Magnum Energy MS4448PAE LiFePO4 Charger Settings:

[Denis]

Update, I have readjusted my absorb voltage to 58.4v, while doing test and trying to rebalanced my cell with the new one, I noticed that there's only 2-3 amps more to reach the full charge zone of 3.65v, stop at 10amps absorb. ( To top balanced only)
So that means at 58.8v for 17 cells is 99.? % full.
I will monitor some more, and I might even set it lower yet.

 

[JimCraig]

I'm looking at the Magnum MS4448PAE Inverter/Charger. I'm building a system from the ground up. I've purchased 2 48v 5kwh lifepo4 batteries.
If I get the MS4448PAE inverter along with the ME-ARC, & ME-BMK, I still need to get a charge controller in addition to all that?
Plus it sounds like the ME-ARC only works well with the Magnum CC which is 900+.

If I still need a CC with the Magnum, this system is ending up being alot more than if I were to get a couple of the MPP LV6548 & with that I would end up with 12kwh. I need the 220v for my well pump. I ran a surge test on my pump & it only surged to about 13-14amps & settled in to about 7-8amps continuous.

Am I understanding everything correctly?
JC

 

[sunshine_eggo]

I'm looking at the Magnum MS4448PAE Inverter/Charger. I'm building a system from the ground up. I've purchased 2 48v 5kwh lifepo4 batteries.
If I get the MS4448PAE inverter along with the ME-ARC, & ME-BMK, I still need to get a charge controller in addition to all that?
Plus it sounds like the ME-ARC only works well with the Magnum CC which is 900+.

Welcome to Tier-1 hardware.

If I still need a CC with the Magnum,

You do. It's an inverter/AC charger.

this system is ending up being alot more than if I were to get a couple of the MPP LV6548 & with that I would end up with 12kwh.

Apples to Oranges. MPP is a lightweight inverter with little surge capability. The MS-PAE has true surge capability. Magnum are also the units that are still working 20 years after they're installed.

"12kwh" does not make sense. Maybe you meant 12kW?

What you're missing is that those MPP are power hungry monsters. They're going to consume 100W EACH just by being on with NO loads attached. That's 200W * 24h = 4.8kWh - almost 50% of your battery capacity just for the privilege of turning them on.

I need the 220v for my well pump. I ran a surge test on my pump & it only surged to about 13-14amps & settled in to about 7-8amps continuous.

Did you use the INRUSH function on a clamp meter, or did you just measure MAX? In most cases, the actual INRUSH is about 5X the run current. Well pumps are notorious for bringing inverters to their knees.

 

[JimCraig]

"12kwh" does not make sense. Maybe you meant 12kW?

Yes, 12kw. I was typing on the fly.

Did you use the INRUSH function on a clamp meter, or did you just measure MAX? In most cases, the actual INRUSH is about 5X the run current. Well pumps are notorious for bringing inverters to their knees.

I don't know. My son, who is an electrician, did the test. I'll have to ask him. Admittingly, he's not used to doing that kind of test. He's a newly Journeyman. I will check with him & redo the test. Thanks for the info.

Greatly appreciate the response & knowledge.
JC

 

[kampto]

I have a Magnum MS4024AE split phase output. Been solid for 14 years and it lives in a not so nice environment. Upgrading from Lead to LiFoPO4 25.6V/300ah this weekend. However I think my firmware is to old to set up custom battery settings. 99% of the time im using my Xantex MPPT 150/60 CC to charge batterys which does have custom settings. Will post my magnum findings later soon.

 

[Daddy Tanuki]

I have a 4448 and I set it for cc/cv 54.4 absorb controlled be end amps (20 amps) and no equalize using the AGS you can also set it for auto start by SOC if you have the BMS as well. I use Morningstar SCC’s to charge from solar. Tier 1 gear costs but it is less apt to let you down.

 

[jberger]

I have a Magnum MS4024AE split phase output. Been solid for 14 years and it lives in a not so nice environment. Upgrading from Lead to LiFoPO4 25.6V/300ah this weekend. However I think my firmware is to old to set up custom battery settings. 99% of the time im using my Xantex MPPT 150/60 CC to charge batterys which does have custom settings. Will post my magnum findings later soon.

You might want to ask Magnum if you can swap out your remote panel to get a version that supports LFP and full CC/CV.

 

[Ammo]

I

Glad it's working out for you Phil!

I ended up getting an updated ME-ARC that's running version 5.3 and has the LFP and CC/CV battery type profiles. Here's a screenshot from the manual with the default settings.

View attachment 83393

We've been up and running for a few weeks now and I'm happy to report another successful upgrade to lithium batteries using the Magnum inverter charger.

We didn't end up using any pre-charge resistor (no big sparks either) but we did add the ME-BMK module and have a much better gauge on everything from the remote. Really happy we got the BMK. The SOC from the BMK is way off from the reading from the battery's built in monitor so I'll have to do some work on that, but we use the voltage and AH readings to trigger the generator to kick on and off when needed.

We are using the CC/CV profile for charging. I'll post my profile here for anyone who might be working with similar battery specs or has any suggestions. Seems to be working well so far! I've made a few tweaks since I started and pretty much still obsessively keep an eye on things just to be sure.

These were the only battery specs I had from the supplier:

16S LiFePO4 Battery (48V 100AH)
Nominal voltage: 51.2V
Charging Voltage: 58.4V
Float Voltage: 54.4V
Charge current: 60A
LBCO (Discharge cut-off): 44V

I have 4 of batteries these in parallel to make a 400AH bank.

These are the settings I am currently using with the ME-ARC-50-L remote:

03C - Battery Type = CC/CV

Max Charge = 200 ADC
CV Charge Volts = 56.4
CV Charge Done = AMPs
CV Charge Done Amps = 25ADC
Max CC/CV Time = 6.0hrs
Set Recharge Volts = 50.8

03D Absorb Done = CC/CV Controlled
03E Max Charge Rate = 60% ~40A

Some other settings:
02B - LCBO - 48.0 VDC
Gen Run VDC - 49.6 - 53.6

I had to dial back the charge rate to 60% which is about 40A for my setup. I found the inverter/charger had a bit of a "hot and melty" smell when it was up around 60A. I'm going to keep it down in the "safe zone" since it's less stress on both the charger and batteries anyway.

We are running this system full time and have constant loads so my plan is to keep a close eye on everything and continue to make tweaks as needed. I'm aiming to manage charge cycles from 25% - 75% SOC and do a full 100% charge a least once per season. On paper (or in my head) that sounds good but in practice I'm not sure if that's realistic. Right now the winter sun seems to get us up to 90-95% pretty quickly (4hrs)

I'm open to any feedback and will check back if anything worth noting changes.

These batteries are literally a night and day difference for us compared to our old and very tired GEL batteries. We went from a heavy (winter season) dependency on the generator to now just occasional use for heavy loads and a top up charge.

Thanks to everyone posting here for sharing information and opinions. This thread has been super helpful!

* I updated some of the numbers. After I posted this I got paranoid and started reading more and decided to dial things back a bit further.

View attachment 83413

Im just changing my Magnum to LIFEPO. Your cut off amps is set to 25. If it was cloudy and your charge current drops wouldn’t it stop charging? Is there away around this. Or will it start back up when the sun comes out.

 

[jberger]

I think he's saying he has the Inverter's charger set to 25 end amps (cut off) and doesn't want to use much grid charging, hence the 5 amp input setting.
The PT charger will continue to charge as long as the SOC is below 100% and that's what he's using for everyday charging.
At least that's what made sense to me when I was trying to figure out why he set it up that way.

 

[Phil Orton]

At 51.2volts, or 3.2v per cell x 16, is the number, which I consider or want my cells to be my lowest.
I have grid power, so I use solar system during the day time for 12-14 hours (when it's high peek hours), and then it is set to standby mode for night time.
If anytime we have overcast for many days and the cells are getting low, the rebulk will go on at 51.2v and off at 52.6v, just enough charge to cover the loads and put the cells back up a bit. (Winter time only)
The solar system is there to save on hydro bill, so I do not charge the batteries with grid if I can. ( charger set for 5 amps input)
During the summer months ( 6-7 months) the grid is shut off and I'm offgridd completely, so the rebulk will never go on because there is no other source and the float mode stays on.
I have 2 magnum cc PT-100, so there's never a conflict, and
I also have another 24v magnum inverter with an outback fm60 cc, system in my garage and I haven't seen any problems.
The settings on your charge controller has to be the same as the inverter setup.


If you're using the LF280 AH cells, like I have, the resting charge amps should be set at 0.05C, which is 14ah per banks, if you're cells are at 3.65v each or 58.4v per bank.
My voltage is set at 55.2v per bank, so 3.45v per cell.
I have three banks of cells, two are eve LF280, tested around 271ah each cells, and the other bank are CATL 290 AH per cell. So by the time that the catl bank reaches 14 ah charge the other two banks will be close to 7 ah each, and as soon as the controllers sees 28 ah and under it will go to float mode, for the rest of the day.
If you set it to a lower level say 15ah, some of your banks will be charged to more than 95%
I'm still working on the system and I might even set it at 32ah, and see how it goes.

I have tried the SOC setting and I found that soc is not accurate on the magnum, let's say for example, you are at 100% most of the day and clouds comes in, and night, now you're at 80% the next morning, charging starts and then clouds for a few hours and then suddenly sunshine, the magnum will reset at 100% most of the time. But the actual SOC might be 10-30-40% off. And I've tried it on auto mode, 85%-95% it's all the same.
I have a Trimetric TM 2030A by Bogart Egineering, also monitoring and it is very accurate and doesn't mess up.
The best setting I find is on VDC, you monitor the voltage and you know where you're banks are at, approximately.

As I mentioned earlier, I used the SOC/BMK to control the charger but ran into a problem due to the SOC being inaccurate. While charging an EV overnight and expecting the charging to start at 30% the system completely shut down, both the inverter, then the bms's on 3 280kw 48v systems. Quite a pain to restart the inverter, charge controller, and bms systems. Had to lower the lbco on the bms's to show the charge controllers that 48v was available, and then reset everything from there. Have switched to using the dc voltages to start/stop the magnum charger. Good lesson but painful. Guess that's what DIY is all about. LOL.