Predbat, the open-source battery and solar prediction tool used with home energy management systems, released version 8.55.0 on 7 September 2026. The release notes list the changes as "Improve plan history view, Improve PV clipping, Bug fixes"1. A separate entry dated the same day records "Tesla alternative optimiser, bug fixes"1.
The release extends the manual rate override horizon to seven days, according to the release summary. The plan history view and PV clipping predictions are both listed as improvements in the same entry1. PV clipping predictions relate to periods when a solar array generates more than the inverter can convert or the battery can absorb, so the forecast of lost generation changes.
The same release notes carry a set of fixes for specific inverter and cloud integrations. These include a fix to GivEnergy auto-config so that it respects site export limits, a diagnostic log of the Octopus Intelligent Go dispatch timeline, and a change to Teslemetry that signals a tariff-based Time-Based Control mode so that Opticaster runs the charge at full rate1. A warning is added for a moderate inverter clock skew of 5 to 29 minutes1.
"Improve plan history view, Improve PV clipping, Bug fixes"
Later entries in the same release feed, dated 10 and 15 September 2026, record further work. The 10 September entry is listed as "FoxCloud FeedIn First, GECloud 3-phase fix, Misc bugs & docs"1. The 15 September entry is listed as "GivTCP REST is now a component, Octopus fixes, Misc"1. That entry also adds a configurable number of retained log files and a manual_soc_max setting described as a discharge-direction ceiling sibling to manual_soc1.
The release feed does not state which inverter brands or cloud services are supported by the 8.55.0 changes beyond those named in the individual entries, and no installation figures or user numbers are given1.
Why it matters for households
Predbat sits between a home's battery, solar inverter and tariff data, and decides when to charge or discharge. For a household, the practical effect of a better plan history view is that past decisions can be reviewed against what actually happened, which is the basis for judging whether a battery is being used as intended. Improved PV clipping predictions affect how much solar generation the plan expects to be usable rather than curtailed, which feeds into the charge and discharge schedule.
The seven-day manual rate override horizon matters where a household's import or export prices are known further ahead than the tool previously accepted, for example where a fixed-rate period or a known tariff change is coming. The integration fixes, including the GivEnergy export limit correction and the Octopus dispatch timeline log, affect homes running those specific systems. The clock skew warning addresses a known cause of scheduling errors, where an inverter's clock drifts from real time.
No detail of the vulnerability is given in the release feed1.
What happens next
No further dated steps are given. Households running Predbat alongside a home energy management system would see these changes through their existing setup rather than a separate product.
Sources1 cited
- [](https://github.com/springfall2008/batpred/releases.atom), github.com