters are less than 100% efficient so what you take out you have to put back in. If you are going to spend a lot of time away from power you need to reduce the electrical loads. Again it is the 10 factor 120 volt items plugged in draw 1 10th the power they would running on 12 volts from an inverter. You will not overload a 30 circuit the plug is a TT30P it will only fit in a TT30R socket they are rate 30 amp max. If you trip the breaker you have some serious issues with trying to take the entire house with you to go camping. As far as controllers they need to match the solar output you only need one, in a small system even with 3 panels they well be parallel wired meaning they only need a single controller to feed the batteries that will also be parallel wired you do not need one for every battery. When in doubt buy a hefty controller more that you real need it does not care it works just the same on a small system.

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Writers cramp fer sure.😁

 

We need to know exactly what you have...both controllers and all 3 panels. You may have to flip them over to find the label. Use a little inspection mirror to see if the tags are still there first.  You told us about the battery

Thoughts... Keep the fixtures change the bulbs. A lot of smaller TVs run off a wall adapter that puts out 12-24 volts DC. Computers the same. You would run an inverter and plug in the wall wart to run things. Each step wastes power.  They make adjustable DC to DC converters. You do 12v and it supplies what ever DC voltage you you need usually in the 12-24v range... https://www.ebay.com/itm/192032921916?epid=2074479052&hash=item2cb60dd93c:g:62IAAOSwImRYMgDy

I posted a voltage sensing isolator that will allow the solar panels to keep the truck battery charged.

Boil water on the stove for coffee. Use a french press or an Aeropress.

Why all the power tools? You going to build a log cabin or something?

A regular fantastic fan will run off your existing solar panels. Really need to know watts of panels.

Coleman fan runs off AC only.

A micro wave will draw 100 amps from your battery. So it will run about 45 min. Then how to you charge them up for the rest of the night? 200w of solar will take 7+ hours to recharge the batteries after 30 min of microwave.. Use a small portable BBQ to cook.

Plugging the RV in while home is OK. IF IF you have a modern converter. OR you can use a simple timer to keep from cooking the battery with the old converter. 30 min a day would do it.

Solar panel into controller, controller output to battery. The inverter connects directly to the battery (with BIG cables, like #2). Output from inverter goes to extension cord and you plug in what ever. OR $$$ get an inverter that has a built in auto transfer switch. Then you can wire it so that it will power all the AC  outlets. Something like this is very useful in you proposed situtation...https://www.ebay.com/itm/353425175224?hash=item5249c832b8:g:f1gAAOSw1ele~v-s

 

Think lite, weight kills MPG and makes hills so LOOONG

 

 

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Okay I REALLY REALLY need to rethink how I look at power then.  I believe I have a 20 LP tank.  The stove and fridge defiantly run off of it, and I see both ac and gas lines going to the water heater.  I can't immediately see how to change it from one to the other.  It is old (the LP tank) and I wasn't really confident with it.  But I just took a look at it and see that it still has 3/4 tank!  So it hasn't leaked a bit in 2-3 years.  Also I have a built in LP space heater under the fridge.  I forgot about that or didn't even realize it was there.       

 

I might just save the microwave and electric kettle for when I am plugged into power then.  I can possibly do away with both, but the microwave sits above the fridge in a spot not really usable for much else, and neither weigh a whole lot.  I have a Snow Peak Titanium french press, and an Aeropress.  The Snow Peak you can even heat it up directly on the stove.  But a potentially better option for two people, is a Melita cone pour over setup.  Also weighs nothing, but makes two cups quickly.  

 

Tools, I won't go too far into that other than to mention, again, I am a mechanic.  Most of my road trips have had some sort of catastrophic incident that has stranded me in many a cool and strange place.  Without a breakdown, it doesn't feel like a real adventure.  I once did an emergency r&r and rebuild on a transmission in the Moab desert.  So in short, I am going to be prepared.  And have enough tools to be comfortable doing any reasonable repairs. 

 

1 hour ago, WME said:

I posted a voltage sensing isolator that will allow the solar panels to keep the truck battery charged.

        

I had missed that somehow (too busy writing perhaps -=cough=-).  I went back and found that, and studied your new links too.   I will pick up one of those, and likely a few of the other items you posted too.  All of them are reasonably priced, and excellent solutions!  I have no issues opening anything up that can run off DC power and hacking it to do so with that adjustable regulator.  I use smaller ones in many of my RC projects.  

 

Okay good tip on where to find the power info for the solar panels.  I will try a mirror or my borescope next time I get up on the roof.  And pull those controllers off and look at the backsides.  In fact, I am going to devote a few hours sometime shortly to sorting out how to power up the final systems, checking them, figuring out what is installed where, panel outputs, determining if the water pump works and the tank gauges, if the hot water heater works, the space heater, and finally get some leveling blocks to finally verify my fridge works.

 

I need to comb through this with a DVOM and a notepad.  I finally feel like I have enough background knowledge to get a decent sense for how it is all laid out.  And to know what to look for.

 

Keeping the weight down is important.  MPG supposedly sucks to begin with, and I have heard the complaints about the power.  Anyone know what a baseline/estimated MPG is for the Mini Cruiser???  Curious about the MPG, as I plan on addressing that.  I haven't felt any lack of power issues yet, but Florida is flat and I haven't driven it very far.  Both MPG and power will be addressed with some serious engine management upgrades, and eventually a turbo.  

 

Googling it, I am seeing an average of 14-16 mpg, but so far haven't found much mention of the the Mini Cruiser.  This is for the Dolphin.  Close, probably close enough?  I am seeing a handful of 20mpg estimates when lightly loaded.  The engine management in these is very outdated and horrible.  I have been through it and see a LOT of places where I can improve on it.  If I wasn't fighting aerodynamics and the weight of the house, I feel I could get this up to 30-36mpg.  That is pulling out ALL the stops including a computer controlled alternator.  Realistically, I feel I can hit 24-26mpg.  If I can get it at 20mpg loaded up, I will be happy.  Oddly, when I look for 22RE MPG, the numbers only go up slightly to about 15-18 on the pickups and 4 runners.  Doesn't seem like weight and drag hit as hard as I would expect them too.  

 

Anyways, tangent...  I won't go deep on the details here, save that for the build thread.      

 

     

 

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Tools yes, but power tools? DVOM YES.

Factory installed water heaters with an electric heater usually have a switch some where to turn the electric element on/off. Owner install units may just have a thermostat, you turn them on by plugging them in.

20 mpg is unlikely, even with a MS efi mod. Its all HP, aero, weight  and gears. You have a way overloaded Toyota pickup. Speed really kills MPG most travel at 55-60 mph . Example in a perfectly tuned rv, 55 would give you 15mpg, at 60 you get 13 and at 70 you get 10.

Basic wiring...https://www.rv-insight.com/RV-Electricity.html

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On 4/30/2021 at 1:27 PM, WME said:

Tools yes, but power tools? DVOM YES.

 

Sadly at only 46, I have fairly bad arthritis in my hands.  Years of wrenching.  I can alleviate most of that by utilizing power tools.  But if I have to do anything intense with hand tools for more than an hour or two, I am hurting for 2-3 days after.  It puts me in a crap mood and driving any distance after that would potentially end in divorce...  Thank goodness typing doesn't seem to bother them...  🙃   

 

WME I am going to quote and respond to the MPG thing over in my build thread!  

 

Super duper cool!  That RV Electricity Insight link is pretty awesome!  I have that open and am going to go give it a good read the next couple days before I type too much more!  

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  • 1 month later...

I have been watching every youtube Toyota RV video tour I can find.  Surprisingly, there are a decent amount of them!  And while most of these are setup for full-time living, I didn't see a single one with a microwave.  In fact, one person commented that most microwave food falls into the "unhealthy" category.  Something to think about.  And I also noticed that space above the fridge being utilized for a larger kitchen counter area.  Mine might be too high up to be really usable though, as the heater is underneath it.  For now a problem I can solve by leaving it there, but I suspect it is going to be dead weight.  

 

The solar panels seem to actually be glued to the roof.  The big rear one at least.  It appears to be sitting on some sort of rubber standoff washers, and glued to them.  Minimal roof to get a mirror underneath.  Small problems lol.  

 

Anyways, I finally have enough of background picture of how a system can be setup. how mine actually is, and some ideas on improvements.  When I do the roof repairs here shortly, I am probably going to change up how the panels are mounted.  They will likely need to be removed to make the repairs anyways.  

 

I have given it a serious amount of thought though.  For now, I am going to primarily focus on the shore power configuration.  While I would love to have the perfect off grid system, it probably will mostly be plugged in at some RV park destination, or at the house here.  I am going to focus on fixing it so that it doesn't fry the house battery to leave it plugged in for longer periods.

 

Staring at the various options and I think the easies way to do this is to isolate the 12v system from the shore power and inverter.  It seems the house battery gets cooked by the 12v bus.  If the power inverter isn't connected to the 12v system, and isn't directly charging the house battery, problem solved.  I can use some sort of smart battery tender/charger and connect that to the shore power.  Connect the battery to the 12v side and let the solar charger serve as the main battery charger.  

 

Anyways, I need to find the schematics and manuals for the house system, and dive into that directly with a DVOM to see for sure.  But I am getting a pretty clear picture now of what is going on in there and when I deep dive into the remodel I will know how to clean everything up.             

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I've been using a smart charger to keep my house battery charged up and it works well. I disconnected the old outdated system because it would both overcharge deep cycle batteries as well as mess up all of the led lighting I've installed. It's a NOCO 3.5 A and it came with a pigtail that I could install right to the power distribution block. I take it out for other batteries when not in use. Works well.

IMG_20200601_103903035.jpg

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KISS, just update your converter to a modern 3 or 4 stage converter.

https://www.bestconverter.com/Upgrade-Kits-for-MagnetekParallax_c_64.html

Solar panels are black and in full sun, they get HOT cooling air on the under side is very important

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Matt B, that is exactly along the lines of what I am thinking.  My 12v lighting will get the LED bulb upgrades, and probably just be powered off the 12v house battery itself.  This provides plenty of natural filtering using the battery like a capacitor.  I could probably find a more inexpensive option than the Noco, but it is a GOOD little charger for sure.  A quick look finds a lot of decent looking options in the $20-30 range.  Including a Noco maintainer.  The thing I will need to figure out, is if a simple maintainer kinda smart charger will be enough to balance whatever the 12v lights use up.  I like WME's Plan B above.   

 

On 4/20/2021 at 11:11 AM, WME said:

Plan B goes between house battery and truck battery, when the house battery is over 13.3 volts it charges the truck battery. When the house battery drops below 12.8v it disconnects the truck battery.

    

 

WME, I still have the pricetag to consider...  Until everything else is done and this is actually getting USED, I don't want to put a lot into the electrical charging system (or anything that doesn't get it driving down the road) and want to utilize as much of what I already have as possible.  With that said, I also want do enough to protect what I already have in there.  It is a very nice battery, and at least a fair solar system.  

 

The big panel doesn't have much air gap under it for sure.  Maybe 1/4".  Just enough that leaves and stuff gets underneath it, and is really hard to clean out.    I think the other two are mounted higher up.  But they are also bolted to the roof with holes drilled through it.  I don't like how any of them are mounted.  It is something I will need to address the I reseal the whole roof.  

 

I really like the "idea" of being able to track and monitor the batteries, solar, and power usage.  I don't know what this idea looks like though...  I probably want a solid base system. probably a more advanced converter than what is in there, with the monitoring system either being a separate control panel tablet kinds style, or perhaps phone/tablet connectivity.  If the technology can ge separated from the core system, it usually is cheaper and easier to update down the road.  Advanced tech like that also stope working sooner than a solid base.  For instance, our converters are still going strong 40+ years later.        

 

So one thing I have to be really careful of is the realization, this is just a fancy tent with some extra amenities.  I'm not living or traveling in it full time.  While someday that could happen, it won't be in the next 10yrs at minimum.  If I spend money like it is the house, it may become my house before it is my choice to do so... ;)  It needs to be nice enough that a few days spent in it here and there are comfortable, and get her interested in the idea of possibly longer term travel in it.    

 

It also is our "bug out" vehicle and house for Florida's hurricane season.  


Still, if I spend $30 here and there on this and that piece times 10, when just spending $200 out the gate gets it all done...  But before I spend anything on this system that won't be useful in the final configuration, I need to figure out the power output from the existing solar panels.  They will be the primary battery charger as they are there and supplying free energy already.  If they are capable of doing most of the work, then the need for more expensive in-between solutions decreases.  99% of the time, it will sit in the driveway not connected to shore.  Yeah, I would like to be able to leave it plugged in so the AC could run and air circulate, but that  isn't too practical.  

 

I am going to post a separate thread on that though as it is going way off topic for this...  

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I installed a simple one like this and it has worked for me so far. If I used my RV more often I'd probably get something with Bluetooth. I determine battery charge state and condition based on voltage. I don't have any real power drains going other than a fantastic fan. 

https://www.ebay.com/itm/Dual-USB-Car-Cigarette-Lighter-Socket-Splitter-Power-Adapter-Charger-Outlet-12V-/132225301652?_trksid=p2349624.m46890.l49286

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