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.
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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.
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