Should I care about re-balancing lithium battery cells? Issue resolved

LauraC

If I stopped giving a #$% about re-balancing my lithium battery life would be much easier.  I recall the ease of my lead acid battery - the only maintenance it needed was to take it in the garage and put it on a tender in the winter.  Ah, the good old days!  Now, Battleborn insists the voltage get to a certain level and stay there for a certain amount of time to "re-balance" to ensure long battery life.  They can't be charged below freezing.  Can't be outside below minus 15 degrees. Etc. Etc.  It's like the care and feeding of a child.  Anyway, I thought I was winterized - but it's been bothering me that my 100 ah BB battery has likely not been rebalanced since mid November.  Here's a post I put on Will Prouse's DIY Solar forum.  It's gotten no responses - probably because my question is beneath the solar inteligencia over there.  

I have a one year old 100 ah Battleborn battery in my small camper. I monitored all summer to make sure the cells rebalanced - I was getting 14.4 v for 18 or more minutes on a regular basis with solar from 2 190 watt rooftop panels and a 140 watt Zamp portable. In October the camper began sitting on a dealer lot waiting for repairs - until mid December. Per SmartShunt it got down to 12.79 v in mid December. I bought a Victron IP 65 to get it to full charge on shore power at my house because I have a WFCO charger/converter that will not keep the voltage high enough for long enough to re-balance. I had a BB tech on the phone with me while charging to confirm I was doing it right - because first try it only showed that I got to 82 percent charge per Smart Shunt. (the tech's solution to that was to change the discharge floor from 5 percent to zero)  The IP 65 charged to 14.2 v (12/18/25) for only about a second then steady drop in voltage to 13.3 where it is now - holding pretty much steady. The last full rebalance was in mid November when the sun was probably strong enough while it was on the dealer lot to get to 14.4 for 18 minutes or so. I was expecting the IP 65 to get it into absorption range for at least 18 to 20 minutes to rebalance the cells. Instead, it hit 14.2 and dropped like a rock. I have attached two screenshots - of the 14.2 peak on Smart Shunt and Smart Shunt settings. The IP 65 charge settings provided to me by BB are as follows: absorption v 14.4, float 13.6, storage 13.6 and 15 A charge current. Question - should I care or do anything about the apparent lack of absorption range re-balancing? Given the saga with BB I am leaning toward just replacing the battery with a LiTime 12 V 230 ah Bluetooth lithium before camping in the spring. It has twice the capacity for half the price of BB. And probably no overheating terminals. Thanks for reading this and any thoughts!

Horigan

I personally wouldn't worry about it.  LiFePO4 batteries provide thousands of full charge/discharge cycles.  Many more with the partial cycles we typically impose.  Even if you lost 25% of the battery life due to not getting to full charge for balancing, you wouldn't notice the difference in the time you own the trailer.  I'd focus more on the capacity.  If you would benefit from the increased capacity, go for the bigger one and sell the BB.

LauraC

Thanks Horigan.  Well, I was able to get the battery re-balanced this morning.  It occurred to me that the WFCO might be interfering with the IP 65.  Sure enough.  I kept the camper battery switch in the off position so the WFCO had no power.  I plugged the camper into our house outlet and plugged the IP 65 into a 110 v outlet in the camper.  The IP 65 then allowed a charge in absorption (rebalancing) range of 14.26 v for 30 minutes.  I then re-set the SOC to 100 percent, unplugged the camper and IP 65 and the battery can just rest for the winter.  I feel better getting that done - even if there's no need to re-balance the cells.  I probably will go for the larger battery.  But in the meantime, my BB is healthy.

Maxcamp

Agree with your concerns about maintaining these expensive batteries.  .  Isolating from WFCO was clever.  You got it right.  Battleborn sold us our IP65 charger at same time as batteries and it does great.  
We charge one isolated battery at a time, not hooking up to whole bank.  This is at suggestion of BB. 

 Circuit breakers on every terminal connection.make our maintenance easier.
Nucamp wires in a 30a fuse on each positive terminal.  Many others' photos show no disconnect means.