We've been parked now for nearly 5 months on shore power. Ordinarily, this means that our lithium House batteries would have been kept at 100% continuously. After we did our lithium battery install I asked Battleborn if there was an issue maintaining house battery bank at 100% when we weren't Boondocking. And, since we only occasionally Boondock, this would mean that our lithium batteries would virtually stay at 100%.
BattleBorn strongly recommended that unlike lead acid variants, lithium batteries should NOT be kept at 100% for extended periods of time. So, we occasionally turn our inverter's charger function off (inverter on) and let our house batteries provide all of our AC and DC current. Battleborn recommended letting the batteries run down to at least 80% periodically before recharging. The cycle count impact, they reported, was minimal from this type of cycling while protecting the batteries from being left at 100%.
If it's hot enough to need air conditioning, and you have soft start installed on your air conditioning, this process will take a much shorter period of time. If you're in cool weather and use high demand appliances only a few times a day this process might take significantly longer.
By setting a reminder on my phone, I can check the state of rundown periodically so I don't forget to recharge. Our system has a Victron Battery Protect module to ensure the batteries will not be harmed by shutting them down, even before the BMS would. And, because we have our generator connected through our Victron Cerbo device our generator would also start to avoid excessive rundown in the event that I forgot and left the coach unattended.
My 2 cents.
Good information, thanks for sharing what BB recommends.
Do you have a soft start installed on your A/C's?
Yes, two reasons.
With the switch referenced in previous battery post we can run either AC on battery or less than 50 amps. For example, at night in hot weather we run the forward unit. During the day we run the back unit. Keeps things quieter inside.
Second, extends life of new AC's by smoothing load into units at startup.
I was told the same thing by Battle Born. Since I have solar panels, I generally keep the charger off, which means the batteries regularly drop below 80% due to use at night, cloudy days, shaded sites, no electrical hookups at some locations, etc. If I see they are getting too low, I will turn the charger on long enough to bring them back up. It's not as exact as using a phone reminder, but it accomplishes the same thing.