My 1st DIY LiFePo4 system for Hot and Wet Environment.

[adriansantos]

Shifted to LiFePo4, I dont like the Lead acid batteries

The system is for temperate region, wet and dry season only.
The 24v system consist of:

8 x 3.2v Sinopoly Battery 90ah LifePo4 (2nd hand)
Bms generic of Daly, 60/30
Victron smartsolar 100/20
24v to 12v 10a converter
1 x 340watts JA solar Poly panel (No pic since installed it in the roof)


Later pics shows 2x 24v fan connected to Temp control module. Our temp here down south of the Philippines reaches 36 deg Celcius, but inside this DIY container, temo reaches max of 41 deg on a very sunny day and no ventilation.

Also connected a satellite juction box, with 24v to 12v converter

** The wires are just AWG 10. The system is only to supply my aquaponic system and some night lights which reached a max of only 75 watts.

**Did bottom then top balance, and then capaciy test. Got 2400 watt hrs at 2.8v per cell. Pretty good for a second hand batteries which cost almost 320 usd. Was better with active balancer but i fried it when i made a mistake with sequence of wire when i was making the final installation.

Big thanks to mr prowse on his videos, helped me a lot in building this

 

[snoobler]

I'm sorry, but this is horrifying:

3.41-3.74V cell range?

Not sure how you top balanced, but these show no evidence of ever having been top balanced, or you have some seriously messed up cells, or your BMS isn't working, or your BMS isn't configured properly.

You should check all 8 cell voltages when they are at their lowest state of charge to assess what's going on.

 

[adriansantos]

View attachment 26330

I'm sorry, but this is horrifying:

3.41-3.74V cell range?

Not sure how you top balanced, but these show no evidence of ever having been top balanced, or you have some seriously messed up cells, or your BMS isn't working, or your BMS isn't configured properly.

You should check all 8 cell voltages when they are at their lowest state of charge to assess what's going on.

Yeah this happened now since my active balancer got fried. waiting for replacement. but with the balancer all cells are at 3.55

The mppt is at float mode with that pic.


This pic is with the 5a Active balancer.
Absorption charge set at 14.1v and float at 13.5 x2

 

[snoobler]

Active balancers can be counter-productive unless they have a cut-off below which they won't work. If you have imbalanced cells, you want them balanced at only the top. Active balancers adjust balance throughout the range maximizing capacity of the total battery.

I'd adjust your charge voltage down until #7 is maxed out at 3.6 or so. IIRC, the BG-8S isn't a BMS but has some very limited balancing functions. The Daly should be able to get you there eventually.

 

[adriansantos]

Active balancers can be counter-productive unless they have a cut-off below which they won't work. If you have imbalanced cells, you want them balanced at only the top. Active balancers adjust balance throughout the range maximizing capacity of the total battery.

I'd adjust your charge voltage down until #7 is maxed out at 3.6 or so. IIRC, the BG-8S isn't a BMS but has some very limited balancing functions. The Daly should be able to get you there eventually.

Sorry for the confusion, the pic i showed on my reply was the voltage with the active 5a balancer and not with the Bg-8s which really is just a passive one and really just good as a monitor.
Here is my active balancer that got fried.
Thanks for the advice, have adjusted my abs voltage to just 27.4v now. Didnt notice that one

This is also the generic BMS which has a cutoff of 3.75v

 

[digit]

i think that breaker w the blue handles is for AC only, not DC, pic was too blurry to tell but i just returned one that looked identical.

 

[gnubie]

i think that breaker w the blue handles is for AC only, not DC, pic was too blurry to tell but i just returned one that looked identical.

A close up of the front of the breaker would settle it.

 

[adriansantos]

i think that breaker w the blue handles is for AC only, not DC, pic was too blurry to tell but i just returned one that looked identical.

50a DC

 

[digit]

I stand corrected