Need help... Beginner camper electrical setup

[AlexW]

I am in the beginning stages of building a cabover camper for my truck bed. I may be asking questions about that later but I am here because I need some advice on what kind of electrical setup I need for my rig...My wife and I live in Alaska and love to travel around the state to the different camp sites. 

Basically I want enough power where my wife and I could charge our cell phones and maybe a computer for watching movies when the weather is bad. For my rig I want to have 2-3 110 outlets. Since we mostly go to campsites with power(not all the time), I want the ability to plug into the power at the camp sites and charge my battery bank. Im thinking 2 deep cycle batteries is all I have room for, but thats why I'm asking now because I need more then I need to make more room in my plans. 

Bottom line up front: For you seasoned electricians out there, please tell this newby what equipment I need to make that happen. Once I get told all the materials then I can go from there. 

Thanks!

Alex

 

[John61CT]

You haven't mentioned anything that actually needs 110v on the load side, you'll save a lot both up front and for efficiency if you stick to DC (12V) only.

You'll need a strong & intelligent AC charger. If you do need an inverter, some include the charger.

Staying away from shore 110v and really using your power more than a day or two at a time increases your need for a bigger bank. Solar may help a little, or carry a generator. Or drive a few hours every day, charging fast from idling requires custom gear and wears out the truck.

Costco or Sam's Club 6v golf cart batteries are great value. Series pairs = 12V, then parallel.

Solar (and shore charging) extends bank life, don't discharge often below 50%, get as close to 100% as often as possible, at least once a week. Or replace your bank more often.

Lots of options to isolate your starter from the house bank, can choose that last.

Prepare for a lot of googling, marine-oriented sailing forums are the best.

You get what you pay for wrt quality, but don't buy stuff you don't really need.

 

[SternWake]

I'd say this charger on a pair of 6v golf cart batteries in series:


http://www.bestconverter.com/9200-148-Volt-Deck-Mount_c_227.html

Most laptops have a car adapter that converts 12v dc into ~19v dc.  This saves about 10 watts over an inverter powering the AC DC transformer your laptop came with.

Here is mine:
https://www.amazon.com/Laptop-Car-C...ywords=dell+latitude+e5500+laptop+car+adapter

Been using it for 7 years.

The Ciggy plug will become an issue eventually.

This is a much higher quality 12v receptacle and plug which will be more reliable

https://www.amazon.com/Blue-Sea-Sys...=1483434186&sr=8-1&keywords=Blue+Sea+1015+12V

There are many many methods and products for charging house battery from alternator.

Here is but one. A voltage sensing solenoid.  This does not require the user tap a 12v live with ignition wire for a continuous duty solenoid.

Single sense
https://www.amazon.com/Bussmann-RB-...coding=UTF8&psc=1&refRID=DGY5BYCM13Q8X9V9NP4T

Use a 4awg or thicker cable from Alternator (+) stud to one side of that solenoid, hook the other side f solenoid to a fuse to the house battery.

https://www.amazon.com/Blue-Sea-Sys...coding=UTF8&psc=1&refRID=Y2J09RJ27TWAV7397YQE

You can ground batteries to frame, but better to run another cable back to alternator mounting bolt.

https://www.amazon.com/Blue-Sea-Sys...coding=UTF8&psc=1&refRID=Y2J09RJ27TWAV7397YQE

https://www.amazon.com/Blue-Sea-Sys...coding=UTF8&psc=1&refRID=YXBCEC4C7C9RDGGD2X44

for USB charging:
https://www.amazon.com/Blue-Sea-Sys...srs=5638639011&ie=UTF8&qid=1483434659&sr=8-13

Pass thick battery cables through floor easily with these, or use a rubber grommet to prevent chafing, which would be better from a resistance standpoint.  Fewer connections.

https://www.amazon.com/Fastronix-Pa...3434789&sr=8-2&keywords=firewall+pass+through

not so easy to make ones own cables and have them be low resistance and long lived.

This guy can make top quality  custom cables once you know the lengths and ring terminal sizes:
http://www.genuinedealz.com/custom-cables

Lots of ways to skin this cat. Shop around, explore options.

 

[John61CT]

Wow lots of great specifics there, nice!

I'd say this charger on a pair of 6v golf cart batteries in series:

http://www.bestconverter.com/9200-148-Volt-Deck-Mount_c_227.html

That looks solid. Personally even if it were more $$, I'd want to be able to be able to adjust the charging algorithm, ideally set up a few different profiles to switch between. Any suggestions along those lines?

If I got a **great** deal on a large say milspec inverter without any charging circuitry, would it make any sense (cost/efficiency wise) to use my big fancy AC charger off that?

On my portable 12v DC alt/generator idea in the other thread, it's the electronics presenting one of the biggest challenges. The above should let me run stock (cheap) internally regulated automotive alts, "clean up" the power with the big fancy inverter, and then precisely regulate the DC charge cycles with the $$ shore charger I have to buy anyway.

If there's too much loss there, I'd need to invest in fancy external regulation hardware or a $$ DC-to-DC charger to duplicate the functionality of the shore power charger.

OP, sorry if this seems a hijack, but in fact should also be relevant for you if you're going down the off-grid boondocking rabbit hole


> not so easy to make ones own cables and have them be low resistance and long lived.

Yes not easy, but for those of us who want to, any suggestions for a good HowTo and tool source? Especially a heavy-duty crimper can properly handle 2/0, 4-guage. . .

This http://www.yandina.com/Soldering.htm is one resource I've bookmarked.

for 4 gauge in short lengths, chop clamps off a well-rated one of these https://www.amazon.com/gp/aw/s/ref=is_s?k=jumper+cables+4+gauge+20+feet

what gauge is this? https://www.amazon.com/gp/product/B0017Z1TKM/

 

[speedhighway46]

Harbor Freight sells a great hydraulic crimper for around $50 that has worked flawlessly for me for all my heavy cable connections. I've had it abt 7 years.

 

[SternWake]

http://www.pbase.com/mainecruising/battery_cables

I've been considering this set of leverage crimpers.


These budget hydraulic or leverage crimpers can make Good, acceptable and poor crimps depending on how that match up to the lug and the User moving the lever. A Klutz could wind up with unacceptable results and wasted a 3 dollar ring terminal. I am not 100% satisfied with my HF hydraulic crimper. I have filed out my own dies from their smaller sizes to properly fit and make a nice crimp.



https://www.amazon.com/Crimper-Crim...=8-2-spons&keywords=iwiss+crimping+tool&psc=1

Aim for no 'ears.' on your crimps. Also don't cheap out on the thick walled ring terminals. Lots of junk that looks good. I have employed some of this junk and crimped them allowing some ears and regret it highly.
Works just fine though, for the circuits I have do so on which max out at 60 amps. If this were 100 amps I'd likely have had an issue, but would have returned the junk ring terminals and would have put more effort into proper crimps without 'ears'.



John:
http://www.magnum-dimensions.com/mobile-power-products/inverter-chargers

Powermax also has an adjustable voltage model converter, upto 120 amps, but it is manual charger, no Stages, just seeks and holds a voltage you choose. No float stage unless you turn the dial.

These are kind of a custom order. Correspond with Errin
:
http://powermaxconverters.com/contact/
Power factor corrected so less wasted power.

Not sure I would want to power a charging source from a MSW inverter long term.

 

[highdesertranger]

"If I got a **great** deal on a large say milspec inverter without any charging circuitry, would it make any sense (cost/efficiency wise) to use my big fancy AC charger off that?"

if you meant to run a battery charger off an invertor off the batteries you are trying to charge, short answer no it will not work. if it did you would have just invented a perpetual motion device. highdesertranger

 

[John61CT]

Funny

No, alternator providing DC to fuel the inverter driving the intelligent 110-to-DC charger already needed for when on shore power.

I know, the likely conversion inefficiencies feel like sacrilege.

Thanks for the crimping links!

 

[SternWake]

So at first you wanted a DC generator as you saw a 115vAC generator powering a battery charger to be wasteful.

Now you want to run a DC generator, to power an inverter, to power a hi dollar battery charger to charge the batteries? There would likely need to be another battery in between DC generator and inverter that powers the high amp high$$ charger charging the house bank.

YOur proposed DC generator could be controlled by Balmar smart voltage regulator for 3 stage charging, but how long are you going to burn fuel to charge batteries? On lead acid most would burn gas only to 80% charged and then no stages are required, just a 14.7v setpoint and the batteries will charge to 80% as fast as possible. no smart regulator needed.

With Lifepo4 you also dont need to get to 100%, in fact better not to, so again no need for stages, just control the time and maximum voltage.

By all means spend huge $$ to get a top of the line programmable charger, for when plugged into the grid but thoughts of running it off an inverter, off another battery, which is being charged by the DC generator. seems a bit whacky.

The Honda 3000 could just be used to power the high amp high $$ programmable charger.
120vac powering DC charger.

Much easier than DC generator charging dedicated buffer battery that powers inverter which then powers high$$Charger that charges house battery.



But on a generator, DC or AC, just set the voltage high for as fast as possible recharging as possible.

Unless one likes to listen and smell a small engine burning gas to do increasingly little.

 

[AlexW]

Wow thanks for all the advice so far! I am going to be looking through all the comments and try and make sense of it all for a little bit so bear with me if theres a delay in response.

 

[John61CT]

So at first you wanted a DC generator as you saw a 115vAC generator powering a battery charger to be wasteful.

Exactly what I'm referring to!

Seems optimizing for fuel efficiency and minimizing capital depreciation requires a very hefty investment up front!

So I'm trying to ask the right questions to get from where I am - ignorant and wary of wasting scarce capital - to where I want to be, savvy and plenty of money from buying/building the right infrastructure, left over for a big bank of top-notch batteries.

> Your proposed DC generator could be controlled by Balmar smart voltage regulator for 3 stage charging, but how long are you going to burn fuel to charge batteries?


An alt putting out enough power from van engine "hot idle" was the other possibility. Carting around *any* genset is a lot of hassle if it can be avoided at the expense of more frequent engine maintenance I think that might be worth it.

And when driving long distances, getting maximum charging out of the already spinning alt seems worthwhile.

If I already have a top intelligent charger and a big inverter sitting there, maybe I don't need to invest in the duplicate functionality on the Alt-to-DC side.

was my thinking.

If not, then something like this

https://www.dropbox.com/sh/vhjwqzdup36wxp1/AADf4GrHEukw2bmLUSjyWi8Za/A2Bs.pdf?dl=0

seems to make more sense, more flexible, portable to other alts / gennies or even other vehicles.


> On lead acid most would burn gas only to 80% charged and then no stages are required, just a 14.7v setpoint and the batteries will charge to 80% as fast as possible. no smart regulator needed.

> With Lifepo4 you also dont need to get to 100%, in fact better not to, so again no need for stages, just control the time and maximum voltage.


Yes, that seems to be where I'm headed, other big plus is five times the AH/kg ratio.

But then I'll have to warm them up in bitter frozen mountain boondocking?

Plus they're so dear, I think starting off with a trad golf cart set is more realistic, later start the transition with a small "experimental" lithium bank, as I can afford to expand those AH, the cheap GC set will be getting long in the tooth.

 

[SternWake]

The Sterling DC to DC alt to house battery charger is dear.

But then again so is the Balmar 3 stage voltage regulator.

http://www.defender.com/category.jsp?path=-1|328|2289948&id=2289953

I spent about 65$ to twist a dial and choose any voltage I want when driving. that includes paying 25$ for a 5 dollar part to trick my engine computer.
.
One pays a lot for automatic 3 stage regulators/converters.

Idling not moving to recharge depleted batteries, is hard on the alternator. I've no issue maxing mine out at 65mph as it stays cool, but maxing it out hot idle, and it will easily exceed 220F, and that takes a toll on it.

Buck charging a big depleted bank not moving will be hard on any alternator. If you intend on doing this, Force cold air at it with a fan and some tubing.

 

[John61CT]

Yes cooling seems critical, one reason to do custom alt with all the diodes mounted away from the heat, supposed to safely boost effective output a lot.


The "belt saver" stuff Balmar also seems a better approach to me than just spoofing a dumb alt.


I would love to DIY the charging intelligence, being an IT geek want to explore the Arduino-based stuff, full access to creating custom profiles, set-points for constant-current vs voltage-based, keep the volts right up until true 99-100%, all ideally based on accurate SoC as well as multiple temp sensors.


But spending the $ on a good intelligent multi-output DC-DC charger may be worth avoiding my diving down a huge rabbit-hole with a steep learning curve (love me a well-mixed metaphor

 

[John61CT]

The Sterling DC to DC alt to house battery charger is dear.

But then again so is the Balmar 3 stage voltage regulator.

This unit from ProMarine seems decent value, from the specs anyway, don't know their rep for quality compared to Blue Sea, Sterling and Balmar.

http://www.anchorexpress.com/promariner-proisocharge-battery-isolator-12v-23122

 

[user 37446]

SternWake wrote:

[font=Verdana, Arial, sans-serif]I'd say this charger on a pair of 6v golf cart batteries in series:[/font]


[font=Verdana, Arial, sans-serif]http://www.bestconverter.com/9200-148-Vo...c_227.html[/font]


So how is this connected up in a normal van?  I know that it replaces or is used in bigger rv's, just not sure how to wire it in between the alternator and the battery... Sorry for being kinda "dense" electrically...

 

[user 37446]

I'd say this charger on a pair of 6v golf cart batteries in series:


http://www.bestconverter.com/9200-148-Volt-Deck-Mount_c_227.html

Most laptops have a car adapter that converts 12v dc into ~19v dc.  This saves about 10 watts over an inverter powering the AC DC transformer your laptop came with.

Here is mine:
https://www.amazon.com/Laptop-Car-C...ywords=dell+latitude+e5500+laptop+car+adapter

Been using it for 7 years.

The Ciggy plug will become an issue eventually.

This is a much higher quality 12v receptacle and plug which will be more reliable

https://www.amazon.com/Blue-Sea-Sys...=1483434186&sr=8-1&keywords=Blue+Sea+1015+12V

There are many many methods and products for charging house battery from alternator.

Here is but one. A voltage sensing solenoid.  This does not require the user tap a 12v live with ignition wire for a continuous duty solenoid.

Single sense
https://www.amazon.com/Bussmann-RB-...coding=UTF8&psc=1&refRID=DGY5BYCM13Q8X9V9NP4T


SternWake - whats the difference between the link for the "unidirectional" and this same brand, slightly less expensive "bi-directional"?  Obvious its one way vs 2 ways but I don't get the diff...

[font=Arial, sans-serif]Bussmann[/font]
[font=Arial, sans-serif]Bussmann (RB-BS-1315) 100 Amp Bi-Directional Battery Separator[/font]
[font=Arial, sans-serif][size=small]5.0 out of 5 stars    3 customer reviews[/font][/size]
[font=Arial, sans-serif] [/font]

---

[font=Arial, sans-serif][size=small]Price:
$47.56 & FREE Shipping. Details[/font][/size]

• Battery separators provide a solenoid priority system for multi-battery systems
• For vehicles and boats with main and auxiliary battery systems and alternators up to 100 amps
• Separators disconnect main and auxiliary batteries from one another to protect from excessive drain
• Time-delay function prevents battery separator from reacting to temporary voltage fluctuations
• Bi-Directional

---

 

[SternWake]

A converter like the PD9245 does not go in between the alternator and house battery.  That is a 45 amp 3 stage charger with manual override that one plugs into the grid. One needs to provide  the DC to battery cables with a converter. 

As far as the voltage sensing solenoids, Uni directional means When the engine battery sees charging voltages then it closes the circuit and parallels the batteries for charging of both.  When voltage falls after engine shut down, to a certain Voltage, it then disconnects the house battery from the engine battery.

Bi directional VSsolenoids/relays parallel the batteries when EITHER battery receives charging voltages.  I do not like these when solar is involved as I personally want all the solar wattage going into depleted house battery, not sharing a portion of it with the engine battery.  Also some solar wattage, perhaps 10 to 15 watts might be consumed to hold the solenoids contacts closed.  Depends if it is a latching relay or not.

Some others would want some solar current to goto engine battery, but my personal preference would be to keep the engine starting battery always fully charged, so that it not require any solar wattage ever.  In the event it does, one can parallel the batteries easily enough via several different methods, depending on their system's layout.

These voltage sensing solenoids and relays are good for the user who does not want to tap a circuit from ther vehicle's fuse box so that the ignition triggers a continuous duty solenoid.  They certainly perform their main function of allowing the engine to start and to charge the house battery when driving.

One reason I personally  do not like VSRs is that after driving, the battery voltage, even if the house battery is no where near fully charged, can remain over the voltage threshold at which the VSR disconnects, for quite some time, keeping the batteries in parallel for a minute, or several, or perhaps a few dozen minutes after engine shutdown. If loads are quickly presented after engine shut down, the engine battery will be providing some of the juice to power those loads until the battery voltage drops to the threshold at which the VSR disconnects them.  Again, I would prefer to always keep the engine battery bursting full and the VSR can allow house loads to skim off a fraction of the engine battery's 100% charge.  This 'fraction' is obviously not enough to cause a no start situation, unless the engine battery needs replacement anyhow, but this fraction will impact the engine battery longevity to some unknown degree. perhaps it is inconseqential in the long run.  

After removing a charging source, the battery voltage will remain artificially high for quite some time.  This is referred to as surface charge, and how long it takes to dissipate can vary widely from battery to battery, and also its health, temperature, State of charge, amperage rate and voltage at which it was just being charged, and a few other factors too.  Surface charge tricks newbies into thinking their battery is getting much more charged than it really is, as voltage will remain artificially high for a period of time after they shut down the engine, making the voltmeter watcher believe the battery is much more charged than it really is.  

VSRs are easier to wire up, not needing a trigger circuit, but I would, for my own system if I wanted something automatic  (I don't), use a continuous duty 200 amp solenoid, triggered by a 12v circuit that is known to only to be live after the engine starts, so that the house battery does not contribute amps to starting the engine.

I employ a manual Rotary switch,  Blueseas 6007M, and manually connect house and engine batteries after engine starting, and manually disconnect them after engine shutdown or at least before sundown.  I have forgotten to disconnect them, without consequence.  One caveat is one cannot turn the switch to OFF while the engine is running, or it could cause a load dump and blow the diodes in the alternator.

I actually use 3 of these switches, One for switching all Dodge wiring from one battery to the other, one for switching all house loads from one battery to the other, and one to switch Solar or plug in charging sources to either battery. At the moment I only use one battery for both house and engine, so all switches are set to '2' and I rarely turn them.  But I could drop another battery into the engine compartment and hook it up in 15 seconds, and will likely do so once my current AGM battery starts getting weak in a nother couple hundred cycles.