Hello gents. Long time lurker, first time poster, big fan of the site.
I've never had to work on an RV electrical system much (12v batts + shore power type thing), but I have basic, hands-on electrical knowledge. Wiring a system up from scratch tougher than modding an existing system though.
The wife and I are doing a DIY campervan build. I can handle just about all of the main work without an issue. But decyphering how some of these electrical systems work on RVs is making my mind hurt. I'm probably over-thinking it, but I am seeking guidance b/c I like to do things correctly.
No solar - we'll see how things play out with usage. Maybe next year? Who knows.
I'd like to have shore power (either 15 or 30 amps) to run a couple small items and charge 1 or 2 house batteries. I'd also like to be able to charge the house batteries off of the engine when the van is running, not plugged in.
I have a ton of device lists and diagrams from good old Google. But, again, I'm not sure what exactly is the best way to do it.
Clear as mud right?
Does anyone have some system diagrams and / or equipment recommendations? Inverter doesn't need to be over 1500w. I know I'll either need a manual switch or auto-sensing switch to isolate the vehicle electrical system. I'll need a way to charge 1-2 house batteries off of AC power. Probably an auto-transfer switch.
Someone will have a link to the Roadtrek simulator, I hope, as that will show you how it all works in a system close to what you are talking about.
You are looking at very basic, no solar, no generator, moderate engine charging.
You can make you life much simpler if you buy an inverter charger of the size you need. A 1500 inverter with a 40-60 amp charger would probably be good. If you get one with an internal automatic transfer relay, you are done with that part of the charging, just hook up AC shore power wiring in, and AC coach power out and the inv/chg will take care of it for you. You would want to be able to shut off the inverter section to save power when not in use, though, so make sure it has that feature, which is usually just a switch but might be an add on control panel.
From the engine just get an automatic charge relay (separator) and then wire to the rear with #2 or so cable to the batteries with a breaker on each of the cable (120 amps). Having a manual and/or switch override for the automatic charge relay is a nice feature (Blue Sea makes such an animal).
I agree that an inverter/charger/transfer switch is the way to go. If you get a good one, it will also have AC power protection, saving you the cost and hassle of a separate power protection unit. However, it will probably NOT have surge suppression. The best way to provide that is with a residential whole-house surge suppressor. I used one of these:
There are many different objectives which will place your electrical system in the spectrum between an easy implementation or a difficult one. A key objective which can nonlinearly sway your final implementation in cost and implementation difficulties is the 120 VAC power level needed without being connected to shore power. Inverters to supply good sine AC are reasonably inexpensive but the supporting infrastructure of a battery bank, a charging system, finger size wiring needed will dwarf the cost the inverter. See this power requirement from Whistler XP800i 800-Watt Modified Sine Wave Power Inverter
In my DIY I have Magnum 1000W and later added 300W Morningstar and primarily use the extremely efficient, fan-less 300W unit. The install 1000W primarily for 650W microwave which I have not used yet.
So, if you like Keurig, do you need this type of coffee any time of the day anywhere?, how about a freshly hand grounded coffee in a Turkish or a French press style, no battery needed, no inverter needed, just a simple LPG or butane or alcohol stove.
AC device usage will be quite low. No coffee maker, microwave, fridge or AC. Possibly a small (24") TV. Possibly a media player like a Roku.
DC-wise, 3-4 LED lights, water pump, Maxxfan (7000K)... maybe some accessories / cell phone charger. Maybe an extra DC fan.
Cooking and heating of water is all propane or just making a fire. I'm like you with coffee... presspot for at least 15yrs now. I'll be driving to 12-15 weekend outdoor events. 5 state park visits where shore power is available. And two week long road trips / year.
Will need to charge or run small electronics like a laptop, phones and a small stereo / bluetooth speaker. The sink will mainly be there to wash up quick.
So after looking around for an "all-in-one" solution, my findings are:
- Wow that's spendy
- Wow that seems like overkill
In my DIY I chose compressor fridge versus LPG one with main motivation not to be forced to level the van on sloped campsites. My van has no LPG so decision for a compressor fridge was easy. Modern LPG fridges are more immune to unlevel working conditions but specs are still vague, for example - if you fill comfortable the fridge should be OK, unfortunately the damage is accumulative.
Compressor fridges are completely immune to level.
In the recent trip the 85l Isotherm fridge, LEDs, PC/TV consumed 12-15 Ah overnight, in sunny condition the energy was replenished by noon time with my 300W of solar panels.
Even with LPG on board, compressor fridge has advantages and it make sense to think through it.
If you want low cost, $105 for a power center/charger: https://www.amazon.com/WFCO-WF-8735-...ower+Center+rv
Break the tabs on the electrical outlets to be run on an inverter and wire one to shore and one to a inverter.
Install a battery isolator to the second battery $65: https://www.amazon.com/WirthCo-20092...octor+isolator
Buy the largest cheap inverter in your price range and run it with the engine running during high usage so you don't have to carry a bunch of batteries.
Or spend thousand$ on nice system with high end marine components.
Yes, I thought about a very simple setup to begin. My vehicle does have the heavy-duty alternator and the starting battery is located under a seat so the power runs are very easy.
House Batts = 2 x 85ah wired in parallel -> battery isolator like the WirthCo 150amp. Add a 600watt inverter. Then if I'm at a camp ground, just plug into 15amps and run a power strip only off of it.
It would be **nice** though to do things a little more professional. But maybe I just need to take baby steps. No doubt a guy pays either way.
AC device usage will be quite low. No coffee maker, microwave, fridge or AC. Possibly a small (24") TV. Possibly a media player like a Roku.
DC-wise, 3-4 LED lights, water pump, Maxxfan (7000K)... maybe some accessories / cell phone charger. Maybe an extra DC fan.
Cooking and heating of water is all propane or just making a fire. I'm like you with coffee... presspot for at least 15yrs now. I'll be driving to 12-15 weekend outdoor events. 5 state park visits where shore power is available. And two week long road trips / year.
Will need to charge or run small electronics like a laptop, phones and a small stereo / bluetooth speaker. The sink will mainly be there to wash up quick.
So after looking around for an "all-in-one" solution, my findings are:
- Wow that's spendy
- Wow that seems like overkill
Go Power! GP-IC2000
AIMS Power PICOGLF15W12V120VR
I guess you need to decide on what you really need. The units you show are pure sine wave, which are nice but more expensive. Do you really need the 1500 watts originally mentioned or will less be OK. You wanted automatic switching and engine charging.
If you get all your charging of devices to 12v, it will reduce the size and quality needs of your inverter.
If low cost is the major concern, what Mojoman says will work, although I personally don't like the inverter and shore power on the same outlet, and would just mount the inverter in a place where you can easily access the GFCI outlets built into it. If $500 is too much and an inverter charger of that amount is too much, your options get very limited.
You know, it might suit you better to have a number of small inverters, in various places, for the items that will need them. In reality, you really wouldn't need many or very large if you go for 12v on the chargers, music player, TV, etc. That way you could just unplug the 110v device and plug it into the inverter as needed, so no transfer switch and the shore wiring would just come in and go to the outlets and charger. Under 300w inverters don't cost much, and will usually come with a GFCI output which is a good idea to have anyway.
1. 30amp Inlet -> service panel -> 2 x 15a circuits.
2. Single 100aH house battery -> 12v fuse block (BlueSea).
3. 10a batt charger (NOCO Genius) off of one of the shore circuits.
3. Tie the house battery to the starter battery with a WirthCo 150amp batt doctor.
4. Hook up an inverter of acceptable size to the house battery. Put it in a central location.
See how it goes. Maybe by the fall I'll be kicking myself, but at least it will be easy to change.
1. 30amp Inlet -> service panel -> 2 x 15a circuits.
2. Single 100aH house battery -> 12v fuse block (BlueSea).
3. 10a batt charger (NOCO Genius) off of one of the shore circuits.
3. Tie the house battery to the starter battery with a WirthCo 150amp batt doctor.
4. Hook up an inverter of acceptable size to the house battery. Put it in a central location.
See how it goes. Maybe by the fall I'll be kicking myself, but at least it will be easy to change.
Planning for the end point often can reduce the total cost, replacing a component with a better one can be more expensive than starting with a good base from the get go. I would consider:
Re 1. Smartplug for 30A in, if you have a hitch it is easy mount - see pictures.
Re 2. If mounted inside consider AGM
Re 3. I would not use Noco, had one, research reviews. Invest a little and go with CTEC D250S to accommodate connection to alternator, and potentially future addition of solar panels. For more umf you can add later the CTEC Smartpass. For shore power charging you could use https://www.amazon.com/CTEK-56-674-A.../dp/B0045F3SGY or newer converter from Boondocker BD 1235C (35 Amp 4-Stage Converter/Charger)
Re 4. Wirth 150A is just a CB, it is better to use a smart disconnect or DC > DC charger like CTEC D250S
Re 5. Consider Morningstar 300W, one of the best small units on the market.
The $105 AC/DC power panel I linked already has a 35amp DC 3 stage battery charger and DC converter.
For a low-cost system, a converter is a better choice than inverter/charger combo which automatically forces the design to a high-power inverter because only high power inverters provide battery charging capability. Any size inverter can be added to a converter system.
As you pointing out most converters have built in AC/DC panels. Converters in the past were simple 12 VDC power supplies with unintelligent charging often boiling batteries to dry, todays inverters are often multistage chargers.
"Planning for the end point" - I don't know the endpoint so I'm planning for this season's schedule and weekly use. I will say that I will never have 200watts of panels on the roof of this van. Not enough room, and it is cost prohibitive for my meager needs while unplugged.
AGM - Yes, absolutely going to happen.
"Wirth 150A is just a CB" - Please elaborate on this when you have a sec
FYI - After thinking about a specific weekly need, I chose to wire a 30a breaker box -> 2x15a circuits. The $105 panel wasn't going to work for this.
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"Wirth 150A is just a CB" - Please elaborate on this when you have a sec
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I was not familiar with the Wirth 150A so I searched and a CB came out, can’t repeat the same results so indeed it is an isolator, sorry. The spec is a little vague so I hope it will work with your AGM battery.
I was not familiar with the Wirth 150A so I searched and a CB came out, can’t repeat the same results so indeed it is an isolator, sorry. The spec is a little vague so I hope it will work with your AGM battery.
Best of luck,
George.
The Wirth 150A aka Battery Doctor is a very popular isolator.
It is a modern design with uptodate circuit technology.
Many users install it on boats as well because it is waterproof.
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