Travel Trailer 24v LiFePo4 / Solar / Charger / Inverter system setup...

[MT59918]

sooo..

Here is the new setup I guess.

I picked up a Victron Lynx power in today. Anything I am missing?


Edit.. oops I forgot to add the Raspberry pi venus with touch LCD but that'll be an addon for later.




View attachment 40904

Wow, this is exactly what I’m looking at doing for my application, and have been trying to piece together. What are you looking at for total cost on this setup?

 

[DerpsyDoodler]

sooo..

Here is the new setup I guess.

I picked up a Victron Lynx power in today. Anything I am missing?


Edit.. oops I forgot to add the Raspberry pi venus with touch LCD but that'll be an addon for later.




View attachment 40904

Nice. I suggest replacing your solar disconnect with one of these. Do take care with the wiring. The solar panel negative wires must converge to a common negative when using these devices, otherwise they may not trip when they should. This is called a ground fault interrupt device and will completely disconnect solar arrays (positive and negative lines) in the event of a ground fault in the solar array; but, can also be manually ”opened” as a functional disconnect.

 

[CanadianEH]

Nice. I suggest replacing your solar disconnect with one of these. Do take care with the wiring. The solar panel negative wires must converge to a common negative when using these devices, otherwise they may not trip when they should. This is called a ground fault interrupt device and will completely disconnect solar arrays (positive and negative lines) in the event of a ground fault in the solar array; but, can also be manually ”opened” as a functional disconnect.

Hmmmm Never though of using that.

I was using the dual pole breaker just as a disconnect not an actual circuit breaker. Ill have to look more into this. Thanks for the tip.

Wow, this is exactly what I’m looking at doing for my application, and have been trying to piece together. What are you looking at for total cost on this setup?

I dont have everything yet.. But Ill try break it down for what my costs are.. I have been able to patiently wait and pick things up as they go on sale or buy from Kijiji / facebook market place or Amazon, or Alibaba. I also have a few of these things already in my trailer installed so I will be reusing them. So I didnt add in their cost.

Purchased so far:
Multiplus 24v 3000w = $1017CAD ( $810 USD)
Lynx Power in = $100 CAD ($80 usd)
8x 310ah Catl LiFePo4 Cells including all shipping and duty = $1170 CAD ( $938 USD)
JDB 100a 24v 8s BMS /w bluetooth module / shipping and duty paid = $75 CAD (60USD)

Need to buy: ( estimated cost based on local retail prices)
Mppt smart solar 100/50 = $400 CAD ($320 USD)
Smart Shunt 500a = $170 CAD ($136 USD)
Mega fuses total = $50 ($40 USD)
Buck converter = $39 CAD ( $32 USD)
Disconnect / gfi = $100? ( ??)
2x Qcells 400w Peak duo = $$500 CAD ( $400USD)

Already Owned from a previous small system solar install not accounted for:
Blue Sea Disconnect
Roof entry gland
Bundles of 8awg PV wire
Misc Large Gauge wires from 0/2 - 4 awg
crimp on lugs
MC4 connectors

All in all looks like Ill be sitting around $3500 CAD or approx $2800 USD not counting the stuff I had already. Which is about $500 above budget still, But I splurged on the multiplus when I found it so cheap.

Im hoping to be able to bring that total down a few hundred yet by waiting to buy a MPPT and smart shunt until on sale or such.

 

[willo]

sooo..

Here is the new setup I guess.

I picked up a Victron Lynx power in today. Anything I am missing?


Edit.. oops I forgot to add the Raspberry pi venus with touch LCD but that'll be an addon for later.




View attachment 40904

Precharge circuit! You can use a dual battery switch and a big 25 ohm resistor - make one position perform the precharge and the second is normal on. ERm, also that BMS is gonna die. The 3kw will over-run it. You can add a contactor that's driven by the BMS to take care of this. (Still needs that precharge circuit)

 

[CanadianEH]

Precharge circuit! You can use a dual battery switch and a big 25 ohm resistor - make one position perform the precharge and the second is normal on. ERm, also that BMS is gonna die. The 3kw will over-run it. You can add a contactor that's driven by the BMS to take care of this. (Still needs that precharge circuit)

I was going to crank down the inverter. To 2000.

The biggest load I'll ever use is a hair dryer.

 

[johnontheweb]

I have a 24 v system and would not go back to 12v. Most major draws, heaters, stoves, and even fans have 24v options negating the need for buck converters. Yes I have some 12 v hook ups but 24 to 12 v converters are cheap and plentiful. 24 v is the future as more power is becoming available. Check out the packaged solutions from watts24.com...smaller, cheaper, and better than comparable Victron systems. Victron is great but you pay for it and in most cases there are good enough options

 

[willo]

I was going to crank down the inverter. To 2000.

The biggest load I'll ever use is a hair dryer.

Fair enough, but you'll still want that precharge circuit.

 

[CanadianEH]

Fair enough, but you'll still want that precharge circuit.

Jdb doesn't have a higher bms with all the same functions as the 100a atm. When they do release one I'll likely upgrade to that one 150 or 200.

But I wanted to stick with Jdb (overkill). Vs Daly.


You mentioned using a blue sea 4 way selector as a disconnect as well as precharge.. Do you mind explaining further?

 

[Whinny]

Inverter Disconnect Switch with Precharge

To get the paper, click on the orange button at the top of this page. This circuit is designed as a disconnect switch that allows the user to pre-charge the inverter capacitors before turning the switch completely on. 26 June 2020 update: At...

diysolarforum.com

 

[John Frum]

I have a 24 v system and would not go back to 12v. Most major draws, heaters, stoves, and even fans have 24v options negating the need for buck converters. Yes I have some 12 v hook ups but 24 to 12 v converters are cheap and plentiful. 24 v is the future as more power is becoming available. Check out the packaged solutions from watts24.com...smaller, cheaper, and better than comparable Victron systems. Victron is great but you pay for it and in most cases there are good enough options

Cool can you point me at something roughly equivalent to a maxxair at 24 volts?
Also any suggestions for a carbon monoxide detector?
Please and thanks!

 

[CanadianEH]

Cool can you point me at something roughly equivalent to a maxxair at 24 volts?
Also any suggestions for a carbon monoxide detector?
Please and thanks!

CO detector https://www.westmarine.com/buy/fireboy-xintex--co-carbon-monoxide-detector--18023986

Not sure about the maxxair or Fantastic fan.

 

[willo]

Jdb doesn't have a higher bms with all the same functions as the 100a atm. When they do release one I'll likely upgrade to that one 150 or 200.

But I wanted to stick with Jdb (overkill). Vs Daly.


You mentioned using a blue sea 4 way selector as a disconnect as well as precharge.. Do you mind explaining further?

Here you go.

Simple Pre-Charging to avoid sparks – Burningflux.com

I'm building an automated version with my new controller, but I'll be using the manual version as a backup to my automatic one.

 

[CanadianEH]

Here you go.

Simple Pre-Charging to avoid sparks – Burningflux.com

I'm building an automated version with my new controller, but I'll be using the manual version as a backup to my automatic one.

Perfecto. Pretty sure that is the exact same blue sea switch I already own except red.

 

[willo]

Perfecto. Pretty sure that is the exact same blue sea switch I already own except red.

I honestly came up with that design because the dual switch was cheaper than the single switch, so I bought duals.
Also I killed a contactor and realized that I needed some form of manual override

 

[CanadianEH]

I honestly came up with that design because the dual switch was cheaper than the single switch, so I bought duals.
Also I killed a contactor and realized that I needed some form of manual override

Haha when I first read that I read " I also killed a contractor"

I just bought the resistors on Amazon. Thank's for the tip.

 

[luckielab]

Haha when I first read that I read " I also killed a contractor"

Same here! lol

 

[CanadianEH]

In this setup.. DO I just need the one step down 24->12 converter to go to the 12v distribution panel?

I dont need one for each item which comes OFF the distribution panel do I?

 

[HRTKD]

Just one converter, as long as it is big enough to handle the loads. Converters can be paralleled.

 

[CanadianEH]

Should the converter be located close to the distribution panel with a long wire to my components? or be near the rest of my components with a longer cable to the distribution panel.

my thought is, near the distribution panel with a longer cable back to the components.

 

[John Frum]

Should the converter be located close to the distribution panel with a long wire to my components? or be near the rest of my components with a longer cable to the distribution panel.

my thought is, near the distribution panel with a longer cable back to the components.

If this is an step down dc2dc converter it should be close to the distribution panel.
That way there is less voltage drop over the feeder wire.