Lithionic batteries uneven charging

[marktrofholz]

Our lithionic batteries are being charged by solar panels, and the battery status is 98, 85, 97.

Why is the middle battery lower than the front and back?

[John Dorrer]

44 minutes ago, marktrofholz said:

Our lithionic batteries are being charged by solar panels, and the battery status is 98, 85, 97.

Why is the middle battery lower than the front and back?

Mark,  I don't have the answer, but we experienced something that was similar

 When I would take the trailer back to the storage warehouse for 2-4 weeks, I would leave the solar on inside the building. I noticed a big difference like you. I remember having a phone conversation with Oliver. They suggested turning solar off while storing

 Next times and the battery discharge was within 1%.

 

Your situation is different.

 

I suggest you reach out to Lithonics technical support. They have always been helpful when I have called them

 Keep us posted.

 

[Shawna and Scott]

You might first want to check to make sure all the firmware is up to date. 

You might also check to make sure you do not have a loose connections on the battery. I had a similar situation and after updating firmware and talking with Oliver Service and Lithonics it turned out to be a loose connection. I basically unhooked all the wiring on the batteries and reconnected everything and all was good. 

Not saying that is your problem but it is an easy check.

[marktrofholz]

Thanks, will do.

[Roger]

Lithionics told me at the last rally that I should cycle the batteries. Discharge the batteries to their reserve voltage (i.e. until they quit working) and then recharge them. He suggested I run the a/c on battery until it quit as a quick way to run them down. This seems to have worked for me as my batteries now show similar life remaining. 

The rep said that the batteries don't really know their discharge state and use an algorithm based on recharge time, usage, etc. and sometimes get out of sync. 

There is another discussion about this here.

 

 

Edited December 9 by Roger

[DaveAndBecky_NorthernMI]

10 hours ago, Roger said:

Lithionics told me at the last rally that I should cycle the batteries. Discharge the batteries to their reserve voltage (i.e. until they quit working) and then recharge them. He suggested I run the a/c on battery until it quit as a quick way to run them down. This seems to have worked for me as my batteries now show similar life remaining. 

The rep said that the batteries don't really know their discharge state and use an algorithm based on recharge time, usage, etc. and sometimes get out of sync. 

There is another discussion about this here.

 

 

I have had same experience as Roger. The balancing process in battery charging works better after drawing them down to below 50%. I still see differences in SOC but less after draw down.

[Rivernerd]

20 hours ago, marktrofholz said:

Why is the middle battery lower than the front and back?

That State of Charge (SOC) differential is not a sign of damage to the battery.  Our three Lithionics batteries also discharge at somewhat different rates.    As advised by Roger above, periodic battery balancing is recommended by Lithionics.  This is done by discharging down to Reserve Voltage Cutoff (RVC) (until they automatically turn off), then back to full charge.  I have found that complete balancing after recharge sometimes takes 1-2 days on shore power before all 3 batteries show 100%. 

To discharge our batteries in the winter I run a space heater using the inverter (as I can't set the AC low enough in December in Idaho to get it to run).  The inverter will shut down 120V power when battery voltage drops to the point preset at the factory.  To get down to RVC, I then turn on a bunch of 12V loads, including all the lights and the refrigerator set to DC mode, for another couple of hours until the lights go out because the batteries have turned themselves off.  I can then reconnect shore power to charge the batteries back up to 100% SOC.  

This process balances all three batteries.  In my experience, the next time I use battery power, discharge rates among the three batteries are much more even, but never precisely the same.  That is o.k., per Lithionics.

[marktrofholz]

Wow. Thanks! Good info from you both about the draw down process. Will attempt it after making sure all connections are good.

[marktrofholz]

Well, I removed and reconnected all the battery cables, then did the power draw down to reserve cutoff.  Then I charged it back up to 100 percent.  They are all showing the same state of charge now. Lithionics rep did call me and told me of the need to periodically discharge  and charge to full in order to help the batteries keep their balance. He also said to charge with shore power to 100 percent before leaving on any trip as this helps the batteries maintain their equilibrium. Thanks for all the help!