Salvo wrote:
The controller does not control current. It doesn't care what the current is.
The charge controller (CC) controls voltage. But I don't believe the CC regulates voltage at 14.40V (as you think) just prior to the voltage surge. The CC is in boost mode, which means the charging battery current will cause battery voltage to rise until max boost voltage is achieved (14.8V). With the inverter load, there's more or less an equilibrium at 14.4V, preventing battery voltage to rise. As your first video shows, this equilibrium isn't maintained. All of a sudden all hell breaks loose and we see the battery surge to 14.8V. The CC does what it's supposed to do, that is charge to 14.8V and then drop to a lower voltage (absorption mode).
I've asked you to do a simple test that will tell us whether the inverter turning off is the cause or the effect of the current surge. That would be the number one objective. Only through further testing will we understand how to fix your problem.
Sal
I missed the bottom of page 11 posts, sorry.
Sal, the situation is as smkettner explains in the post following your's above. There is a single setpoint for bulk and adbsorption charging and it is currently set at 14.40V. At the start of my troubleshooting it was at 14.60V and I have been trimming down ever since.
It may not have been clear in the first video clip, but what is happening to cause the voltage spike is just as you stated in an earlier post.
Salvo wrote:
....Spikes are usually generated when inductive loads are turned off....
I think you are under the impression that the voltage rise/spike is occurring at random. It is not, it occurs only when I remove a load from the inverter and I think this fits your definition of a "spike." The case of the video clips, I am unplugging my laptop AC charging cord while I'm using to power the laptop.
My controller says the controlling current IS what it does during absorption. Isn't it trimming the current (duty cycle?) so that battery voltage remains at the absorption setpoint? Quote from the Morningstar Tristar manual
"2. PWM Absorption: When the battery reaches the regulation voltage, the
PWM begins to hold the voltage constant. This is to avoid over-heating
and over-gassing the battery. The current will taper down to safe levels as
the battery becomes more fully charged. The green LED will blink once
per second."
Also from
Morningstar: Why PWM? document:
"When in PWM regulation, the
current from the solar array tapers according to the battery’s
condition and recharging needs."
