LIFEPO4 Battery discussion thread

[wingnut771]

maybe for a day or 2 just charge to 54v? till its going a bit better

then as imbalance goes down, increase voltage by 0.5V up to 56V. (battery voltage not inverter setting).

I see bat 3 is 54V while other 2 are 54.4V. I wonder if BMS reading is wrong?

 

[DTBA]

Cant be, it should stop below 3.45V. 3.15V is almost an empty battery. It would never balance if it stopped at 3.15V.

Sometimes there are settings that make no sense and have no answer. It is the chinese way.

thats true

 

[DTBA]

then as imbalance goes down, increase voltage by 0.5V up to 56V. (battery voltage not inverter setting).

I see bat 3 is 54V while other 2 are 54.4V. I wonder if BMS reading is wrong?

If cavedog post the voltage before they hit 100% they will be the same. The current is showing 0amps so charge mosfet is off so its the settle voltage showing for that pack

Or if a load on the inverter is turned on and the voltage drops and discharge mosfet kicks in

 

[wingnut771]

If cavedog post the voltage before they hit 100% they will be the same. The current is showing 0amps so charge mosfet is off so its the settle voltage showing for that pack

Or if a load on the inverter is turned on and the voltage drops and discharge mosfet kicks in

Bat 1 is also 0A but 0.4V higher. How accurate is bms reading? Maybe double check with multimeter?

 

[DTBA]

So went and fetched the battery. This is also a pacebms exactly like my original battery. QH Tech. It has 355 cycles about 1 year old and the bms says it has roughly 91Ah capacity left so probably a cell imbalance I need to correct.

Flipped the dip switch and immediately detected in my setup. Nice. Now I have 2 x pacebms batteries and not sure what the new ecoo battery bms is.

Tomorrow its mounting, wiring and fusing day.

View attachment 1909512

old post showing voltage close to the same

 

[wingnut771]

old post showing voltage close to the same

Okay, lets wait for fets to wake up tomorrow.

 

[cavedog]

Meh doesn't look like much balancing. Bat3 just stayed disconnected it seems.



It did intermittently topup during the night.

 

[denmendez65]

Meh doesn't look like much balancing. Bat3 just stayed disconnected it seems.

View attachment 1910061

It did intermittently topup during the night.

View attachment 1910062

Maybe just leave it on the charge controller for a week or more. Set the voltages according to what Wingnut and DTBA mentioned and let it do its thing.

 

[DTBA]

Meh doesn't look like much balancing. Bat3 just stayed disconnected it seems.

View attachment 1910061

It did intermittently topup during the night.

View attachment 1910062

The stupid balancer in pacebms is slow. I am not sure but its a bleed off balancer. It will take weeks if not a month to balance

 

[DTBA]

Set and forgot

 

[wingnut771]

Meh doesn't look like much balancing. Bat3 just stayed disconnected it seems.

View attachment 1910061

It did intermittently topup during the night.

View attachment 1910062

Drain them today and repeat.

 

[wingnut771]

Meh doesn't look like much balancing. Bat3 just stayed disconnected it seems.

View attachment 1910061

It did intermittently topup during the night.

View attachment 1910062

Now that I've had my morning constitution and off my phone I can see a big difference:

Before:


After:


Why is it still saying 10Ah?

 

[DTBA]

Oops I made a mistake with current capacity. 10Ah

 

[wingnut771]

Yes, looks like nothing was done about said mistake.

 

[cavedog]

Yes, looks like nothing was done about said mistake.

Yeah I need to carry the laptop there and unplug the solar assistant cable and then plug it etc I will see if it auto corrects today once I drain it and charge if not I will reset it.

 

[cavedog]

Unrelated to the batteries but as mentioned in the Solar in rain and cloudy weather thread when my inverter is connected to the grid the ac transformer max is 4kW the rest offloads to grid. If I cut power to it then that artificial limit goes away and I can push 5.2kW easy on the ac transformer without overload alarm.

I don't know why it does that and there is no setting for it so looks like for most part I will just run in offgrid mode. I even checked the temps and they are not affected by it. The only thing it doesn't like temp wise is the 3kW geyser element.

 

[cavedog]

I'm also thinking of getting one of those CFE rack batteries. R5000 or R4500 if I can find a seller willing isn't a bad deal depending on the state of it.

 

[cavedog]

So when the solar boom started were these pylontech batteries cheap or something? 2nd hand market is flooded with them now. Crazy. Didn't know they used those pouch cells. Thought they had prismatic cells.

 

[wingnut771]

So when the solar boom started were these pylontech batteries cheap or something? 2nd hand market is flooded with them now. Crazy. Didn't know they used those pouch cells. Thought they had prismatic cells.

View attachment 1910107

They were just the OG batteries. Like a Nissan leaf. but 15S is ****, probably why they don't sell.

 

[wingnut771]

I'm also thinking of getting one of those CFE rack batteries. R5000 or R4500 if I can find a seller willing isn't a bad deal depending on the state of it.

I guess R5k is worth risking it for the biscuit.