Suggestions for additional panels with controller/battery setup.

[SunPoweredInternet]

Hello all I was trying to weed through the massive amount of info on this forum but felt maybe has quick as this group is a direct question may be faster.

I currently have 3 - 30 watt 1.75 amp sunforce amorphous panels with a 1210RN mppt controller going to 2 vmax sl125 tanks all in a 12 volt system both batteries and panels.

Pretty sure I undersize my amps for that battery and I am at the very edge of the amp range required for the vmax batteries with a 10 amp limit. I am only powering 2 small wireless antennas with PoE 24/7 and it does pretty well keeping up but I would like to add 1 more panel.

The max of the mppt controllers looks to be 130 watts and the lowest that the batteries is suppose to be according to website is 125 and that is only if less then 50% discharge.

So would it be crazy for me to add 1 or 2 more 30 watt panels to the setup, or best to go with a 50 watt panel and add it to the controller?

I may not be asking the right questions I am VERY new to solar power, i unfortunately didn't read on the amp/watt restrictions on batteries and controllers until after I got them. Newbie mistake.

From what I see my load is between 1 to 2 amps so day to day I do well a few cloudy days and it may take a couple days to get caught up, I was hoping with a couple more amps I could shorten up that time and try and keep my batteries well conditioned.

Any suggestions would be great! Thanks all.

[Mike90250]

I'm understanding you have 2, 125ah batteries paralleled together, creating a 250ah battery ?
Powering a constant 2ah PoE load ?

Daily load is then 48ah @ 12.5V = 600wh

PV is 90W for 4 hours = 360wh
or PV is 90W for 5 hours = 450wh daily harvest.
So your batteries will eventually fail from undercharge

What your PV should be is about 3 hours (winter) would be about 200 - 250 watts. This will get you through a couple cloudy days
A single 250W pv panel and a 20a MPPT controller would do it.

How it is working is a mystery, so your loads must be less then you reported.

[SunPoweredInternet]

This is awesome info! Thanks for the quick response, I will answer what I can below for now.

I'm understanding you have 2, 125ah batteries paralleled together, creating a 250ah battery ?

correct 2 SLR125s

Powering a constant 2ah PoE load ?

I think it is closer to 1, it is a really crappy 100w inverter, with 2 PoE injectors running at .5 amps each for 110v. When it warms up the fan kicks in and the highest I saw was about inverter run as high as 2 amps. I had it plugged in to the meter on the controller and saw about 30 amps in 24 hour period. I will reset my meter tonight and try to get more accurate numbers.

Daily load is then 48ah @ 12.5V = 600wh

so with this math looking at 30ah@12.5V = 375 wh

PV is 90W for 4 hours = 360wh

in series with another 40W panel could I in theory hit 520wh, and then redesign this entire thing for next year with bigger pannels and controller. I fully realize how close and probably overdrawn I would be if we have a cloudy streak but I was just wondering. Easier to stomach $90 for a 40W panel right now and get new controller and 2 new 150 watt panels next years since I just bought this pathetic under power MPPT controller. *me shaking my head*. Thank goodness my wife doesn't read these forums. I did however get her Internet over a 1/4 mile without having to run a wire... yet..

or PV is 90W for 5 hours = 450wh daily harvest
So your batteries will eventually fail from undercharge

YUP... all summer I was able to sustain a load for 3 months with a PWM craptastic controller using a 400W modified sine wave inverter. When the sun moved down and we had about 10 days of rain my batteries did fall to about 50% so I conditioned them for a night and put them back out, and days got shorter I only get about 5 hours of solid sun a day now so need to move the panels it appears and add more for better charge because winter will suck with this setup.

The note on the charge tanks documentation recommended is 8A-35A. (why didn't I read that before I bought the 10 Amp controller) and the max PV input on the charge controller is "Max. PV Input Power 12V System 130W" (banging my head on the table now)

[jflorey2]

I currently have 3 - 30 watt 1.75 amp sunforce amorphous panels with a 1210RN mppt controller going to 2 vmax sl125 tanks all in a 12 volt system both batteries and panels.

Pretty sure I undersize my amps for that battery and I am at the very edge of the amp range required for the vmax batteries with a 10 amp limit. I am only powering 2 small wireless antennas with PoE 24/7 and it does pretty well keeping up but I would like to add 1 more panel.

So that's 250ah of battery. You'd need ~25A of charge current. Your CC won't go above 10 amps.

So you need a new CC and some larger panels, around 300 watts.

[SunPoweredInternet]

Thanks for the quick reply. At least I won't have to buy a new meter if I get a bigger MPPT TRACER 3215RN CC.

[Sunking]

You need real panels for a total of 300 watts and a 25 amp controller.

Surprise Surprise Surprise. I bet you are real happy with yourself right about now knowing what you have is worthless.

[SunPoweredInternet]

Yes you are very helpful thanks for you comments of encouragement.