Lithium charge level between trips

PeterTAB

We just picked up a 2024 TAB 400 with 100ah lithium and 310w solar and took it out on our first trip. At the end of the trip when we got back home, the battery was back at 100% due to charging from the TV and the solar.

I've heard it's not great to store lithium at 100% long term. We expect to go on trips once every month or two. Will it hurt the battery to leave it at 100% for that long?

Alternatively, what are some good ways to limit charge level? Disconnect the battery as soon as I wake up the morning before we come home? Wait until we're home and run down the battery a bit at night time, like turn on the fridge for a few hours? Any tricks with the victron software? How do others manage this?

Thanks!

Horigan

I wouldn't worry about the 100% charge during camping season.  During the winter you can deplete the battery to about 50% charge via the refrigerator and having the Victron solar charger being turned off via the phone app.  Depending on which refrigerator you have, it may take a day or two to get the battery down to 50%.  If you have an inverter, you can run it down faster, but would need to monitor whatever device you plug in to draw down the battery. 

In reality, I doubt you would notice a difference in battery performance over time if you just let it sit at 100% all the time.  What does the battery manufacturer recommend?

elbolillo

Herre is a link to a blog post from Battleborn: https://battlebornbatteries.com/faq-how-to-winterize-your-batteries/

In a nutshell, they recommend charging 100% and then disconnecting for long-term storage.

gkreitzburg

I figured our 2023 was sitting on the lot for a year and a half when we bought it in december. Pretty sure they didn't do anything but let it roll. still need to use it a few times to figure out how long the battery lasts with usage - our first trip was disappointing with the heat cutting out at 5:30 AM - but I didn't know to make sure the battery was fully charged at the start (assuming with a three hour drive it would be).

PeterTAB

Thanks for the link! It is indeed a Battleborn, and sounds like they are fine to be stored at 100%. There is a comment thread where they provide some more details:

Chad asks:

All other Lipo4 battery brands say not to store them at 100% SOC , most say below 70 % but above 30 to keep them from going dead… Why do you all say 100%, do they not build heat like others ? that breaks down the battery overtime ?

Battleborn replies:

Hi Chad. Unlike other LiFePO4 batteries that use prismatic cells, our batteries contain cylindrical cells. This means there is no worry of damaging the battery by fully charging or discharging it. Additionally, these cells are top-balancing, meaning once the batteries is fully charged the cells are balanced, this is why we recommend fully charging our batteries before storage. This way the cells are balanced during storage and fully charging the battery also allows the longest storage time.

SLJ

"Disconnect the battery as soon as I wake up the morning before we come home?"
Just an FYI from your original comment, the battery needs to be on when towing as it supplies the emergency brakes on the camper with power. Do not tow with the battery shut off.