State of Charge on Lithionics Batteries

[Jps190]

Does anyone with the 3 130AH Lithionics batteries ever see a different SOC between their batteries. I have one battery that always seems to be different than the other 2 even though it is showing similar voltage.

[John E Davies]

I can’t comment on that brand, but the Battle Borns need to be fully charged to 100% so that the individual batteries can balance with each other - current flows from one to the other until their state of charge matches. I suspect that is true for yours, have you taken them all the way to 100% to see what they show after a day’s rest? Again, the following info is NOT for Lithionics, but they may be a very similar recommendation:

“As for balancing the lithium-ion batteries, we typically expect them to be charged up to 14.4V as that’s when the passive balancing mechanism kicks in. If you’re floating at 13.6V, there’s no balancing happening and you’re not going to balance the cells until you charge it up to around 14.4V, or at least 14.2V. This won’t be required if you’ve got a solar charge controller or if you have a battery-to-battery charger for alternator charging. These devices can accommodate 14.4V on every charge, so you don’t need to worry about it.  

If you don’t typically charge at up to 14.4V your cells may get a bit out of balance because of temperature extremes or larger loads. To rebalance your system, we recommend being able to charge it up to 14.4V once a month or even once a week. Please note that it depends on your system usage. You may not notice anything, but if the batteries are hitting high voltage disconnect sooner than you’d expect, for example at 14V, or if they’re hitting low voltage disconnect sooner than you’d expect, such as at 11.5V , then you may want to think about rebalancing the battery cells internally and all you must do is charge it up to 14.4V in order to rebalance the cells. “

https://battlebornbatteries.com/understanding-lithium-ion-getting-started-with-your-battle-born-batteries/

John Davies

Spokane WA

[LCTraveler]

Greetings from Washington state.

I have the 3 130ah batteries in our Oliver and I have seen pretty much the same thing you have on the phone app. The fact that the voltages are the same tells me your batteries are fine. 

lithionics has admitted that the percentages shown are not always as accurate as we would like. A few things they recommended I do has helped the app SOC to be more accurate though.

I updated to the latest firmware for the BMS. This can be done in settings on the app. Make sure your phone has good Wi-Fi connection when you do this because the battery bms needs to go out on the lithionics site and get the correct firmware. 
Next I drew my batteries down until they shut themselves off. This is called the reserve voltage cut off. Then I charged my batteries to 100% or 14.2 volts. 
This seems to have helped make the % state of charge numbers more accurate.

Hope  this helps,

Mike

 

[Jps190]

Thanks guys.  I really haven't "used" the batteries very much yet.  I'll go ahead and run them down to RVC and the give them a full charge to see what happens.

 

John