Please Critique My System

[ArmorAbby]

Hey Folks!! 
Wow, last time I commented here I was still in a car. I HATED it. 

Now, I've had the van for a few months. Have rebuilt two... or three times : Pretty  happy with my build now. 
And have ventured into Electricity. 

Came back to this forum because I'm really annoyed by the haters and lack of moderation at the Reddit Sub, although I still love my subbies there. 

So I wanted to ask the fam here to help me make an addition to my solar. 

I used a Renogy Kit. 
200 Watt Mono Panels.  These go into a Wanderer Charge Controller, which then goes into one of those EverStart 80ah batteries from Walmart.  
This battery is also connected via an 80amp relay type isolater with 2 or 4 gauge wires and 90amp fuses here and there.   
The isolater is powered by a wire that used to power the tv that came with the van. 
All are grounded with the bolts in the floor/step area of the barn door entrance

It's been working great. 

So, here is where my questions come in.   
I'm now going to add back in (it was in before but I over discharged it so bought the EverStart and took this to get charged elsewhere).... 
I'm now going to add back in my WindyNation 100ah battery.  
So I will now have two batteries of 180ah.

First question is - These two batteries can go together right? They're both sealed... from what I can tell, and both deep cycle. 

My next question is the order of adding in the wires.   

Please tell me if I'm wrong. 

If I understand correctly, I will do this at night, so no power is coming into the panels.  I will put the Positive from charge controller on the first battery, and the negative from the charge controller on the second battery. 

Then I will go from house battery to house battery - positive to positive - negative to negative. 

Does this all sound correct thus far?  

Then, if all that is in order.... 
I would like to use a "low-voltage disconnect" device and something to tell me my volts while my system is running. 
Would someone recommend a couple good brands for me look into with this or these devices? 

Also, since the solar system goes from one positive battery side, and the other battery negative side ---- Do I do my inverter this way also? Or the 'low-voltage device' - or fuse box or anything I will hook up to the terminals from this day forward? 

I have something call a 'shunt' that I ordered because it was recommended in a cart somewhere... but I honestly forget what it is for and why I got it.   

 And once this is all done -- I will finally put pictures of my build up....   or that's the plan anyway...

 

[jonsun]

probably not a great idea to mix the batteries. And no you're wiring them wrong. it will give you 24v like that. you hook + to + and - to -

you dont need to do it at night. you just hook the batteries up first, then plug the panels in.

 

[ArmorAbby]

probably not a great idea to mix the batteries. And no you're wiring them wrong. it will give you 24v like that. you hook + to + and - to -

you dont need to do it at night. you just hook the batteries up first, then plug the panels in.

That's what I said.... + to + and - to - 
*edit* hooking charge controller to the battery connection is + on one, - on the other, that's what the Renogy manual says for 12v and adding AHs.. not the battery to battery connection...

and it has to be at night because the panels can't be plugged into the charge controller when it's unhooked the battery...  unless there is no sunlight powering them... I don't want to have to  unhook the panels before unhooking the charge controller....

 

[jonsun]

should've read the line under it

but no just hook the CC to one of the batteries as if you only had one, then run the jumpers. or your way, whatever.

 

[ArmorAbby]

According to Renogy User Manual... 


""When two or more batteries are connected in parallel, their voltage remains the same but the AmpHour ratings add up.""

Then there is a picture of the Charge controller, going from + on one battery, and - on the second battery
Then each battery going + to + and - to -

 

[jonsun]

I dont think there's a difference as long as it's jumped right.

 

[ArmorAbby]

should've read the line under it

but no just hook the CC to one of the batteries as if you only had one, then run the jumpers. or your way, whatever.

'Whatever' isn't going to cut it.... 
Thanks though...

 

[tx2sturgis]

If I understand correctly, I will do this at night, so no power is coming into the panels.  I will put the Positive from charge controller on the first battery, and the negative from the charge controller on the second battery. 

Then I will go from house battery to house battery - positive to positive - negative to negative. 

Does this all sound correct thus far? 

You are attempting to 'load balance' the batteries but with mismatched batteries they will never be totally in balance.

It will work, for lighter loads and less discharge, but, the battery with lower capacity will drain more quickly if you intend to pull the batteries down to a low state of charge.

You can hook them up in parallel, then use opposite battery's terminals, as you describe, but you will have issues if you intend to discharge them occasionally overnight for heavy loads.

The solution is to use two batteries of equal capacity and more or less equal age and use.

 

[jonsun]

It cuts it.

but how would you hook up 3 batteries?

 

[tx2sturgis]

I have something call a 'shunt' that I ordered because it was recommended in a cart somewhere... but I honestly forget what it is for and why I got it.  

In this setup the shunt is for a remote amp meter, or remote monitor.

Did you buy one at the same time?

The remote amp meter and the shunt are supposed to be a matched set, more or less, one intended for use with the other.

 

[Putts]

It's a minor point, but your way is best practice. Mixing the two batteries, however, is not a good idea. They may be the same type, but they're going to have enough differences that it will be sub-optimal. I'll let someone with more experience say why, but I wouldn't do it.

Yes, you should hook the inverter to the same point on the batteries as the CC, but both lines should be fused/breakered separately.

 

[jonsun]

you're definitely NOT supposed to fuse CC to battery line. If it blows your fry the CC.

 

[ArmorAbby]

It cuts it.

You're missing wires here.....

 

[jonsun]

it's a generic image from google. If you think it's missing wires you def have something confused.

 

[Putts]

you're definitely NOT supposed to fuse CC to battery line. If it blows your fry the CC.

Woah! My mistake then. I'm going to have to re-look at my system design. Is what I'm seeing there just always a switch and not a breaker?

 

[jonsun]

IDK I was always told like you to fuse it, then I read a few CC's manual and it said not to.

 

[ArmorAbby]

It's a minor point, but your way is best practice.  Mixing the two batteries, however, is not a good idea.  They may be the same type, but they're going to have enough differences that it will be sub-optimal.  I'll let someone with more experience say why, but I wouldn't do it.

Yes, you should hook the inverter to the same point on the batteries as the CC, but both lines should be fused/breakered separately.

Hmmm.. yeah, I hadn't thought about equalizing or balancing during the connection --  I only did the total math at 185 ah. But that does make a lot of sense.....  

Thanks for that. 

Now I'm not sure if I'm going to keep my twice-as-expensive-100ah battery and get another which I don't have money for now..... or give it away and get a second half-the-price 85ah battery and have two of those....

 

[Trebor English]

you're definitely NOT supposed to fuse CC to battery line. If it blows your fry the CC.

At the battery there should be a fuse so that if the wire shorts the battery won't overheat the wire.  At the charge controller there should not be a  fuse.  The wire must be fat enough so that the charge controller can't overheat the wire. 

Between the panels and the charge controller the wire  must be big enough so that the panels can't overheat it.  A fuse is not necessary there. 

The fuse at the battery must be big enough so that the charge controller can't blow it.  However, if the wire shorts, the battery will blow the fuse rather than overheat the wire.

 

[ArmorAbby]

You are attempting to 'load balance' the batteries but with mismatched batteries they will never be totally in balance.

It will work, for lighter loads and less discharge, but, the battery with lower capacity will drain more quickly if you intend to pull the batteries down to a low state of charge.

You can hook them up in parallel, then use opposite battery's terminals, as you describe, but you will have issues if you intend to discharge them occasionally overnight for heavy loads.

The solution is to use two batteries of equal capacity and more or less equal age and use.

Thanks, this makes so much sense and I hadn't even considered it. I was just adding up AHs

So now, I have a more expensive WindyNation 100ah battery that I can't afford another right now... .
and I also have a cheap EverStart 85ah battery.. that I could afford another...
   
I'm gonna go with a second EverStart
I guess I'll give away or sell the WindyNation.....

 

[ArmorAbby]

In this setup the shunt is for a remote amp meter, or remote monitor.

Did you buy one at the same time?

The remote amp meter and the shunt are supposed to be a matched set, more or less, one intended for use with the other.

It's two little pieces... one little monitor looking thingy... and one small but rather heavy piece with two terminals/bolts  

Fits in the palm of my hand