Solar feedback thread #1000

[tmart]

I've read a bunch of solar posts on here and they've helped me out a lot on figuring out my setup. Now that I'm about to pull the trigger and get to work I was wondering if anyone would like to give some feedback on my plan and some questions:

Are circuit breakers ok instead of fuses? I'd prefer it so I could reset easier.

I'm planning on using relays tied to the charge controller LVD to keep me from running the batteries too low, like in this post. Should I fuse this circuit? And what gauge should I use? I couldn't find the resistance of my relay (linked below) anywhere.

The batt is going under the bench on the passenger side, while the charge controller,, inverter, fuse block, etc will be on the driver side.

For the panel to cc run, I can't decide what to do about wiring. The panel comes with 12 awg leads, but it's a long run from roof through vent into engine bay and through a hole I'm drilling into the bench cavity. Would 10 awg be better? And could I just attach the #10 to the #12 at the stock lead connectors?

I'm also planning on switching the ACR ground to allow me to select force separate or automatic, as shown in this thread. I don't care to force combine. What gauge should I be using there (how much current runs through that line?)

My "BOM":
Fuse between panel and cc
Fuse between cc and battery
Fuse between batt and inverter relay
Fuse between batt and fuse block relay
Fuse between batt and ACR
Solar Panel
Charge Controller
Inverter
Relays
Relay Cover
ACR
Battery
Fuse Block

I know I've linked circuit breakers instead of fuses, just hoping those are ok. If I hear otherwise I have some fuses open in other tabs. If all goes well, hopefully this'll be useful to others.
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1990 Vanagon 2.2L Manual
The van that samba built

[Sodo]

Fuses should be at the battery. The battery has the fire in it, you want to break the connection nearest to the battery.

Yes you can connect 10ga to 12ga. The wire size is not for max current its for minimum resistance. Or use 2 12v panels at 24v then small wires are OK.

I’m no expert. I just slammed a 100w system together before a trip and it worked great. 18 days on the road and I have a crappy aux battery but my Truckfridge worked fantastic the whole time. You can see which days the van was driving all day (alternator charging the battery, for example Apr9)

I used a Victron charge controller, very happy for the Bluetooth & reports on my phone. $104

Heres the last 30days. Theres more detailed info too. I left on Mar30, rtnd Apr16. Fridge is still running, haven’t emptied it yet (lazy). Where Vans parked currently its not getting great sun plus its Seattle.

I would be grateful if a solar expert could suggest the proper amp-hrs battery capacity I need from this.
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[jimf909]

Wow! That’s fancy. Is that a Victron with Bluetooth dongle? Where did you buy it?

Thanks.
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- Jim

[Sodo]

No dongle; Bluetooth inside.
$109 on Amazon
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[dobryan]

[tmart]

Hey Sodo,

I think I like that charge controller better than the one I had posted. One question, what'd you do about ground fault protection, this is from the manual:

[RichBenn]

[jimf909]

[tmart]

Hey Rich,

Thanks for the help with the grounds. I think that's what'd been giving me trouble. In the van, ground and negative is synonymous whereas in homes they aren't necessarily...right?

Are you saying fuses are a must? Or can I use the circuit breakers I linked above? I already have the circuit breakers here and would love to stick with those if I can. With regards to location, they're going to be attached to the batt box or right next to it (undecided), so very close to the battery.

On another note, would standard electromechanical relays be safe to use? The relays would be on the psgr side of the bench and the batt on the driver side. I know people like to use SSR because the EM one's can create sparks when the contacts open/close, bad newss with batt offgassing. How close is too close? The SSR's I linked didn't seem up to snuff. I tested and the labels were off (load and input sides switched) and I couldn't find continuity on the load side. Also didn't seem like the input side was current limited. Anyways, looking at these now.
_________________
1990 Vanagon 2.2L Manual
The van that samba built

[erste]

[shagginwagon83]

Yeah Victron now puts the bluetooth in the controller. This will allow you to gather information about solar charging and battery voltage.

However if you really want to gather data, you should look into a Victron 712 with a shunt. The shunt goes in line with your batteries ground. It can tell you how many amps you are pulling and more information. I have a friend adding this to a Lithium setup and can't wait to play with his app.
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Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[dobryan]

[Wendy.the.Westy]

A few thoughts from an EE.

Using the solid state relays connected to the LVD load terminals of the charge controller is an attempt at being clever, but it's actually self-defeating. This setup will have a small continuous current through the relay control coils that will always be slowly discharging your aux battery. Of course, the charge controller circuitry will interrupt the relay coil current once you reach the low battery voltage threshold at 11.1V, but now your aux battery is fully discharged.

A better solution would be to use a charge controller with low voltage load disconnect circuitry that is rated for the load that you will be running. Then you can connect your fuse panel directly to the load terminals of the charge controller as intended and ditch the interposing relay concept.

The Morningstar PS-MPPT-40 charge controller offers 30A of load control current with an adjustable low voltage disconnect setpoint so if you accidentally leave a house load on, the charge controller will disconnect before your aux battery is fully drained.

Hope this helps ya!
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ID.BUZZ

[tmart]

Thanks for the input about the relays Wendy. I'd considered the constant draw and it's just going to be something I'll have to live with...kinda.Since drawing my schematic above, I'm actually giving each relay it's own circuit and adding a sdpt on-off-on switch in front of each. This'll let me select lvd, forced off, and forced on. Still have the relay draw when on, but when forced off, batts get to charge w/o any draw. The draw is pretty low, <1 amp with the coil relays. A higher amp lvd would be nice but too much $$$ at the moment. Tangential question, but would charge controller lvd negative act as ground when I switched to forced on? And would that be ok? If not, I could use two dpdt swtiches instead, that'd let me switch both the power and ground from lvd+ and lvd-, to batt+ and batt-.

As an EE could you fill in on any of my concerns about fuses vs. circuit breakers or using coil relays in proximity (if you could call ~3 ft away that) to lead batt?
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1990 Vanagon 2.2L Manual
The van that samba built

[tmart]

After chewing on it for ~30 s, I think I'll be gonig the dpdt route above.
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1990 Vanagon 2.2L Manual
The van that samba built

[Sodo]

[Abscate]

[Wendy.the.Westy]

[tmart]

Took a while to get back on here, but I got things all wired up in the van. Or almost at least. I absentmindedly built everything so that the one circuit breaker coming from the ACR is good and close to the batt, but the others are all next to the components they protect. It's not too far across the heater core, but I'm not a fan so I bought some flexible conduit that I'll pull the wiring through today.

Here's the schematic of the system as installed. Lot of detail so I uploaded it in full resolution:

_________________
1990 Vanagon 2.2L Manual
The van that samba built

[Wendy.the.Westy]

Nice schematic update! Are you happy with the functionality so far?
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ID.BUZZ