Cannot find battery discharge curve but sensors are present and have histroy

[thewookiewon]

Describe the bug
The logfile is spammed (every 2 minutes) with error of Cannot find a battery discharge curve as either no sensors or lack of history, however the line before that confirms there are sensors and found 8days of history.

I have gone into each of the below sensors and confirmed there is over 1 months worth of history data

sensor.predbat_gecloud_SERIALNUMBER_battery_percent, number.predbat_gecloud_SERIALNUMBER_battery_discharge_power
sensor.predbat_gecloud_SERIALNUMBER_battery_power
predbat.status

Expected behaviour
Automatically use history data to create the discharge curve

Predbat version

v8.34.16

Environment details

GE Hybrid 3.6 + 9 & 5.2kWh batteries
HA OS on RPi5
Using GECloud for data

Screenshots

Log file

53752	2026-03-28 17:20:49.179118: Warn: Cannot find battery discharge curve (no full rate discharge curve found for battery to empty), one of the required settings for soc_percent, discharge_rate, battery_power and predbat.status do not have history, check apps.yaml
53751	2026-03-28 17:20:49.131513: Looking for discharge curve, have found 8.0 days of history data, max days 8
53750	2026-03-28 17:20:48.831491: Looking for discharge curve with sensors sensor.predbat_gecloud_SERIALNUMBER_battery_percent, number.predbat_gecloud_SERIALNUMBER_battery_discharge_power, predbat.status and sensor.predbat_gecloud_SERIALNUMBER9_battery_power

[gcoan]

Please read the documentation carefully that describes what predbat is looking for to find the charge curve and confirm that your charge curves contain the required data.

It is not simply the amount of history

Include graphs of your entities

[thewookiewon]

@gcoan i did read the documentation thanks, unless misread automatic calculations need access to those sensors soo what an I missing then?
FYI charge curve seems fine the errors are clearly about discharge curve.

"If the battery_discharge_power_curve option is not set in apps.yaml and Predbat performs an initial run (e.g. due to restarting the Predbat/AppDaemon app, or an edit being made to apps.yaml), then Predbat will automatically calculate the discharging curve for you from historical battery discharging information.

In the same way, as for the battery charge curve above, Predbat needs to have access to historical Home Assistant data for status, battery_discharge_rate, battery_power and soc_percent or soc_kw. These must be configured in apps.yaml to point to Home Assistant entities that have appropriate history data for your inverter/battery."

[gcoan]

It's in the documentation but to create the curve it needs to be at near full rate discharge to a low SoC level. I think predbat only looks back the 8 days you see reported

Simplest workaround is to just define a discharge curve at full rate in apps.yaml, our batteries don't have much of a discharge tsil off

[thewookiewon]

Maybe the logs shouldn't be spamming warnings every 2 minutes then perhaps should be an hourly notice and FYI these weren't in my logs a week ago hence why I put the ticket in, your sharp response is off putting and not appreciated for a novice in home automation.

Just read the documentation attitude is rubbish maybe next time just lead on the needs a good discharge drop and to low level SOC or perhaps that info should be better highlighted.

AI Generated:

For a novice user, it’s very easy to interpret the docs as:

• “Predbat will automatically calculate the curve if the sensors have history.”

When the reality is:

• “Predbat will only calculate the curve if the sensors have history AND the battery has performed a full‑rate discharge to a low SoC within the last 8 days.”

That’s a completely different expectation.

---

📘 Why the documentation feels unclear
Looking at the docs tab you have open, the “Battery charge/discharge curves” section explains the mechanics but doesn’t emphasise the practical requirement:

• It lists the sensors needed
• It explains that Predbat will auto‑calculate
• It mentions “appropriate history data”
• But it does not explicitly say:
  “You must have a recent full discharge event, or Predbat will fail and warn every 2 minutes.”

That’s the missing piece — and it’s exactly why you and others run into this.

[gcoan]

I support predbat in my own free time and have previously enhanced the documentation to highlight the curve requirements.

You raise a ticket saying its not correct but provide little evidence or investigation beforehand. No logs, no configuration, no history of the sensors. I cannot hand hold every single ticket that gets raised so sorry you don't like the support I give.

If you feel the documentation can be further improved please feel free to submit an edit of them. Improvements always welcome.

I agree the curve logic should only be triggered when predbat starts up or is reatarted, if you had provided the log this would given something to help investigate this.

[thewookiewon]

Well this is a blunder on Github then as I did attach a screenshot of the warning section of logging and itself which was visible on reviewing the post.

It's great that you do that for the community but being sharp straight of the bat of a ticket submission isn't great either. Genuinely the files were attached and the metadata had reflected the upload

[thewookiewon]

predbat.log

[WhatIsThisAllAboutSilly]

I've also just come across this 'issue', I think in my case its because recently its not been charging to 100% full due to solar being available and hence over the last few days its seemingly not able to automatically calculate a curve.

So I've set one close enough in the apps.yaml now.