Xantrex Technology Link 1000 - Manual (Page 53)

Charging Functions
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Over-charge Ah (Accumulation of Positive Ah)
If the battery is 100% charged, and the Link 1000 is
synchronized with the battery, over-charge Ah are displayed
as a positive Ah number. Some accumulation of over-charge
Ah is normal with systems that are continuously connected to
a charger. For example, a 100 Ah battery at Float voltage will
normally have a little less than 0.1 amps flowing into it. This
means you would expect about 2.4 Ah of over-charge to
accumulate each day. If your battery system is larger, more
current flows and more over-charge Ah accumulate.
If the charging system is a constant voltage type set at 14.2
volts, as much as 1 amp may be flowing all the time after the
battery has reached the charged parameters. Prolonged high
voltage applied to a fully charged battery will likely cause
gassing, and you would expect to see a large Ah over-charge
every day. This is a indicates that you are shortening the life
of your battery by over charging. Check your Link 1000
before turning off a charging source to see that you have not
accumulated too many over-charge Ah. (When discharging
begins, the Link 1000 resets to zero and begins to report Ah
consumed.)
If you equalize your batteries, some over-charge Ah will
accumulate. This is normal and ensures that the Link 1000
stays synchronized with the battery state-of-charge.