Starting point for cheapskate electrical system?

[Gsand31415]

Boy, there are a lot of complicated schematics out there. Can someone point me to a simple 12v one with relatively inexpensive components?
Load:
Maxxair fan
On-demand pump for simple 5 gal water system
Phone chargers
A few small task LED lamps (if we stay up after dark, we tend to be outside)
A small inverter so I'm able to charge a laptop when I'm not on shore power
Battery:
Probably a 100 ah AGM, maybe expanding to a 2nd at some point
Charging systems:
Something like a Renogy 100 watt solar kit, with room to expand to no more than 300 watt total
Charging from shore power
Charging from alternator while driving

I'm familiar with shore power wire sizing from designing and building my house, garage, and workshop, I know 12v load wire sizing and fusing from my boat, but charging systems are new to me.

Where I really need help is selecting inexpensive components and getting the charging system(s) to work well together. I would appreciate suggestions helping me find schematics on this forum that are attuned to my very basic needs.

 

[BrennWagon]

That’s a whole can of worms The easiest and cheapest setup is to run a battery isolator you charge off of your alternator. Adding solar and shore power complicates things significantly and will require different controllers, so decide what your final system will consist of before you start buying components

 

[dbuzz77]

I have a fairly simple system powering your stuff plus a microwave and a fridge so i have a 220ah battery with a 3000w xantrex inverter and a progressive dynamics 80a converter. i have a 4/0 cable from the truck battery with a switch to disconnect when on shore power. you might go with smaller inverter or converter for less load.

 

[autostaretx]

Here's mine ... $350 for 200 watt solar, not counting cost of existing 67 AH (yes, too small) battery, $99 (then) shore-powered charger, $99 1000 watt inverter (in 2006).

Do I really need solar

This helps make explicit an underlying theme of this thread: In the above example, we have lots of driving and lithium batteries. As stated, solar has little value in this scenario. You would need a very large array to make much difference, and you don't really need it anyway. Lithium...

sprinter-source.com

Adequate to power a 600 watt microwave plus Engel 40 liter fridge.
--dick
p.s. link has parts list with prices, wiring diagram, installation photos
p.p.s. agreeing with Vanski's comment ... i "chose" my components (heck, i bought the battery, shore-charger and inverter in 2006) with the full acceptance that i may (or would) be changing them out or upgrading as i gained experience. Battery size was chosen in part for "liftability" ... i knew i'd be taking it in and out of the Sprinter as we flipped between "camping" and "full cargo".
Different strokes for different folks.

 

[vanski]

imo.. the real question isn't what is the cheapest install... but what is the cheapest, and most trouble free, install over a five+ year time period.

so what's the most expensive component of most camper electric systems??? usually the batteries. and what are the components that many people need to replace most often.. the batteries... why do the batteries need to be replaced.. because they suffered from sulfation.. case in point, i recently put in a system for someone replacing 2x Northstar sms agm480 batteries. These batteries are $800+tax+shipping each. They are some of the best AGM batteries on the market. But, if you sulfate them badly, game over. He sulfated them in 2 months of ownership!!! So, you either need to implement a system which doesn't allow the batteries to sulfate.. that's a big conversation. or, you install batteries that can be revitalized if they do sulfate.. or batteries which don't really sulfate such as Lithium.

Lifeline AGM batteries are the only AGM battery to my knowledge which have a realistic ability to be revitalized to a reasonable capacity once they've been severely sulfated. they use an equalization charge to do this.. you push the batteries up to 15.8v-16.4v for 8-10 hours. taking this a step further there are different solar charge controllers, such as Victron which is my favorite for a variety reasons, which can supply an qualization charge. This allows this ability without an expensive charger outside the rig. The Victron CCs can even have an automated monthly equalization charge setting applied. i'm personally a big fan of this capability.

so, i understand I didn't answer your question but folks really need to see the forest through the trees as it relates to cost of the system. not to mention the pain in the butt when things start failing when you really need them most, which is exactly when they will fail; been there!

google Will Prowse and watch some of his videos. He breaks DIY systems for beginners. He definitely has a focus on LFP (Lithium) systems for the most part, but he understands his audience are mostly budget buyers.

 

[Wrinkledpants]

Boy, there are a lot of complicated schematics out there. Can someone point me to a simple 12v one with relatively inexpensive components?
Load:
Maxxair fan
On-demand pump for simple 5 gal water system
Phone chargers
A few small task LED lamps (if we stay up after dark, we tend to be outside)
A small inverter so I'm able to charge a laptop when I'm not on shore power
Battery:
Probably a 100 ah AGM, maybe expanding to a 2nd at some point
Charging systems:
Something like a Renogy 100 watt solar kit, with room to expand to no more than 300 watt total
Charging from shore power
Charging from alternator while driving

I'm familiar with shore power wire sizing from designing and building my house, garage, and workshop, I know 12v load wire sizing and fusing from my boat, but charging systems are new to me.

Where I really need help is selecting inexpensive components and getting the charging system(s) to work well together. I would appreciate suggestions helping me find schematics on this forum that are attuned to my very basic needs.

Goal zero Yeti 400 + Walmart 150W 12v inverter (to charge the yeti). Connect yeti to the inverter, inverter to the cig plug under the cup holder. Charges automatically when you drive. Buy any sized portable solar panel you'd like, but we never needed it. We ran this way for a year. Had both our max fans wired to a single 12v plug that was powered by the Yeti.

Plus, resale is great if you go to sell this for a full electrical system.

 

[Ulter]

Golf cart batteries from Costco, battery isolator to charge from alternator, Samlex/AIMS/Renogy or equivalent Chinese inverter/charger on Amazon, residential 60 cell solar panel (can find for $.50/Watt), $15 PWM solar charge controller on Amazon. That’s the cheapest system.

 

[marklg]

Golf cart batteries from Costco, battery isolator to charge from alternator, Samlex/AIMS/Renogy or equivalent Chinese inverter/charger on Amazon, residential 60 cell solar panel (can find for $.50/Watt), $15 PWM solar charge controller on Amazon. That’s the cheapest system.

Won't a 60 cell solar panel have too much voltage for a 12V PWM controller with 12V batteries? Are you suggesting a 24V system? Those inverters are harder to find.

Regards,

Mark

 

[Ulter]

Won't a 60 cell solar panel have too much voltage for a 12V PWM controller with 12V batteries? Are you suggesting a 24V system? Those inverters are harder to find.

Regards,

Mark

Sorry yes too quick of a reply. $29 for an MPPT solar charge controller on Amazon.

 

[Gsand31415]

imo.. the real question isn't what is the cheapest install... but what is the cheapest, and most trouble free, install over a five+ year time period.
<snip>
google Will Prowse and watch some of his videos. He breaks DIY systems for beginners. He definitely has a focus on LFP (Lithium) systems for the most part, but he understands his audience are mostly budget buyers.

Great reply. I initially typed "inexpensive, durable" and then got overzealous in editing my post.
At first glance it looks like a good lead on Will Prowse.
Thank you so much for taking the time to reply.

 

[vanski]

Np... just trying to share my personal experience with these systems and experience working with newbies ramping up such that they don’t waste money and time not to mention having their systems fail them when they are trying to enjoy time out on the road.

have fun..

 

[autostaretx]

Sorry yes too quick of a reply. $29 for an MPPT solar charge controller on Amazon.

Could you provide a link to that cheap MPPT controller?
All of the hunting i did before my MPW purchase, and since, has always shown that MPPTs below $70 or more are usually incorrectly advertised (weasel words in the tiny print or manuals such as "acts like MPPT" (but not really)").
My plan has been to eventually replace my MPW with an MPPT if the "price-benefit" ever seemed to warrant it (i.e. if i put in different batteries or try a different panel wiring arrangement (series vs. current parallel)).

--dick

 

[sparkplug]

I'm still undecided on buying an inverter because I think it's great thing to have but I don't really know what I would use it to power (therefore I can't calculate what size inverter I would want to buy).

Most laptops require low voltages to charge (which is why the charging cables have a transformer on them) and you should be able to find a 12v charging cable for them.

That's what I did for my MacBook. There are a few options out there so be sure to check you're buying the right one, but if that's the only reason for the transformer then a 12v cable will be the less expensive option.

 

[Midwestdrifter]

This thread breaks down a high value electrical system for those with modest needs. Its probably larger than you need, but provides overhead for adding more loads later on, and should provide many years of reliable service at a decent powerpoint.

Budget Off-Grid Electrical Framework

Hey folks. A friend of mine asked for some advice on a basic electrical setup for a medium sized off-grid type vehicle. The major concerns were high value, reliable components, and Simple configuration. The components listed below have either been used/installed by myself, or have good...

sprinter-source.com

 

[pfflyer]

Boy, there are a lot of complicated schematics out there. Can someone point me to a simple 12v one with relatively inexpensive components?
Load:
Maxxair fan
On-demand pump for simple 5 gal water system
Phone chargers
A few small task LED lamps (if we stay up after dark, we tend to be outside)
A small inverter so I'm able to charge a laptop when I'm not on shore power
Battery:
Probably a 100 ah AGM, maybe expanding to a 2nd at some point
Charging systems:
Something like a Renogy 100 watt solar kit, with room to expand to no more than 300 watt total
Charging from shore power
Charging from alternator while driving

I'm familiar with shore power wire sizing from designing and building my house, garage, and workshop, I know 12v load wire sizing and fusing from my boat, but charging systems are new to me.

Where I really need help is selecting inexpensive components and getting the charging system(s) to work well together. I would appreciate suggestions helping me find schematics on this forum that are attuned to my very basic needs.

Your loads are the same as mine except I had a fringe in my van. There is not a lot of detail in The link in my signature Below but I have maybe $1000 in mine including the inverter. I think it is pretty simple even though I can power the inverter with the chassis battery or the house with a selector switch. I can charge the House battery while driving with a 7 stage charger powered by the inverter and chassis battery or simply combine the batteries with 1 switch. Shore power charging is done with the same 7 stage charger. No solar. I don’t have a fancy drawing of my system but I will dig up a hand drawn one if you are interested.

 

[Gsand31415]

I think it is pretty simple even though I can power the inverter with the chassis battery or the house with a selector switch. I can charge the House battery while driving with a 7 stage charger powered by the inverter and chassis battery or simply combine the batteries with 1 switch. Shore power charging is done with the same 7 stage charger. No solar. I don’t have a fancy drawing of my system but I will dig up a hand drawn one if you are interested.

Yes, I'm interested and would like to see the sketch and the brand of inverter/charger. Thanks in advance.

 

[Colorado_Al]

I'd recommend using an automatic switch for coupling and decoupling.
I've had the BlueSea charging relay in use for 10 years. No issues. Only $75

SI-ACR Automatic Charging Relay - 12/24V DC 120A - Blue Sea Systems

Automatically combines batteries during charging, isolates batteries when discharging and when starting engines.

www.bluesea.com

I also recommend spending a bit more to get AGM batteries. They'll last longer, are unspillable, and don't offgas.

I installed a simple marine charger that can also charge both of my battery systems, but rarely need it with the solar setup I have. It's a 20amp that was about $100 from Cabela's.

The inverter I bought is Duracell brand made by Xantrex. About $130.

You can get a good combo unit for about $350, like the Xantrex Freedom HF 1000.

Also, gear up to the largest alternator available for your model.

The MPPT charge controller I have is MorningStar SS-MPPT-15L. Was the best at the time of install. Not sure what else is available now.

It steps voltage from my 190W 36V panel down to 12V and charges 2 AGM batteries and the starting battery.

 

[45Kevin]

Here you go. I snagged this of Expedition Portal a few years ago.
Search for it. It's a good write up.
His thread has a single house schematic as well.

 

[Colorado_Al]

That's my basic setup. Instead of a solenoid, I have the BlueSea relay, that will enable the solar (and shore power) to also charge the starting battery.
Also, putting a switch between the solar charge controller and batteries is helpful, if you need to do maintenance while the sun is shining.
Charger and inverter connects to house batteries.

 

[HarryN]

Personally, I think that you are trying to charge from too many sources for a budget build electrical system.

The cost of (materials + your labor effort) to have 300 - 400 watts of panels vs 100 watts of panels is actually fairly small. Everything that you have mentioned can be powered from this amount of solar + some decent batteries. That is what I have on my own van and I use it to power tools and stuff all of the time. I build van electrical systems and all of this is powered 99% of the time just from the panels (batteries and inverter ).

The only times that I have been "power short" was when PGE shut down the local grid and I was going around to places that didn't have power and helping people cool down their home refrigerators from my van. I had to go home periodically and charge up from a 120 vac charger.

You can save yourself a lot of headache (and money) by keeping the sprinter's electrical system completely separate from the auxiliary electrical system. If you do run short on power down the road, then you can make the proper investment into expanding the charging capability from the alternator with a battery to battery charger.

You didn't mention it, but it likely won't be long before you own a 12 volt compressor refrigerator, and a system like this can also keep up with that load. They are just too convenient to not own one.

For a solar charge controller, I use the bogart SC 2030 for modest size systems. (1 kW class) It will charger your batteries when a lot of other controllers won't turn on due to poor sunlight conditions. You can just start with the SC 2030 and add on other accessories later as you feel the need.

Accurate Battery Monitor, Powerful Solar Charger & accessories - Bogart Engineering Battery Monitors

Bogart Engineering is the manufacturer of Trimetric & Pentametric brand of battery monitors & solar chargers. We're a team of engineers & scientists with experience in solar & battery technologies. If you researching batteries or solar technologies for use in your RV and have questions or need...

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_______

For solar panels, a better chose would be grape or solarland than renogy. If you buy some that are ~ 56 - 60 inches long, they can lay sideways across the top of the roof. Just put on some tall rails and go for it.

Or 3 of these might also work for you:

180W 12V Monocrystalline Solar Panel

NewPowa 180W Mono Solar Panel is commonly paired with RV, marine, camping, traffic signals, and various off-grid applications. Top branded,2 years warranty,Free Shipping!

www.newpowa.com