Using two different types of Li batteries, one system - Is this possible?

[Capt Bruce]

Background:
I have 48 Li-ion batteries, that I'd like to connect to my current system, and these 48 batteries are 3.6v, with 109.6Ah, 396Wh, and are currently in a 16s configuration, (not sure if i should be in a 13 or 14s actually)( they have not been connected yet)
The batteries are Panasonic model BZ-MA101BTA which I can find no info on.
I was thinking of making three 1p16s batteries. the terminal are on each end, so a 3p16s config would be difficult.
the would add 150% to my storage with these, as a start.

I currently have a single LIFEPO4, battery connected to my system, it is a Meritsun LFP200-48 10KWH 200Ah. Which I'm finding out, is not nearly enough!

My inverters, are 2 MPP LV6548 in parallel, providing split phase 240.

I know enough to get in trouble and very confused!!

Questions:
My over all question is, If BMS's control the charging and discharging protection of LI batteries,:

• why does the inverter charger setting matter?
• why wouldn't each of the BMS's/Batteries just take what they need to charge?
• what would the negative points of using and discharging each type of battery be? (assuming the charging issues can be overcome!)

Plea:
help! lol


this is my first post...
I can provide pictures if needed.

 

[sunshine_eggo]

Background:
I have 48 Li-ion batteries, that I'd like to connect to my current system, and these 48 batteries are 3.6v, with 109.6Ah, 396Wh, and are currently in a 16s configuration, (not sure if i should be in a 13 or 14s actually)( they have not been connected yet)
The batteries are Panasonic model BZ-MA101BTA which I can find no info on.
I was thinking of making three 1p16s batteries. the terminal are on each end, so a 3p16s config would be difficult.
the would add 150% to my storage with these, as a start.

I currently have a single LIFEPO4, battery connected to my system, it is a Meritsun LFP200-48 10KWH 200Ah. Which I'm finding out, is not nearly enough!

My inverters, are 2 MPP LV6548 in parallel, providing split phase 240.

I know enough to get in trouble and very confused!!

Questions:
My over all question is, If BMS's control the charging and discharging protection of LI batteries,:

• why does the inverter charger setting matter?
• why wouldn't each of the BMS's/Batteries just take what they need to charge?
• what would the negative points of using and discharging each type of battery be? (assuming the charging issues can be overcome!)

Plea:
help! lol


this is my first post...
I can provide pictures if needed.

Not at all a good idea.

Li-ion have a strong voltage to SoC relationship and experience very little voltage drop after charging. LFP are a little more like lead-acid, they need to be charged to a higher voltage, and then they'll settle to a lower voltage. Makes matching the different chemistries challenging. they will also behave very differently in charging and discharging.

Your expectations of BMSs are not always correct.

1) BMSs only control charging and discharging if they are in communication with the hardware (inverters & chargers).
2) If supplied with more than they can handle, BMS not in communication with the hardware has no ability to regulate charge besides completely stopping it. Choice is 1) whatever the charger is supplying or 2) Zero.
3) Given the two different chemistries and the certainty that the Li-on won't be in communication with your hardware (you can't have two different BMS brands/protocols communicating with your hardware as they would conflict), the BMS is a "dumb" traffic cop. If voltage or current to too high or too low, they are cut off.

Discard the notion of mixing Li chemistries and buy more BMS compatible LFP.

 

[Capt Bruce]

Not at all a good idea.

Li-ion have a strong voltage to SoC relationship and experience very little voltage drop after charging. LFP are a little more like lead-acid, they need to be charged to a higher voltage, and then they'll settle to a lower voltage. Makes matching the different chemistries challenging. they will also behave very differently in charging and discharging.

Your expectations of BMSs are not always correct.

1) BMSs only control charging and discharging if they are in communication with the hardware.
2) If supplied with more than they can handle, BMS not in communication with the hardware has no ability to regulate charge besides completely stopping it. Choice is 1) whatever the charger is supplying or 2) Zero.
3) Given the two different chemistries and the certainty that the Li-on won't be in communication with your hardware (you can't have two different BMS brands/protocols communicating with your hardware as they would conflict), the BMS is a "dumb" traffic cop. If voltage or current to too high or too low, they are cut off.

Discard the notion of mixing Li chemistries and buy more BMS compatible LFP.

1st - thank you!

Connected battery was never setup to be communicating to the 6548's... and I still haven't found someone, or the way to do it.
The installer never finished the job, and no other local person will help me, because "I didn't but it from them", sigh I'm in a remote area, in Puerto Rico...
Do I need to just use a normal cat5 wire, with standard configurations, and just plug it in? can I hurt anything if wrong?

 

[sunshine_eggo]

1st - thank you!

Connected battery was never setup to be communicating to the 6548's... and I still haven't found someone, or the way to do it.
The installer never finished the job, and no other local person will help me, because "I didn't but it from them", sigh I'm in a remote area, in Puerto Rico...
Do I need to just use a normal cat5 wire, with standard configurations, and just plug it in? can I hurt anything if wrong?

I can't say. I don't know if the batteries are compatible with the inverter.

You've now confirmed that your BMS have no way to "regulate" charge or discharge by any other means than completely cutting it off if limits are exceeded.

 

[Quattrohead]

I would not mix them, the LI batteries are too fickle to mess around with.
LifePo4 and lead are way more stable and will take some "configuration issues" without exploding.

 

[DThames]

If you know what you are doing, mixing them could work for you. I would keep the Li-ion cells inside the normal discharge curve of the LiFePo4s. I did it (for testing) with a 24v setup, 8 LiFePo4s in series paralleled with 7 Li-Ion in series. I did a test and posted a report on this forum site. When the LiFePo4 were fully charged to about 3.55v per cell, the Li-ion were at 4.05v per cell. When the LiFePo4 were discharged to 2.90v the Li-ion were at 3.30v per cell. Operating Li-ion between 3.30v and 4.05v gives you less than full capacity from the batteries. That range also keeps them in a very gentle charge cycle. I observed some micro-cycling between the two batteries. The major part of the current(amps) comes from one pack first, then the other, then switches back. This causes some back and forth current as they constantly try to stay at the same voltage while delivering differently, depending on where their SOC is.

I would rather not have Li-ion in my house system unless they were away from the house. I use some in a portable power box but it is not charged unattended (for days).