Incremental Power Solution for Van

Life on the Road Electrical: Batteries, Generators, Solar, etc...
1

Hi all

I just found this forum and have been exploring all the amazing discussions

I decided to share my plan and get feedback from all the experts out there

I have a 2020 factory built campervan, a rapido v62 and I now want to expand the power capability of the same.

The van came with a couple of 75ah deep cycle batteries, a 100w solar panel with mppt, a charger from 230v to 12v and I assume some sort of dc to dc charger to charge from alternator (unless it’s a direct connection). The van came also with a 230v Air Conditioner that I assume the previous owner used when in camps.

I have had multiple RVs in the past and just now moved into a Van. We are well used to all the luxuries of glamping and decided we needed to upgrade the power solution to cope with alll our needs/wants.

I did however decided to phase the upgrade as I don’t want to over spend if I realize what I have is actually enough. I also try to do the changes as modular as possible in a way that if I decide to change veicule again, I can just take the system with me.

So, phase 1 was already done and simply consisted of getting a “all in one” powerstation, a Fossibot F2400. Was considerably cheap (for what I get) at about 700€ and got me a 2.400w inverter, 2000w power bank, etc. I have connected the power station to the house battery so that it charges from it (from alternator/solar - also bought a battery isolator but not yet installed) and the 230v output directly to the van board so that it powers all 230v plugs when I turn the inverter of the power station on.

This was already a massive improvement as I can now use any 230v appliance I want (nespresso, toaster, mini oven, Air Con, etc). The only current limitation is that the charge is mostly done when driving through alternator at 100/110w max so it takes me like 20h to fully charge the battery.

Phase 2 is planned to be adding a 12v to 24v 15A Victron Orion converter between the house battery and power station. This should increase the charging when driving to over 400w. Would make charging 4x faster but still limited to when driving.

Phase 3 will consist of adding more solar to the roof. I plan on keeping a separate panel for the house battery maybe at 50 to 100w just to keep it charged and create a separate system of about 300w(1 or 2 panels) feeding directly to the power station. I don’t have more space in the roof as there is loads of stuff there (vents, windows, anthena, Air Com, etc)

Phase 4 (optional) may consist of adding some lithium batteries between the house battery and power station to act as an expansion of the power station. The alternator/solar can charge the battery and the battery will feed into the power station.

Now, all of the above sounds good but leaves me with multiple questions and not sure is the most effecient option (while keeping costs controlled).

Ex:

  • The power station max amperage to charge is 15A, reason why I’m getting the Victron 12v to 24v (will set it at 30v) as the trick to charge faster is increase voltage. Should I then get 24v panels also? Can they feed in directly to the power station without any switch? During the day the panels voltage would be higher then the alternator and all would be fine while during the night I assume 30v being back feed into 24v panel (VOC 41v) should cause no damage (I think…)
  • Or should I get 12v panels and feed them behind the converter (it takes 9v to 18v but I think VOC on panel may go as high as 20/21v). But again same question, can I connect the panels directly? I want to avoid an extra mppt as there is always some effeciiency lost and the power station does not need it.

But any other suggestion or thing you see wrong feel free to comment

2

Greetings & Welcome!

Be careful here, to my understanding you should never exceed the manufacturers specs for charging, this applies to volts, watts, and amps.

You can’t up your charging capabilities by playing with different voltages. Your alternator is putting out xx amps @ yy voltage period. Not all of that power is accessible, because part of it is needed to run the vehicle. The only way you can increase that power output is with a bigger alternator, or adding a second alternator.

The specs on your power station appears to be that it can charge at 1100w @ 120v AC. That translates to 92 amps @ 12vdc. The question then becomes does your current alternator have 92 amps to spare. More than likely it doesn’t. So the limiting factor is going to be your alternator.

If it was me, I’d try to replace the 75a batteries with 100a-200a deep cycle (NOT LITHIUM!!!) batteries if they’ll fit. Then charge whichever system is the larger of two from your charging sources (Alternator, Solar, Shore Power, Generator etc.) and then charge the smaller one from the larger one at the same time, with an isolator between the two, so the smaller one is only being charged when the larger one is being charged.

For solar, multiply your battery bank amps by 3 to give you watts of solar. Example: 100a battery = 300w of solar.

Realistically, you’ll need either a generator or shore power to power an air conditioner. That’s why many of us use low power swamp coolers instead of air conditioners. Most of the people claiming to run their air conditioners on battery power are actually using swamp coolers. Many people, even in homes, call their swamp coolers air conditioners.

A swamp cooler’s cooling power is accomplished via evaporation, and you need to add water to make it work. There is a newer version though, a Peltier powered heat pump, that can heat/cool the circulating water using a Peltier chip. The water is in a closed loop, so you never need to refill it. These only use about 5a @ 12vdc.

After all is said and done, many of us wouldn’t be caught dead without a fuel powered generator & and a battery charger. Even then, I choose fuel powered instead of electric powered whenever possible.

Good Luck & keep us posted!

Cheers!

"The road to success is often littered with failures." ~ Rubber Tramp


3

Thank you so much for the reply

I’m trying to share my experience here for everyone to follow

In regards to the powers station, I’m confortable with the specs, etc. I did watch load of videos, did a lot of research and have been doing some tests. I’m not an eletrician

From charging side on DC, the power station is limited to 15a, 50 or 60v (need to double check again) and 500w.

The powerstation uses the same xt90 plug for both lighter charger and solar and when it recognizes voltage around 12v it limits charging to 8a to avoid blowing any fuse inthe car. So, at 12v, all it gets is 100w charge per hour (110 when car is driving as alternator raises voltage to over 14v). So, it is common practise to do use a 12v to 24v converter as that will trick the powerstation thinking it’s solar charge and opening up the entire 15a. Of course you can only do that if you wire direcly to the house battery. The converter I plan to use increases voltage to 28v and allows to input the max amperage the power station allows (15a) charging at 28v x 15a = 420w. Yes, that means it pulls around 40a at 12v from house battery/alternator but that should be fine and below the alternator limits.

On the Air conditioner side, I know it’s like a myth to run one on DC :slight_smile: but I can say that I do run mine from the power station for about 2h and it’s a proper Air Con, a Dometic, not a swamp cooler. It was already in the van when I bought it so I just plan to keep it.
My Air Con consumes about 700w/h, hopefully less once the temperature is stabilized but even at 700w I think I can work with it.

Even if I can’t run it non-stop, I’m already happy to run it for 2h maybe at the end of the day to cool down the van so I can sleep in a confortable temperature but 1) need to recahrge back the 1.4kw the next day and 2) if I can get more then 1.4kw I could keep it running longer.

Then, from a solar prespective the current 100w panel is enough for my current house needs (tv, lights, etc), if I can squeeze in about 400w panels more, it should provide me more then the 1.4Kw needed in the summer to fully recharge the power station during the day so I can use the Air Con at night

4

Greetings!

Hmmm… Interesting… What is the output of the house charger?

Cheers!

"The road to success is often littered with failures." ~ Rubber Tramp


5

Sorry, not sure I understood your question. You mean the AC to DC charger of the house battery? 230v to 12v?

6

Charging batteries too fast will damage your batteries. IMO your lack of understanding electricity you are flirting with disaster. You need to get with a qualified AC/DC Electrician before you burn your truck up.
This message isn’t to hurt your feelings but with reading your post you don’t have a clue. Voltage is “pressure” Voltage goes up….current goes down. Good luck.
VanDweller is really good at this stuff, he could redesign your system and get you started with the basics.

1 Like
7

I don’t know how you jumped to those conclusions… it may be the fact that I don’t express myslef well since English is not my mother tongue.

I’m not an expert with eletricity but not a noob either, i did had classes and made multiple eletrical systems during my life, mostly 230v systems. None has ever burned…

Now, with 12v I’m a little more rusty and that is why I make a lot of investigation prior to any change.

As I wrote on my original post, I did do several changes so far on the van and I’m extremly happy with them. I’m sharing them here so others can maybe get some tips as sharing is caring :slight_smile: