Limiting Litium battery charging

DIY
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1

Battery…Victron Superpack 200Ah x 2
Charger…Phoenix 12V/ 50A-1
Charger…Smartsolar MPPT 100/30
Charger…Orion 12/12-50A DC-DC
Smartshunt 500A

I would like to limit charging of the battery to maybe 80% or at the most 90%, when I plan to have the RV resting for a while (1 month or more).

I am thinking if I adjust the tail current to a higher number than todays 0,5%, maybe I can fool the charger to think the battery is bull before it is. It would read 100% charged, but will be lower, how much depending on the tail current number.

So my question is…do the charging stop when tail current is reached, and is adjusting the tail current a way to go?

2

The best way to limit maximum SOC with lithiums is to trim down the Absorption voltage by 100mV or so, rather than trying to play with tail currents.
Regulating the high voltage end of the charge cycle has the effect of limiting the rate of internal corrosion, so reducing this voltage slightly helps prolong the life of the cells.
SOC is a secondary or calculated parameter for a battery, rather than a measured physical value like cell voltage. Also Lithiums don’t need a repeated absorption cycle in a storage charge mode, but could quite happily be left on a 3.3V per cell (13.2V for a 4 cell pack) float charge.