In the last 2 weeks I have noticed odd charging behaviour when my Powerwall is in time based mode, compared to the previous behaviour 2021 through 2023. Any one else care to check their data, or ideas what is going on?
First some details of my use. While I have solar panels, my Powerwall usage includes charging from the grid during the low solar generation winter months. Tesla's prediction algorithms fail to manage Powerwall charging in the way I want. I have tried letting time based mode run the show, setting the prices etc., and it makes inefficient decisions (based on historic data) and costs me money. The coastal weather here is unpredictable as is our household use, so my local knowledge and intelligence are superior to any so called "AI". Hence I manage charging from the grid when I need it using scripts that adjust both mode and backup reserve percentage at the start and end of my 4 hour over night period of cheap electricity supply.
When I need more power than 4 hours at 1.7kW that self-powered gives I switch to time based for that period to get the higher 3.6kW rate (throttled in UK systems with official permission needed on installation to get the full 5kW).
Charging typically looks like this:
You see charging from the grid start at 12:30, ramp up quickly to 3.6kW and then drop off once the desired reserve percentage has been reached (it would stop at 4:30am if this was not done). My graphs consistently look like this for winters of 2021 through to end of December 2023. On colder nights (we rarely get below freezing) there is a gentle ramp up to the full rate which I assume is temperature related.
But in the last couple of weeks it does erratic things like this:
Yes in that case it did get to the 100% in the period, but what is it doing?
Other days It has failed to reach 100% having throttled the rate to a mere 1.7kW despite being in time based mode.
Clearly I had internet access to the cloud as charging from the grid started and stopped (so the backup reserve percentage was changed). The weather over night was no lower than 6C. The firmware has not changed since September 2022 (version 22.18.5).
What I would like most is self-powered mode to provide charging at 3.6kW, an improvement I was told by Tesla Support was coming back in November 2021. After all even their FAQ claims that 3.3kW is the optimum rate for the battery life. However having charging in time based behave erratically is a turn for the worse.
I can only assume that during "autonomous" time based mode the charge rate from moment to moment is managed from the Tesla Mothership, and that for 2024 they have changed the strategy so it no longer always uses the 3.6kW rate to get to the reserve percentage. This is bad news fore me - I only have 4 hours at cheap rate in which to charge my Powerwall.
@auxms75d how does this compare to your recent experience mentioned in the firmware version thread?
First some details of my use. While I have solar panels, my Powerwall usage includes charging from the grid during the low solar generation winter months. Tesla's prediction algorithms fail to manage Powerwall charging in the way I want. I have tried letting time based mode run the show, setting the prices etc., and it makes inefficient decisions (based on historic data) and costs me money. The coastal weather here is unpredictable as is our household use, so my local knowledge and intelligence are superior to any so called "AI". Hence I manage charging from the grid when I need it using scripts that adjust both mode and backup reserve percentage at the start and end of my 4 hour over night period of cheap electricity supply.
When I need more power than 4 hours at 1.7kW that self-powered gives I switch to time based for that period to get the higher 3.6kW rate (throttled in UK systems with official permission needed on installation to get the full 5kW).
Charging typically looks like this:
You see charging from the grid start at 12:30, ramp up quickly to 3.6kW and then drop off once the desired reserve percentage has been reached (it would stop at 4:30am if this was not done). My graphs consistently look like this for winters of 2021 through to end of December 2023. On colder nights (we rarely get below freezing) there is a gentle ramp up to the full rate which I assume is temperature related.
But in the last couple of weeks it does erratic things like this:
Yes in that case it did get to the 100% in the period, but what is it doing?
Other days It has failed to reach 100% having throttled the rate to a mere 1.7kW despite being in time based mode.
Clearly I had internet access to the cloud as charging from the grid started and stopped (so the backup reserve percentage was changed). The weather over night was no lower than 6C. The firmware has not changed since September 2022 (version 22.18.5).
What I would like most is self-powered mode to provide charging at 3.6kW, an improvement I was told by Tesla Support was coming back in November 2021. After all even their FAQ claims that 3.3kW is the optimum rate for the battery life. However having charging in time based behave erratically is a turn for the worse.
I can only assume that during "autonomous" time based mode the charge rate from moment to moment is managed from the Tesla Mothership, and that for 2024 they have changed the strategy so it no longer always uses the 3.6kW rate to get to the reserve percentage. This is bad news fore me - I only have 4 hours at cheap rate in which to charge my Powerwall.
@auxms75d how does this compare to your recent experience mentioned in the firmware version thread?