My first LifePo4 48v battery build. Am I ordering the correct BMS? Daly 16s 48v 250a with Growatt SPF 5000 SE

Hi All,
About to order the components for my first battery build and want to make sure I am ordering the correct BMS.

Inverter/Charger
Growatt SPF5000SE (Spec pic below) Its maximum solar charge current is 100a and is connected to 5400w PV Array. So should get 100a @ 48v in full sun.

Batteries
16 x 3.2v LifePO4 202Ah CATL

The BMS I am looking to buy is a Daly 250a (Pics below). Originaly I was going to buy a 100a but realised that the amp rating on these BMS,s is for the output and the charge current is half the output rating.

Is the 250a the one to buy?

Thanks

5000W/48V/.85 (inefficiency) = 130A discharge; 250A BMS is sufficient.

The charge current of 100A is < the 125A charge limit of the BMS is sufficient.

Bought the same BMS for both of my battery banks (280ah 16s) for my setup with the Growatt 5k.

We're you able to connect the daly bms to the Growatt 5000 es version. Did the growatt allow the bms to stop before over charging battery?

Struc said:

Bought the same BMS for both of my battery banks (280ah 16s) for my setup with the Growatt 5k.

Click to expand...

Did the Growatt 5k in li position or US5 .Manual say user can not set charge amount in li bms position. Did the bms Over ride growatt 5k . My battery should not exceed 58.4. It charges to 61

The Growatt SPF 5000ES will not communicate with the Daly BMS.

I have my Growatt Battery Type (05) set as "US2" Then use the settings in 19,20 and 21 to regulate the battery.

The most important settings are 19 and 20.
I ended up buying 16 x Eve 230Ah batteries with 250Amp BMS. (Screen shots below how I set my BMS)

Daly BMS
Settings on the BMS are under the limits of the Batteries ie. max voltage of each cell is 3.65V so BMS is set under this at 3.60v (Voltage Settings for BMS Chargers and Loads PDF attached below) Last page of this document is what I used to define BMS settings. These BMS settings are there to Protect the batteries from overcharge and undercharge. The only reason the BMS will shut down is if the settings on your Growatt are trying to exceed these values.

Growatt SPF5000SE
Again I used the "Voltage Settings for BMS Chargers and Loads.pdf" to define these settings with some adjustments from myself to extend the life of my batteries. I want to get the maximum storage capacity from my batteries but also extend there life as much as possible. So I only charge to 80-90% of there capacity, (defined in setting 19 "CV charge voltage") had to play around with this a bit and ended up set at 55.4v. This means the inverter will stop charging when it sees the battery at this voltage. Note, while under charge the batteries go up to 55.4v but after about 30-60 mins when not undercharge they settle at about 53.5v (53.5/16 = 3.34v per cell) 3.34v per cell is about 80% state of charge (resting voltage, doc attached "cell no load voltage").
As for setting 20 "Float Charging voltage" I have this set at 54.4v. Not sure how the inverter references this setting as I assumed that if the battery voltage drops below this it will start charging again, but mine doesn't. My inverter only starts charging the battery again if the voltage drops below about 53.0v. ???

Setting 21 has never been a problem as I haven't depleted my batteries lower than 30%. Mine is set to 48v.

Hope this helps...

Thank you
I have experince very similar results. I had 19 and 20 at 58.4 for both. Never reached .I did get to 56.2. Wrong I had one of my batteries swell. I replaced. Reduced 19 to 54 and 20 to 54.
I removed my daly bms early after 1 hour of use. The Growatt 5000 took over was charging for 61. Stopped that very quickly.
I find on the US2 setting alone seems best. Battery likes the 53.4 area. Which is 75% for me. I have not a found away to change this setting.
I have mine cutoff seat at 46 .
I am watching closely.
I was wondering if I can use bms without inverter. Saw video they hooked it to regular battery charger. I have 12 volt battery charger. I would do this if possible to see my batteries voltage etc. Use this to balance etc. Not sure how to do this with 12 volt charger.
Thank you very much for confirming and explaining use of bms. It helped me alot.

No Problem.

Do I understand you correctly.. You have removed your BMS? and operating without it?

I think you should set your "20" float voltage at least 1v lower than your "19" charge voltage. Otherwise you risk micro cycling your batteries which is not good for them..

If you want to charge you batteries from to watch the voltages from mains power (battery charger) instead of waiting for solar you could use the inverters utility function for this.

Ok, so set 20 1 volt lower. Will do.
What do you have 13 set at.
I am not sure I understand inverters utility function. I do have grid power avaliable. Would use 12 volt charger to solely see bms settings etc
Thank You for your help

I have 13 set to 54v and 12 set to 50v. Both these settings at irrelevant for me. My system is sufficient for my power usage so while I am wired to Utility power the breaker is switched of. I have only used utility once to recharge my battery when I accidentally left my freezer open over night and it flattened my battery at 3am in the morning.

BMS should always be used in the running system, not only does it prevent over and under charge it also balances the cells.

To use Utility to charge your battery;
Connect your inverter to utility power with adequate wire size. Enough for 5000W

Best to do first thing in the morning when your battery needs charging.
Set "11" to whatever amps you want to charge at, I charged mine at 30Amps. Also check "02" is set higher or equal to "11"
Set "14" to either "CSO" or "SNU" so it will use utility
Turn off your battery
Turn off your solar Panel input
This should force the inverter to use utility power, you may need to restart it. ("01" needs to be set to anything other than SUb)
Turn on battery. Should start charging, I found I could alter the Amps in "11" while it was charging if you want to start lower than 30 amp

If it does not start charging you may need to edit "12" to be at a higher Voltage than you battery is currently. ie: if your battery is at 53 volts but "12" is set to 50v.


What voltage and amps is your solar array?

Mine is currently set wrong. I have 10 panels 540w each (5400w total) each panel is 49.5 v (Open circuit) and 12.97 Amps. I have 2 strings so 5 panels in series (5S2P) this means my open circuit voltage is about 247vDC and amps 25.94. At the inverter its about 190-200vDC. This inverter is only capable of 18amp charging from solar. So the maximum charging watts i will ever see is 200x18= 3600W. Should change my panel configuration. But expanding my system anyway.

New firmware for the inverter will improve this for me increases to 24amp charging see: https://diysolarforum.com/threads/growatt-spf-5000es-firmware-update.35171/#post-479915

Well I have learned enough to keep my mouth shut and fingers off the keyboard.

Sorry ,it appears I should have proof read before posting. People,dogs etc chaos. I just pushed post. Lol

magnathea said:

Hi All,
About to order the components for my first battery build and want to make sure I am ordering the correct BMS.

Inverter/Charger
Growatt SPF5000SE (Spec pic below) Its maximum solar charge current is 100a and is connected to 5400w PV Array. So should get 100a @ 48v in full sun.

Batteries
16 x 3.2v LifePO4 202Ah CATL

The BMS I am looking to buy is a Daly 250a (Pics below). Originaly I was going to buy a 100a but realised that the amp rating on these BMS,s is for the output and the charge current is half the output rating.

Is the 250a the one to buy?

Thanks

Click to expand...

I would not recommend a Daly, I own 3 of them.