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diy solar

1st time Solar Install, unique setup, advice?!

ShepardOneKanoby

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Joined
Oct 25, 2021
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This may have been discussed before, and I'm sure I'll browse these forums soon, however, my time is limited to get this van set asail.

I am following this video from Will Prowse (oh that guy) and some things are a bit different with my own components, yet I believe I've got things close.


So, first time on this site all the while- my van/ solar project is moving at a snail's pace, keeping me docked at a friend's home! I have multiple questions for my specific circumstances and current gear that I've started setting up for my van conversion. Some of which include-

Should I install a kill switch to my solar charge controller between it and my solar panels (because of the alternator hook up that also charges the battery)?

How can I be sure that my DC appliances (from my DC fuse box) can operate 24/7 (cuz of my fridge) and won't require the sinewave to be on at all times?
I will attach a sketch her also of what I have in the works to apply on top of my current setup (alternator connected to sinewave and battery).

One good thing I should mention- is that I have a 2000w pure sinewave inverter and 100ah wet cell that came preinstalled in my van.

Side note- Even while disconnected (no negative connection to the aux battery from the alternator) the sinewave would still function. I have since been using it with that negative connection on the battery. I'm just a bit confused at how it was able to work before, maybe just using main car battery? I have a selenoid on there that should preventing this right? Or does that allow for the batteries to work together but not draining the starter battery? A little confused there.

So mainly those questions at the beginning are my concern, and simply put- How can I hook up DC and AC to my solar setup while keeping the alternator charging capabilities that came preinstalled on my van?
 

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Yes you want a breaker between the solar panels and the charge controller. You want a way to “turn the sun off”.

Having the alternator charge the battery and the solar charge it will not have any problems (unless you exceed the charge rate of that particular battery (look up the manufacturer specs to find it) - but I doubt it will be an issue.

On your inverter can you change the voltage cut-off? Raise it a bit, so if your battery is low - it stops the inverter- leaving you with some capacity for your fridge.

One item I recommend on all batteries- that can get discharged - is a battery monitor. I like Victron equipment, so I would get either the Smartshunt (if you have a Bluetooth phone always around or a BMV712 - if you need the display). There are others as well from other brands. You need to know the amount of power in the battery. Also, because you have a wet lead battery- it needs to be fully charged regularly (or you will kill it early), a battery monitor can help you keep track of the battery charge.
 
Switch is ok between panels and controller. However there is no harm to have multiple charging sources. Solar and alternator can both charge at the same time without issue.

Not sure I understand the DC vs sine wave question. DC is direct battery power. Sinewave is 120 volts alternating current. The DC accessories will operate fine until you discharge the battery. Same with the sine wave inverter... it will operate until the battery is drained. So is this about how long the battery will last? Depends on the loads you have running. Time and experience will tell you how to conserve and how long the battery will provide power.

A 100 ah wet cell is undersized for a 2000 watt inverter. If you plan much time off-grid you will need to expand the battery capacity.

Usually a van is wired with an isolator so that the alternator will charge both the chassis battery and the house battery while the vehicle is running. When the vehicle is stopped the batteries should be isolated so the draw on the house battery overnight should not leave you with a dead chassis start battery in the morning. Need a voltmeter to verify what works.

Here is some reading to help you sleep:
The 12 Volt Side of Life
 
Battery monitor, check! Breaker switch for the solar input, check. Bigger battery,. definitely a check. Voltmeter, makes sense! I'll see what those costs. Yeah right now I have no idea what is drawing what. Can I stick the voltmeter right onto the isolator to check it individually?
 
Oh okay, so SC should be working independently from the sinewave even though this tutorial has the DC running through the sinewave?
 
Oh okay, so SC should be working independently from the sinewave even though this tutorial has the DC running through the sinewave?
Yes the SC is an independent battery charger that can run regardless of anything else.
Yes some inverters(sinewave) have a solar input in combination with the other functions.
 
Screenshot_20211029-085618.pngWill this mt-50 screen that's included be able to replace any type of battery shunt? It's effectively the same thing? Oh shoot, I meant to ask that question before with "DC' not "Sc". But I suppose knowing that the solar charge controller does work in that way is a good confirmation as well. Thank you Time2Roll
 
View attachment 70661Will this mt-50 screen that's included be able to replace any type of battery shunt? It's effectively the same thing? Oh shoot, I meant to ask that question before with "DC' not "Sc". But I suppose knowing that the solar charge controller does work in that way is a good confirmation as well. Thank you Time2Roll
I am not familiar with this controller. It may have a function to display voltage and to log the daily production, peak voltage etc. This is not the same as a battery shunt (battery monitor) that will log all power into and out of the battery to display the state of charge and remaining capacity.

Many people really like a battery monitor. I use nothing but a voltmeter to estimate capacity or monitor what is happening. Can be added later if needed.
 
You guys have been great so far! I did pick up the double kill switch as Nate outlines in his video, and I plan on installing that and not a single hot wire kill switch (as soon as it gets here).

I actually went ahead and hooked everything up today (except the solar) but found no power getting to my charge controller from the battery ?. I believe I have to do more testing with a voltmeter on the system that is already there before I have this setup added. My voltmeter is on the way, and I believe that's all I need to check to make sure everything is getting adequate power? The weirdest thing to me though- is like I've said- the inverter gets power and is totally usable from it's 110 sockets.

I'm thinking (and ready) to upgrade either the battery or inverter if need be, but I'm sure that would be jumping the gun.

Thoughts?
 
And I JUST realized ?how this question would be nearly pointless had I actually put a battery shunt on there beforehand. Wouldn't that be able to tell me the battery's condition before anything else is hooked up to it?
 
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