radian battery settings

[wtfg]

I had a Skybox for a year before Outback replaced it with a radian 8048
When I would force a charge it would go to the Absorb charge setting and stop charging, unless I had the absorb time set
If absorb time was 10 minutes it would reach Absorb and charge for 10 minutes

My radian if a force a charge it only charges to what I have the absorb time set too
if I set it for a hour it will go past the Absorb setting until the hour total charge time is reached
If I have Absorb time set for 15 minutes, it quits charging after 15 minutes and never reach Absorb charge setting

Doesn't seem normal to me
Thanks

[raysun]

The description seems odd indeed.
Perhaps post a screen shot of the Radian Battery Charger parameters?

Also, updating your profile with the current configuration and exact battery details would be helpful.

Seeing as there appears to be AC coupled inverters in the mix as well, describing how they are configured in the system may help get to the bottom of things.

[wtfg]

Here are my Radian settings

[Mike Curran]

This application note https://outbackpower.com/downloads/docu ... radian.pdf describes some special programming that's needed when AC-coupling to a Radian. Maybe your answer is in there - I'm no Radian expert.

[wtfg]

I did the software update for AC coupling on the Mate3 and Radian

[raysun]

if I set it for a hour it will go past the Absorb setting until the hour total charge time is reached
If I have Absorb time set for 15 minutes, it quits charging after 15 minutes and never reach Absorb charge setting

A small point. The Absorb Time setting is in 0.1H increments, so 6 minutes, 12 minutes, 18 minutes, etc.

54V is pretty low charging target for a 16S LFP. Is this an attempt at a maximum state of charge around 75-80%?

The normal charge behavior is a Bulk (Constant Current) stage until the Absorb Voltage is reached at which point an Absorb (Constant Voltage) phase is executed for Absorb Time. The setting of Absorb Time has no impact on the Constant Current (Bulk) phase, however, the time to reach the Absorb Voltage can vary with battery State of Charge at the time the charge cycle begins.

Is there another charging source (e.g.: the AC coupled inverters) that is driving the battery voltage above the Absorb Voltage value?
Is the Radian calibrated to the battery voltage? (IIRC, the internal voltmeter resolution is +/-0.4V).

[wtfg]

It seems like mine stays in bulk for one minute than switches to absorb
From my event notification

[raysun]

It seems like mine stays in bulk for one minute than switches to absorb
From my event notification

OK. That would seem to indicate the battery is reaching 54V after a minute. Can you confirm when that voltage is reached?

[wtfg]

It seems so
Ill raise the absorb to 56 and try charging again, and watch the process

The reason I messed with the absorb setting was because my BMS was bad it was dropping 2.5 volts across the solenoid randomly causing Radian to charge
And I didn't want to overcharge the batteries
I replaced the BMS Sunday

[raysun]

While charging, my LFP is at 75% @ 54V, and 99% @ 56V.
Try -
Absorb Voltage: 56V
Absorb Time: 0.1H

[Mike Curran]

This is off topic and it certainly looks like Raysun has you covered, but I just had to ask, are you using a relay to disconnect your microinverter array in order to control battery charging? Because a Radian set up for AC-coupling will do that for you without the need for a relay. Just sayin'...

The reason I messed with the absorb setting was because my BMS was bad it was dropping 2.5 volts across the solenoid randomly causing Radian to charge
And I didn't want to overcharge the batteries