Mpp LV 5048 with small solar array

[Schweg2]

Hello I was wondering if this would work...
I currently have a Mpp 5048 48 volt charge controller in a small solar shed. At the time I only have room to mount the 4 - Renolgy 100watt panels i currently have and was planning on buying 2 Trina 310 watt panels.
Charge controller will handle 145voc and has dual PV inputs. My plan was to wire the 4 - 100 watt panels in series at 22.5 voc ea to one input and the 2 - 310 watt panels in series at 37.5 voc ea to the other input. So I’ll have 410 watts I believe. Would this be enough to charge my battery bank? Battery bank is 550 amp hour lead acid.

My future plan is to expand it once I get more established and it will be strictly be off grid system.

 

[snoobler]

4*100 = 400W on one controller
2*310 = 620W on the other controller

Total 1020W

1020W/48V = 21A. A 550Ah bank needs at least 33A of charge current to hope to keep them healthy, ideally, 55A.

Please link your battery data to ensure there's not a miscommunication.

 

[Schweg2]

I have 12 volt 185 amp hour batteries, 4 wired in series and 3 banks wired parallel. 12 batteries total.

 

[snoobler]

Yep. 555Ah, so you need a lot more solar to properly charge the battery - 55*48 = 2,640W. Could probably get away with about 1600W.

 

[Schweg2]

So I could probably sneak by getting 4 -320 watt panels and using the 4- 100 watt panels then for the time being? How would I wire them so it doesn’t put me over the open voltage?
Thanks!

 

[snoobler]

100W: 4S
320W: 2S2P

 

[gregcron]

100W: 4S
320W: 2S2P

Hey - your post is the first I've seen of a minimum charge current to keep batteries healthy. Do you have any link to more info on that matter?
I'm building a 560ah 24v battery bank (16x 280ah 3.2v Xuba cells), and for solar panels I've got 6x 220w panels for 1880w total. However, one level of them is on sliders so at times, only half of that will be available.
Based off your post, it sounds like even the full 1880w isn't enough to keep a 560ah 24v battery bank happy. I already have all these parts in -- is there risk to continuing my course as planned?

 

[snoobler]

Hey - your post is the first I've seen of a minimum charge current to keep batteries healthy. Do you have any link to more info on that matter?
I'm building a 560ah 24v battery bank (16x 280ah 3.2v Xuba cells), and for solar panels I've got 6x 220w panels for 1880w total. However, one level of them is on sliders so at times, only half of that will be available.
Based off your post, it sounds like even the full 1880w isn't enough to keep a 560ah 24v battery bank happy. I already have all these parts in -- is there risk to continuing my course as planned?

These types of posts are all over the board. FLA/AGM batteries need to be charged optimally at 0.1C, e.g., 100Ah battery should be charged at 10A. LFP batteries don't give a shit as long as you're under their 0.5-1.0C charge rating.

Ranges vary. Most do well in the 8-13% range while some are okay with as little as 5%. Some AGM can go to 20%. A quality battery manufacturer will list recommended and peak charges either by battery model or by their general battery guidelines

10% is always good for everybody.

560Ah should be charged at 56A optimally.

1880W/24 = 78A or 78/560Ah = 14% of C.

Should be fine. Given that you almost never hit peak output, you'll usually be well under the 14% peak.

 

[gregcron]

These types of posts are all over the board. FLA/AGM batteries need to be charged optimally at 0.1C, e.g., 100Ah battery should be charged at 10A. LFP batteries don't give a shit as long as you're under their 0.5-1.0C charge rating.

Ranges vary. Most do well in the 8-13% range while some are okay with as little as 5%. Some AGM can go to 20%. A quality battery manufacturer will list recommended and peak charges either by battery model or by their general battery guidelines

10% is always good for everybody.

560Ah should be charged at 56A optimally.

1880W/24 = 78A or 78/560Ah = 14% of C.

Should be fine. Given that you almost never hit peak output, you'll usually be well under the 14% peak.

Awesome, thank you.

 

[snoobler]

Definitely check your battery manufacturer for appropriate charging criteria and maintenance.