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What is the appropriate Bulk / Float charge settings for my specific battery?

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morphicpro

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TLDR: I have a 12v 40amp mpp charger with 500w inverter combo.
I'm having trouble configuring my inverter/charger to work correctly with my specific battery.

I have:
The MPPT Solar invert/charger combo 500w 12v - PIP-1012LV-MS
Store page: https://watts247.com/product/pip-1012lv-ms/?wpam_id=3
User manual: https://watts247.com/manuals/mpp/PIP-LV 110_120VAC/PIP-MS LV 1KVA 1-5KVA manual-20200318.pdf

I am using the above invert/charger to charge this battery:
ECO-WORTHY 12V 100AH LiFePO4 3000+ Cycle Lithium Iron Phosphate Fast Charging Battery with BMS

Data sheet on battery:

My first question:
In the manual for the inverter/charger under the settings section there is option 5 for Battery type.
It is recommended to use the User defined option for lipo batteries

Per the note in the user defined section.
> If “User-Defined” is selected, battery charge voltage and low DC cut-offvoltage can be set up in program 26,27 and 29.

Looking at 26:
Bulk charging voltage(C.V voltage)

My first question: Is this the ("battery is at 100%) value or is this the voltage the battery is being charged at in the "bulk" stage of the charging?
Also given the information about my battery what value should this be?

Moving on to the 27th option: Floating charging voltage
Given the charge value above is for the "bulk" phase of the charge, I assume this is indeed the "Float" stage of the charge.

Reviewing Eco worthy's website I seen this.
fr.eco-worthy.com

How to Properly Charge My Lithium Battery? Charging Guide of ECO-WORTH

Charging and discharging batteries is a chemical reaction, but it's claimed that Li-ion is an exception. Li-ion batteries are influenced by numerous features such as over-voltage, undervoltage, overcharge and discharge current, thermal runaway, and cell voltage imbalance. One of the most...
fr.eco-worthy.com fr.eco-worthy.com
> Our ECO WORTHY battery charging parameters consist of the following:
> ✹Bulk/absorb: 14.2V- 14.6V. ✹Float: 14.6v ✹Equalization: 13.6v- 14.0v
>
> But it would be the best for you to choose a specific lithium battery charger. There are many brands on the Internet for you to compare:

Reviewing the battery specs doc
I see this battery is rated at 14.6 for Charge Voltage of 14.6 and a Nominal Voltage at 12.8v

What is the correct Float charge voltage I should use for this battery?

I get what the low cut off is, The idea that it cuts off before the BMS does so I don't have much questions around that.
From what the battery docs say the BMS will trigger the Under-voltage cut off at 9.5v so setting this to 10v should be find.

The other question I have is how does this Charge know when the battery is full given the charge for bulk and float does not indicate 100% charged?
I see nothing in the inverter/charger settings that tell it when it is done charging the battery. IE 100% == 14.6v volts?

I realize I just asked 5 questions any help I can get setting the correct values for my battery would be greatly appreciated.
 
While 14.6 is a full battery,it should never be chosen as a regular charge voltage.
That is 3.65V per cell, and it isn't great for battery longevity.
I like 14.0V absorb, and 13.6V float.
This will still get the cells to 100% charge, and it will never overload a weak cell.
 
Can you speak to why the blog article from the battery manufacturer stated they like the 14.6v bulk and float for lipo?
Also can you speak to any of my other questions? Sorry I know its a lot.
 
I wet with 13.75 charge and 13.35 float.

I bought cells from China which I assembled into a couple of batteries, and there was no guidance in the tech data for charging.

I went with 13.75 volts charging to get capacity close to 95%. I found on this forum recommended charging levels of 3.45 volts per cell. I uses 3.4375

Float was a little trickier And I went with 13.35. I was recommended a bit lower, but when I set this as a parameter, once my battery entered float, chargign amps in were about 1/3rd load amps. My battery was slowly depleting instead of staying fully charged in float. I slowly tweaked the float setting until the float amps in equaled load amps.

This is a 1200 wh battery pack I run up 2.5 kWh a day when using it.
 
100% is not 14.6
14.6 is where the cells reach max charge level.
100% is 13.6 held for a few hours.
Setting to 13.6 keeps the batteries from ever going into overvoltage condition. Unless you have can or other communication with the bms, setting to 14.6 will only cause issues.
If everything is perfect, 14.6 will work fine. But any degradation, and it will start causing issues.
 
In the specs for the battery it states.



If you found the battery can not be fully charged to its full voltage rating (14.6V/29V/58V), the charge tools may not compatible with it, you could check if the charger/controller contains the proper output voltage for LiFePO4 battery.
Click to expand...
Forgive me, but the battery is meant to reach 14.6v at some point correct?

But it also states in a table that 100% is 13.8v??
 
Certainly. At balance point in building the pack, 14.6 would be the charge level reached. It is the point where the batteries fully saturate above the knee.
The battery will then settle down to 13.8V
It is faster to charge to 14.6V but the cells can easily be damaged over time by doing this. And it won’t provide much more energy for use.
Picking a value below 3.65V per cell at or above 3.4V per cell provides far more charge cycles and barely effects the capacity of the bank.
It does reduce the solar stored in the bank though. Because it sends energy MUCH slower into the bank.
 
You battery will charge to over 98% using a charge voltage of 13.8. Using 14.0 to 14.2 charge, 13.5 float is a good compromise.
Set your low volt cut off to 12 volts.
With the inverter charger the default charge voltages of 14.1 bulk and 13.5 float can be used.
 
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