Old Magnum Energy MS2000 Inverters with MS-MR controller

[richardhensley]

Hello,

In my RV I have 2 MS2000 inverter/chargers with MS-MR controllers. These devices are from 2011, so I think they are rev 0.8

Looking over the documentation, there is no LFP setting in this revision, however I notice the following settings are available for GEL, AGM1, AGM2.

I'm looking at PDF page 15, paper page 10 of this document at the table of battery types. The table is cutoff voltages.

https://www.magnum-dimensions.com/sites/default/files/MagArchive/64-0031-Rev-B-ME-MR-Manual.pdf

This is the manual for the inverter.

https://www.magnum-dimensions.com/sites/default/files/MagArchive/64-0007-Rev-A-MS-Series.pdf

The charging section on PDF page 46, paper page 40.

If battery voltage < 12.6 V, inverter goes into "bulk" mode. I don't know what that means in terms of voltage.
When the battery reaches absorb voltage, the inverter goes into "absorb" mode.
When the battery reaches float voltage, the inverter goes into "float" mode.
After some amount of time, the inverter goes into "full" charge model.

My question, does anybody know if I can use these devices to charge LFP batteries. Specifically, BigBattery or BatteryEvo LFP 12V

 

[Rumline]

I have (Edit: a slightly newer) inverter and remote, but they're functionally the same as yours. I can't definitively answer your question but I just came across this post which causes me concern: (click the "Click to expand" link to see the whole quoted post)

Renogy Lithium at 14.4 volts?

That is what they spec for the limit. I'm starting to think they are smoking the wacky weed at Renogy. Sorry for the terrible pic.

diysolarforum.com

The crux is that on non-programmable inverter/chargers that don't have a lithium setting, the absorption duration after a full charge is reached could cook the batteries:

The problem the GEL setting installation was the absorption DURATION, not the voltage. At 14.2V the absorption duration was 4 hours long with no way to change the length of the absorption cycle-timer. On top of a 4 hour absorption the chargers charge rate, which was very low in comparison to the banks Ah capacity, his cells were actually hitting 100% SOC before the voltage even got to 14.2V. Continuing to charge beyond the 100% SOC point can lead to lithium plating.

You may be able to upgrade just the remote to a more capable model which would support LiFePO chemistry natively.

 

[richardhensley]

I found out the answer today. My rev 3.7 inverter is capable of custom mode with an me-rc50 remote. And, I can use custom mode to charge lifepo4 batteries with a 2012 rev 3.7 inverter.

So, I just need to order the controller when I order my battery

 

[Rumline]

Nice! I'm glad you have a path to success.

 

[richardhensley]

More news on the MS2012 front.

You can buy the boards to upgrade from a 3.7 inverter/charger to the latest from a Magnum service center. Service centers can also upgrade your inverters, they say it takes about an hour. The service center I talked to quoted me $258 per board, plus tax and shipping.