diy solar

diy solar

What do I have wrong?

Stewfish

New Member
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Oct 20, 2020
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Its my understanding that 48v is actually 58v. The max I have been able to get on my meter is 53.4v

I have 6000 watts of panels

16s2p of the eve/Lichen 280ah cells can't remember which brand it was.

The system has been running for about a week. We just got back from camping for 3 days and it's only at 53.4v while charging at 3pm and that was a lot of days of charging in our desert . I'm pretty sure I read it should be 58v months ago on a post. Anyway please double check my selections and setting if you could ;)

Found that post:
Absorption 58
Float 54.4
Inverter Cutoff 42.8-48


Is there a 48v lifepo chart from 0% to 100% every 10% and the voltage it should be even thoigh its not linear persay? I have the 12v chart here -

If 14.4 is 100% charge for 12v, then x 4 = 57.6
So shouldn't it discharge down to 20%
12.9v from that chart x 4 = 51.6 for inverter cut off?

Also on a side note the generator start/ or back to grid doesn't work. We are 100% off grid and the genny is not setup yet to the inverter start option so it will default to battery mode settings.

Anyway do I have a setting/# wrong in the paramaters screen?
IMG_20210801_151205560.jpgIMG_20210801_151218755.jpg
 
Last edited:
I have a 12 volt system With FLA batteries.

For charging batteries, even though there is an abobtion voltage, I don’t see that voltage for very long. The first part of the charging is bulk and is pushing as many amps into the system as possible, but it does it less than the absorption voltage. Nearing bulk charge completion is when the absorption voltage is reached, and then the absorption phase starts and the current drops off to zero while absorption remains the same. For lithium, this transition is supposed to happen quicker.

When I’m in float, I will see the float voltage while low amps are pushed. I swap to lithium’s in a couple months, and I expect to see the same for float.

Your absorption voltage seems high to me. I will have Eve 280 cells set up 8S, and I will have 28 volts as my absorption. I am still figuring out my absorption voltage and float voltage, but 14 volts per 12 volts is supposed to get you close to 100%, like 90% to 95%.
 
Midnite Classic-200 Charge Controller settings
All equipment MUST BE Voltage Corrected & Calibrated (VERY IMPORTANT) see link in my signature on how to do it.
Divide Values X2 for 12V. Multiply X2 for 48V.
Absorb:
28.2 for 15 minutes (3.525vpc) (some call this boost)
Equalize: OFF
Float 27.9V (3.4875vpc)
MIn Volts: 22.0 (2.750vpc)
Max Volts: 28.7 (3.5875vpc)
Rebulk Voltage: 27.7 (3.4625vpc)
End Amps: 14A (*1)

(*1): End Amps is calculated from the Highest AH Battery Pack in a Bank. IE: 200AH X 0.05 = 10A 280AH X 0.05 = 14A.
NB: Victron Forum discussion says EndAmps = TailCurrent
This get's the bank charged to full with high amps (Constant Current) and then float (Constant Voltage) tops off so the cells are on average between 3.475-3.500. I am running 7/24/365 so float is used up by the Inverter + provides whatever the packs will take to top off.

** Coulumbic Efficiency for LFP is 99%
This Guide has an extensive Voltage Chart & More info to help you as well. Luyuan Tech Basic Lifepo4 Assembly Guide

BMS: You failed to mention what BMS you are using. Default settings are quite generic and often not quite suitable for ESS with those settings.
ESS = Energy Storage System. The cutoff, delay times and allowable cell differential almost always have to be adjusted.

Hope ti helps, Good Luck.
Steve_S
 
You have 6000W of panel but you set the Total (Utility + Solar) charging current to only 60A.
 
This Guide has an extensive Voltage Chart & More info to help you as well. Luyuan Tech Basic Lifepo4 Assembly Guide

BMS: You failed to mention what BMS you are using. Default settings are quite generic and often not quite suitable for ESS with those settings.
ESS = Energy Storage System. The cutoff, delay times and allowable cell differential almost always have to be adjusted.

Hope ti helps, Good Luck.
Steve_S
Batrium watchmon core with two K9s. One K9 for each 16s battery.

Let me know your thoughts on settings using batrium ;)
 
You have 6000W of panel but you set the Total (Utility + Solar) charging current to only 60A.
I thought that was wierd too. I wasn't sure why 60a was set by default. In the specs it says 60a max AC. I was assuming it was the AC amps mentioned in the specs section, but the 30 amps threw me off. See pdf:

In the solar input section it says PV1 input and PV2 input should be 250v and 18a max each. 8000w max.

I have the LV6548 and a second one to do split phase 240v but it's not setup yet.

Thanks for the help! I'm a noob to setting up my inverter.
 
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