question

Hi,

At 100%, the batteries are not that full yet that you really decrease longevity significantly.

And for the rest its inherent to the design: you’ll have to fully charge the batteries regularly to prevent imbalance between the cells. There is no other way; but besides that I wouldnt worry about this if I were you. Its all a bit on the theoretical side.

It might be useful to point out that the Victron Lithium cells don't use the same chemistry as Tesla. Not all "Lithium" chemistries are the same. Victron uses "Lithium Iron Phosphate" (Often abbreviated LFP) whereas Tesla uses "Lithium Nickel Cobalt Aluminum Oxide" (Often abbreviated NCA). You can read about the various chemistries here: https://batteryuniversity.com/learn/article/types_of_lithium_ion

LFP is a bit of a stand out in the Lithium battery chemistry crowd. Most of the other chemistries are fairly similar aside from LFP. Battery Univerisity describes LFP like so:

"Li-phosphate offers good electrochemical performance with low resistance. This is made possible with nano-scale phosphate cathode material. The key benefits are high current rating and long cycle life, besides good thermal stability, enhanced safety and tolerance if abused.

Li-phosphate is more tolerant to full charge conditions and is less stressed than other lithium-ion systems if kept at high voltage for a prolonged time. (See BU-808: How to Prolong Lithium-based Batteries). As a trade-off, its lower nominal voltage of 3.2V/cell reduces the specific energy below that of cobalt-blended lithium-ion."

So basically LFP is a lot more expensive than NCA, and doesn't carry as much energy per volume or weight... But LFP is able to tolerate being kept at near 100% charge without as much degradation as chemistries with higher operating voltages. It's still better to not keep it at 100%, but an LFP cell maintained at 100% will likely outlast a Tesla cell kept at 80%. I usually aim to keep my cells at 3.4v/cell rather than the "100%" charge which is 3.6v per cell. With LFP 3.4v per cell drastically increases service life and 3.4v/cell still gives you 95%+ SoC.

With newer cells, the specs might change, check with the manufacturer, on my batteries the data sheet specs are different and I have verified this with the manufacturer.