What is normal behavior for an inverter charger?

HRTKD

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@Sojourner1 's experience is the same as mine. My AC-DC converter will keep my LiFePO4 battery bank at 100% or real close to it. Float is around 13.6v. I don't spend much time connected to shore power. But when I do, I often turn off the AC-DC converter and let the solar keep the battery bank charged.
 
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gcp

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@Sojourner1 's experience is the same as mine. My AC-DC converter will keep my LiFePO4 battery bank at 100% or real close to it. Float is around 13.6v. I don't spend much time connected to shore power. But when I do, I often turn off the AC-DC converter and let the solar keep the battery bank charged.
Thank you very much for adding your experience here. Looks like a number of you are configuring a float voltage for your LiFePO4 batteries, so I will try that today.

After some of the previous suggestions, I did the manual configuration for LiFePO4 batteries on my inverter/charger and set the Stop Charge voltage to 14.5 (instead of the 14.7 default) and the start charging voltage to 13.6 just to see what happens. That has kept the batteries consistently at 86% according to my Victron Smart Battery Shunt.

The interesting thing (to me) is that since doing this, my Victron Solar Charge Controllers are reporting producing very little to no power today (even though the sun is out). They're acting as if the battery is at/near 100% soc. I've made no changes to the SCC settings during this experiment with the inverter/charger.

To set a float voltage on my inverter/charger I will need to tell it that I'm *not* using lithium batteries. Can you anticipate that causing any problems?
 

Sojourner1

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If you're floating at 13.6v unplug from 120v if you're hooked up, turn the inverter on with a lite load and see if the Solar is covering that draw.

If you were charged up 14.5 & switched over to 13.6 your Victron might need to be resynced for 100% soc.
 

corn18

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If you're floating at 13.6v unplug from 120v if you're hooked up, turn the inverter on with a lite load and see if the Solar is covering that draw.

If you were charged up 14.5 & switched over to 13.6 your Victron might need to be resynced for 100% soc.
This is it. If the SCC sees 13.6V at the battery, it won't charge anything. That is 100% SOC for most SCC Li charge profiles.

Also, if your shunt is showing 86% SOC @ 13.6V, it is not synced properly. My shunt is out of sync right now and it always shows 100%. I haven't been to 100% SOC since it got cold, so I will live with it until spring. I guess I could charge it up to 13.6V and reset the shunt and then drain it back down to 70% for cold storage, but not really that important. I can read the voltage just as well as a shunt.
 
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gcp

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1E234394-1837-4EF4-B2A8-E20480F5068F.jpegThis is it. If the SCC sees 13.6V at the battery, it won't charge anything. That is 100% SOC for most SCC Li charge profiles.

Also, if your shunt is showing 86% SOC @ 13.6V, it is not synced properly. My shunt is out of sync right now and it always shows 100%. I haven't been to 100% SOC since it got cold, so I will live with it until spring. I guess I could charge it up to 13.6V and reset the shunt and then drain it back down to 70% for cold storage, but not really that important. I can read the voltage just as well as a shunt.
That makes sense.

The SCC is seeing 13.9. The shunt is showing a voltage of ~13.9 at 86% charge. Here’s a link to my victron VRM dashboard with real-time data:


And here’s what both of SCCs’ parameters are configured as:
1E234394-1837-4EF4-B2A8-E20480F5068F.jpeg
 

gcp

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This is how the smart shunt is configured:
887C18F5-1BE7-46A3-819C-4BC7BA66ADFE.jpeg
 
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gcp

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If you're floating at 13.6v unplug from 120v if you're hooked up, turn the inverter on with a lite load and see if the Solar is covering that draw.

If you were charged up 14.5 & switched over to 13.6 your Victron might need to be resynced for 100% soc.
Oh that’s interesting. I just tried unplugged and put a lite load on the inverter, and the array never jumped in to supply power. That’s not what normally happens for me.

6AA9745D-1A6A-40F9-8B1F-543F893B016D.jpeg
 
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gcp

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Here's the latest configuration based on folks' recommendations here:

Power Sources:
Shore Power (30A): Plugged in
Solar Array (740W): Enabled (but sun is setting now)

Renogy Inverter Charger:
Config Profile: Manual
Battery Type: Non-LiFePO4 (This is the only way it will allow me to set a float voltage)
Float Voltage: 13.6
"Boost" Voltage: 14.5v

2x Victron SCCs:
Battery Preset: LiFePO4 12v
Absorption Voltage: 14.2v
Float Voltage: 13.5v

Victron SmartShunt:
Capacity: 340Ah
Charged Voltage: 14.4v

Dashboard snapshot as of this posting:
IMG_CC38ACC618CA-1.jpeg

Link to realtime VRM dashboard:
 

gcp

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If you're floating at 13.6v unplug from 120v if you're hooked up, turn the inverter on with a lite load and see if the Solar is covering that draw.

If you were charged up 14.5 & switched over to 13.6 your Victron might need to be resynced for 100% soc.
You were absolutely right.
 

gcp

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Thank you all for helping me sort this out. I believe my initial concern has been addressed.

Telling the Inverter/Charger to treat the batteries as a custom configuration with float voltage specified, and recalibrating my smart shunt is now keepings the battery bank charged while connected to shore power. During the day, solar power seems to take over and batteries are kept at/near 100% by the SCCs.
 
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