Electrical question and lithium

[Bill and Nancy]

If I understand this correctly Im supposed to run the batteries down to LVC and re charge them every 6 months. If this is so does anyone have a recommended procedure and how I should discharge them (ie run an electric heater) and how do I know  when they are at LVC. The other question is why is the Norcold refrigerator not connected to the inverter?

thanks

Bill

[John E Davies]

2 hours ago, Bill and Nancy said:

The other question is why is the Norcold refrigerator not connected to the inverter?

It would waste your battery to invert it, due to efficiency losses in the equipment, the fridge already runs on battery, so the only time it benefits is when you are connected to a 120 volt ac power source.

John Davies

Spokane WA

[DaveAndBecky_NorthernMI]

You can use Lithionics app to monitor voltage during discharge. If you have solar you'll want to disable solar charging using red switch in streetside upper cabinet above bed.

[Geronimo John]

I am a new Litho user so this is my dumb question(s) response:

The idea of draw-down and recharge past "Resting Full Charge" on to equalization level is to ensure that all the cells are "together" voltage wise.  For our Battleborns (3 Each 100AH = 300 AH Total), and charging at 60 amps, I was advised to charge up to 13.7 (RFC) and continue charging with our Progressive Dynamic's 60 amp charger for 30 minutes/ battery = 90 minutes.  It will peak out at 14.7 and stay there for the equalization process.  At that point, shut off the charger and it will settle back to RFC of 13.7 volts and all cells will be at that voltage allowing use of 100% of the installed batteries.

The idea is to over charge for equalization purposes periodically.  

Bill's question and responses above went "Tilt" in pea brain so, I can't help but ask:

• Is there a reason to take it all the way down to the Low Voltage Cutoff (LVC)? 

• Wouldn't just say 30% Status of Charge (SOC) do just as well?   

GJ and other new Litho's are a pondering......

[Rivernerd]

On 3/30/2023 at 7:04 AM, Bill and Nancy said:

If this is so does anyone have a recommended procedure and how I should discharge them (ie run an electric heater) and how do I know  when they are at LVC.

I turn on all the interior lights, along with the inverter, and run a space heater plugged in to a 110V receptacle. 

You know when you have reached Reserve Voltage Cutoff when the space heater and the lights go off.  This means the BMS in the batteries has done its job by turning off the batteries before they get fully depleted.

Once the lights go off, it is time to unplug the space heater, ensure that the inverter is off, turn off the master light switch, and reconnect shore power to recharge the batteries.  You can then leave shore power connected for another 6 months, or until you put the trailer back into regular use.

Hope this helps.

[CnC]

13 hours ago, Geronimo John said:

Low Voltage Cutoff

In five years of using Battleborn lithium, we have never taken our batteries down to their bottom settings on purpose.  They did go "dead" once while boondocking and we had to plug in our portable Yeti 1000 (emulating shore power) to initiate the internal BMS. 

This is from BB's blog: 

"Some batteries, including Battle Born batteries, have a low-voltage disconnect feature built into the BMS. This is a safety feature designed to protect your batteries and help ensure they last as long as possible. The low-voltage disconnect mode typically kicks in when a battery reaches 10V, and it’s important that you charge your battery as soon as possible. Within five days is best.

The only way to get a battery out of low-voltage disconnect mode is by resetting it, which means charging it. You’ll need to plug into shore power or alternator power or get a charge from solar panels. If you can, charge them back up to 100% and allow the batteries to balance all of the cells."

 Charlie.

[Mike and Carol]

We don’t run our Battle Borns down either.  I’ve had them down to 50% a couple of times but usually they don’t go down below 70% before they get some charge.  Mike

[Geronimo John]

5 hours ago, CnC said:

In five years of using Battleborn lithium, we have never taken our batteries down to their bottom settings on purpose. 

5 hours ago, CnC said:

"Some batteries, including Battle Born batteries, have a low-voltage disconnect feature built into the BMS.

1 hour ago, Mike and Carol said:

We don’t run our Battle Borns down either.  I’ve had them down to 50% a couple of times but usually they don’t go down below 70% before they get some charge

Mike and CnC:  Exactly my thoughts and procedures as they echo the Battleborn guidance. The intent of my post was to get just such feedback. 

That said, the advice and procedures stated are only for OUR Battleborn based systems.  Other manufacturers have their procedures to be followed.  The very reason it makes sense (as all three of us did!)  to always state what battery manufacturer and size/model we are talking about.  Especially for Lithionics that vary quite quite bit from Battleborn, especially in the topic of cold weather unattended storage requirements.  .

GJ