battery checkup

A few days ago I noted the tall conifers were impeding my ability to get a full charge on the SLAs.    I ended up setting Vfloat == Vabs to get more absorption time and let endAmps drop further.


After four charging days of eternal absorption **endAmps finally fell back down to normal levels **and was still dropping slowly.  This suggests (but does not prove) there was no permanent loss of capacity.

I’ll keep the controller configged this way for the near future to see what happens.     I do not have the option (or desire) to upgrade to a top-tier controller with serious endAmps monitoring.  The mid-range Victrons’ adaptable absorption feature is reported to get confused with “false sundown” events and can short-stroke Absorption.  Then I’m in the same situation only with less money.

my WAG (wild ass guess) about what was going on

In general,

  1. Slow charging extends Bulk and truncates Absorption.   In my normal open-air camping the somewhat overpaneled system (2:6:1) starts making power quite early.  there’s not a lot of power available at those solar angles, but it’s something coming in rather than nothing.  I think this slow, gradual charging was making for short absorption that fit in the 180min window.

  2. Fast charging  makes for quicker bulk and longer absorption.  In this case the sun was largely blocked until it was quite high in the sky, about 11am.  Bulk was shorter and Absorption would have been longer but it was chopped off by my controller’s 180min max.