I just finished my installation of 2 x 100Ah lithium batteries on my sailboat. They are charged with Victron Blue Smart, Victron Orion DC/DC and Victron Smartsolar 100/20.
And now my question. When connected to the Smartsolar and almost full batteries but not in absorption yet, my batteryvoltage jumps to 16v and back for a while. It settles when the charger goes to absorption. The Smartsolar is set to default Lithium settings.
What do I change in the settings to resolve this?
Your Lithium batteries are imbalanced internally, i.e., one or more of their individual cells has hit the upper limit, and the BMS has cut the battery out of the charge circuit.
When the battery is cut out of the charge circuit, the MPPT voltage spikes because it can't stop it's output fast enough to prevent it.
It is very common for new batteries to be imbalanced due to time elapsed between manufacturing and receipt and hazmat shipping requirements to ship them at reduced state of charge.
Recommend you override the defaults with:
These should reduce/eliminate the spikes and give the BMS more time to balance the cells.
Try resetting to the defaults in 1-2 weeks. If it still spikes, return to the above settings.
