question

jesseafuchs avatar image

1978 Airstream Argosy 30ft. 6 Questions inspired by the electrical plan.


Airstream Dream Rev1 .pdf


Hello,

My names Jesse Fuchs and I own a 30ft Airstream Argosy that I have stripped down to the bones, and I am slowly poking away at rebuilding while Covid-19 has closed my local watering hole.

It’s about the time to start planning the electrical system so I can size the wire, fuses, and disconnects. I have cruised the forums the last year and know that these are tough places for someone to drop into looking for guidance, especially if I have overlooked something important or decided to buck any of the current trends, alas, I am reaching out for help from the Victron Gurus. I apologize if something is obvious and I have missed it. Please bear with me.

I have attached the basic Electrical plan. The first thing you may notice is that, for cost reasons, I have decided to not use Victron batteries. I just cannot justify spending 12 000$ more.

This brings me to my first question.

#1 Other than connecting to the Lynx Shunt and monitoring the batteries temperatures with the Cerbo GX what am I missing?

#2 I want to simplify the system and stick with Victron so I have decided to opt out of using the Simerine monitoring system. One thing I really like about the Simerine is that it can monitor current draw of loads. Am I able to do this with the Cerbo GX or any other Victron equipment and then see a visual on the GX touch?

#3 This is more of a solar question, but I have organized the solar panels in 3 strings of 2 series panels to avoid shading issues. Should I use one MPPT 100/50 or three smaller MPPTs in parallel?

#4 I have done some very loose math and according to my load audit, for 3100w I am 100 ah short and a bit overkill on solar. I just want to avoid roof penetrations in the future so I would rather upsize. If there is a more efficient way that is glaring at anyone that I am missing? I’d love the tips.

#5 I do have a BMS 12/200 but thought that it was easier to go with the Orion 1212. If anyone needs a BMS 12/200 or it actually can be easily integrated for tow vehicle charging, please let me know.

# 6 Will there ever be a way to incorporate the Garnet seamaster levels into a Cerbo without having to utilize all of Kevin Windrems hard work?


MPPT - Solar Charge Controllercerbo gxbatterydesign
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
JohnC avatar image
JohnC answered ·

Hi @Jesseafuchs

There is one thing glaring at me in #4, the panels and mppt.

The V and A don't make sense, but let's say the 350W is ok, so a total 2100W. With 12V batts a 100/50 can handle just ~700W of that. You could string the panels 3S2P with the 100Voc limit. https://www.victronenergy.com/mppt-calculator

Frankly, your system is crying for 24V (even 48V), so that mppt could then handle ~1450W. Your Tow vehicle Orion (get the Smart model for that) would change to a 12/24. Loads that can't handle 24V you could use a 24/12 Orion (or multiples of), even a 12V buffer battery too on the 12V side.

I'd use a SmartShunt rather than the Lynx, and although the Cerbo screen is handy, I'd much rather a laptop where I can look at everything, VRM, VictronConnect, even this Community, on it too. And remain remote from the actual installation, which is nice when it's compact and in one place.

I don't use bluetooth on my setup, wires and wifi only. But that's personal preference.

Lots to chew over. Keep an open mind..



3 comments
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Hey John,

Thanks a bunch for the input. I have already had a few eye openers with just these two responses. I need to iron out a BMS as well as really decide if using cheap batteries and solar panels in the meantime is more trouble than its worth.

I wonder if I should delete this post until I have all my ducks in a row?

Depending where you are located I really like the battleborn batteries. However I'm in Canada and getting them during COVID is a problem. Also I see they now make them with heaters for cold climate. Again they didn't have heaters when I ordered my Li batteries.

My Solar is 4X320w panels running series/Parallel. (I run a 250/100 mppt) but only get 72 vdc in full sun, getting somewhere around 60-65A. I could be remembering wrong on the amps though. RV has been in hibernation since October.

I ran 4/0 cable (12ft or 3mish) from batteries to Multi. I was getting overloads with a single run of 2/0. So make sure you go heavy enough with the cable if you stay with 12v.

I stayed with 12v and only down side I saw was larger conductors. I have more ah capacity. But down side is Multi has to work harder if I load it up a lot. Most of my power drain is intermittent. like coffee in am, which seems to be the largest power drain. Heck my A/C doesn't draw as much as a coffee maker.

Check out the microair easy start. thing is incredible.

I am located in Canada too! I have had my eyes on the battleborn but COVID has not been friendly to my budget. If you ever want to share your Electrical schematic and spitball, I have tonnes of free time these days. my emails jesseafuchs at gmail.

I was also wondering if there's a Victron service where i can just pay a fee for their help so I stop bothering everyone else. I usually stay away from forums at the risk of sounding like I have not done adequate research but in the short time that iv posted this question, I have had tonnes of things brought to my attention.

cleaver avatar image
cleaver answered ·

I think I may help with a couple answers.

#2 - the cerbo monitors all combined loads (data from shunt) I have the BVM-712 but it should still get info from the lynx.

#3 - go with one mppt. Space saving is important. And I have spoke to a few guys and have had intermittent issues with multiple in RV's. Never go into details but I went with one due to their advice.

#6 - If your that far into upgrading get KUS boat sensors. very easy to install and work right out of the box. If you have a odd ball tank shape, its easy to custom configure. I just got done my 3 tanks and calibrated easy. Keep the Garnet system but the KUS sensors are Approx 100.00 usd each. I installed 3 of the stainless steel SHS/SST. They come with an easy to install ring for poly tanks.


Look into a battery protect by victron as well. It will keep you from over discharging.

And I use a DCM RBS 500A remote battery switch (controlled by the BMS incase of overcharging. Or pulling to many amps from batteries.

I put in a 400A "T" fuse between batteries and master switch. The lynx setup most likely contains them but I like a fuse right off batteries.


1 comment
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Hey,

Thank you for the detailed response. I really appreciate it. I already purchased the sealevel but was thinking about doubling up if I could find something reliableish that would jive with the cerbo. Ill look into them. Cheers