Add an extra GivEnergy battery — hybrid & AIO expansion guide
Your GivEnergy inverter supports multiple battery units — but the expansion process involves more than physical installation. This guide covers model-specific limits, battery generation compatibility, CAN bus wiring, and the portal configuration steps that most installers miss.
STS handles GivEnergy battery additions end to end — compatibility check, supply and installation, CAN bus commissioning, portal configuration and DNO notification where required.
Get a battery expansion quote → Generic battery expansion guideThis page covers battery expansion for GivEnergy hybrid inverters and AIO systems — including model-specific expansion limits, battery generation compatibility, and GivEnergy portal configuration. If you have a Sunsynk, Growatt, SolaX or Fox ESS system, see the generic battery expansion guide instead.
GivBat Gen 3 expansion batteries
GivEnergy's current battery range uses LiFePO4 chemistry with 100% depth of discharge, IP65 weatherproofing, and a 12-year warranty with unlimited cycles. Two capacities are available for low-voltage hybrid systems.
All prices include battery hardware, installation by a GivEnergy approved installer, CAN bus commissioning, and portal configuration. DNO notification handling is available as an add-on where required.
GivEnergy inverter expansion limits
Every GivEnergy inverter model has a maximum battery capacity. Exceeding this causes BMS faults and may damage the inverter. Check your model before ordering.
| Inverter model | Max batteries | Max capacity | Compatible battery |
|---|---|---|---|
| Hybrid 3.6kW Gen 3 | Up to 5 | 47.5kWh | GivBat 5.12 or 9.5 Gen 3 |
| Hybrid 5.0kW Gen 3 | Up to 5 | 47.5kWh | GivBat 5.12 or 9.5 Gen 3 |
| Hybrid 8.0kW Gen 3 | Up to 5 (LV) or HV stack | 47.5kWh (LV) | GivBat Gen 3 (LV) or HV stackable |
| Hybrid 3.6/5.0kW Gen 2 | Up to 5 | Check datasheet | GivBat Gen 1, Gen 2 or Gen 3 (with correct cable) |
| Hybrid 3.6/5.0kW Gen 1 | Up to 4–5 | Check datasheet | GivBat Gen 1, Gen 2 or Gen 3 (with correct cable) |
| AIO 2 + MPPT | Up to 2 expansion units | 13.5kWh per expansion | GivEnergy AIO 2 expansion battery (307V HV) |
| AIO (original AC-coupled) | Limited | Model-dependent | Original GivBat units — match generation |
Check your serial number prefix — GivEnergy has released multiple hardware generations of the same nominal inverter model. The expansion limits above are typical but can vary by production batch. Always cross-reference against the technical datasheet for your specific inverter, accessible via the GivEnergy portal under Device > Technical Details.
Battery generation mixing — what works and what doesn't
GivEnergy has released three battery generations. All cross-generation battery combinations are supported with the right adapter cable and compatible firmware — but inverter compatibility varies. Here's the full picture.
Installed in the majority of UK GivEnergy systems up to approximately 2022. Models include the GivBat 2.6 (2.6kWh, 80% DoD), GivBat 5.2 (5.2kWh, 80% DoD) and GivBat 8.2 (8.2kWh, 100% DoD). Uses DIP switch Master/Slave and ring terminal connections.
Introduced in late 2022. Updated BMS with improved thermal management. The GivBat 9.5 Gen 2 (9.5kWh, 100% DoD, unlimited cycles) is the primary unit. Uses all-in-one plug connectors with integrated DC MCB.
Current production range. GivBat 5.12 Gen 3 (5.12kWh) and GivBat 9.5 Gen 3 (9.5kWh), both with 100% DoD and unlimited cycles. Lighter and more compact than earlier generations. Supports up to 5 in parallel.
| Battery combination | Supported? | Cable required | Notes |
|---|---|---|---|
| Gen 1 + Gen 2 on same string | Yes | Plug-to-lug cable | DC MCB required between batteries |
| Gen 2 + Gen 3 on same string | Yes | Plug-to-plug cable | Gen 3 must be master · DC isolator required |
| Gen 1 + Gen 3 on same string | Yes | Plug-to-lug cable | Gen 3 must be master · DC isolator required |
| Inverter generation | Gen 1 battery | Gen 2 battery | Gen 3 battery |
|---|---|---|---|
| Gen 1 inverter | ✓ Ring-to-ring | ✓ Lug-to-plug | ✓ Lug-to-plug |
| Gen 2 inverter | ✓ Lug-to-plug | ✓ Plug-to-plug | ✓ Lug-to-plug |
| Gen 3 inverter | ✓ Lug-to-plug | ✓ Plug-to-plug | ✓ Plug-to-plug |
When mixing battery generations, all units must be running compatible firmware versions. The Gen 3 battery must always be set as master (via DIP switches) and older generation batteries as slaves. A DC isolator is required between different generations to protect the slave batteries. Maximum five batteries total regardless of generation mix.
Gen 3 batteries work with Gen 1, Gen 2 and Gen 3 inverters using the appropriate cable type (lug-to-plug for Gen 1/2 inverters, plug-to-plug for Gen 3). Older batteries also work with newer inverters. The key requirement is that all batteries must be on compatible firmware versions. If you're unsure which generation you have, check the serial number on the inverter and battery labels or ask STS to verify before ordering.
How the installation works
A GivEnergy battery expansion must be carried out by a GivEnergy approved installer who is a qualified electrician. Self-installation voids the manufacturer warranty. This is what the process looks like from start to finish.
Before anything else, the installer confirms your inverter model, current battery generation, remaining expansion capacity, and whether a DNO modification notification will be required. STS carries out this check remotely — avoiding a wasted visit if the system is not expandable or if an incompatible battery has been ordered.
The system is shut down following GivEnergy's prescribed sequence: AC isolator off, DC solar isolator off, battery isolator off. All isolators are locked out before work begins. The existing battery SoC is noted so it can be verified post-installation. See the safe shutdown guide for the correct procedure.
The new battery unit is mounted — either stacked alongside the existing battery or in a separate location, depending on available wall space and cable runs. DC power cables are connected to the battery string. The GivBat 5.12 Gen 3 weighs 48kg and the 9.5 Gen 3 weighs 85kg — wall-mounting may require additional bracket support.
GivEnergy batteries communicate via a CAN bus daisy-chain using RJ45 connectors. The new battery is inserted into the chain between the previous last battery and the CAN bus terminator. The 120-ohm terminator plug moves to the new last battery in the chain. Missing or incorrect termination is the most common cause of post-expansion CAN communication faults.
With the system re-energised, the installer logs into givenergy.cloud, navigates to the inverter device settings, and updates the battery unit count and total system capacity. The charge schedule is also reviewed — overnight import windows are extended if needed to fill the larger battery stack. Without this step, the inverter's SoC readings will be incorrect.
A full charge and discharge cycle confirms that all batteries are detected, balanced, and behaving correctly. Battery cell voltages are checked across the string. The commissioning sheet is updated with the new system capacity, and the installer submits a DNO modification notification confirming the updated storage configuration.
GivEnergy portal configuration after battery addition
Portal configuration is the step most commonly skipped by third-party installers — and the one that causes the most ongoing problems. Here's exactly what needs changing.
If a previous installer added a battery without updating the portal settings, STS can correct this remotely. We access the portal, verify the battery count and capacity values, recalibrate the SoC if needed, and adjust the charge schedule. Book a remote session — most portal reconfiguration issues are resolved in under an hour.
DNO notification when adding a battery
Whether your system falls under G98 or G99 is determined by your inverter's output power — not by battery storage capacity. This is a common misconception.
If your inverter is rated at or below 3.68kW per phase — such as the GivEnergy Hybrid 3.6kW — it falls under G98. Your installer submits a notification to the DNO after installation. No prior approval is needed and there is no waiting period.
If your inverter exceeds 3.68kW per phase — such as the GivEnergy Hybrid 5.0kW or 8.0kW — it falls under G99. A variation application must be submitted to and approved by your DNO before system modifications are energised. G99 applications typically take 2–8 weeks.
The G98 and G99 engineering recommendations govern the connection of generating and storage equipment based on the inverter's rated output power per phase. Adding more battery storage does not change your G98/G99 classification — that was determined when the inverter was first installed. However, you should still notify your DNO of any material change to the system. See the G98 vs G99 guide for full details, or our DNO export application support service if you need help with the paperwork.
Updating your charge schedule for expanded capacity
Adding storage capacity changes how long your battery takes to charge overnight — and may require updates to your smart tariff settings to get the full benefit.
| Expansion added | Extra charge time (~3kW rate) | Octopus Intelligent / Flux | Manual Agile schedule |
|---|---|---|---|
| + 5.12kWh (1 × GivBat 5.12) | ~2 hrs additional | Review target SoC setting | Extend window by 2 hrs |
| + 9.5kWh (1 × GivBat 9.5) | ~3.5 hrs additional | May need earlier start time | Extend window by 3–4 hrs |
| + 10.24kWh (2 × GivBat 5.12) | ~4 hrs additional | Reconfigure smart charge target | Extend window to 4–5 hrs |
| + 19kWh (2 × GivBat 9.5) | ~7 hrs additional | Full Intelligent Go window needed | Consider second dispatch slot |
For users on Octopus Intelligent Go, the smart charging algorithm handles scheduling automatically once portal capacity is updated correctly. For manually scheduled tariffs (Agile, Flux, Go), review your charge window length and consider using the GivEnergy portal's AC charge schedule to set both a start time and a target SoC rather than just a fixed end time. See the Octopus Flux guide for tariff-specific configuration.
GivEnergy battery expansion — common questions
Gen 3 hybrid inverters (3.6kW, 5.0kW and 8.0kW) support up to five GivBat units in parallel using 51.2V low-voltage batteries. With five GivBat 9.5 Gen 3 units that gives a maximum of 47.5kWh. The 8.0kW Gen 3 also supports high-voltage stackable batteries for larger installations. The maximum is always five battery units regardless of capacity mix.
Yes — GivEnergy batteries can be mixed across all three generations using the correct adapter cables and compatible firmware. Gen 1 + Gen 2 use a plug-to-lug cable, Gen 2 + Gen 3 use a plug-to-plug cable, and Gen 1 + Gen 3 use a plug-to-lug cable. Gen 3 must always be the master battery when mixing. A DC isolator is required between different generations. Gen 3 batteries also work with all inverter generations (lug-to-plug for Gen 1/2 inverters). The maximum remains five battery units total.
No. The portal requires manual configuration — you must update both the battery count and total capacity values in the inverter's device settings at givenergy.cloud. If this step is skipped, the inverter will report incorrect SoC values and the battery will appear to be full long before it actually is. Your overnight charge schedule will also need reviewing.
You should notify your DNO of the system modification. Whether your system falls under G98 or G99 depends on your inverter's output power, not battery storage capacity. Inverters rated at or below 3.68kW per phase (such as the Hybrid 3.6kW) fall under G98 — notification only, no prior approval. Inverters above 3.68kW (such as the Hybrid 5.0kW and 8.0kW) require G99 — prior approval from the DNO before changes are energised.
The three most common causes are: the CAN bus 120-ohm terminator wasn't moved to the new last battery in the chain, an RJ45 connection is loose or incorrectly wired, or the battery generation is incompatible with the inverter. Check the CAN bus connections first, then verify generation compatibility. If connections are solid, STS can diagnose remotely via portal data.
Yes — your overnight charge window should be reviewed after any battery addition. If you're on Octopus Intelligent Go, the algorithm adapts once the portal capacity is updated. For Agile or Flux with a manual schedule, you'll need to extend the charge window to ensure the larger stack fills completely before the off-peak window closes. A 9.5kWh addition requires roughly 3–4 additional hours at typical overnight import rates.
Want to expand your GivEnergy storage?
STS handles GivEnergy battery additions from compatibility check through to commissioning — including battery supply, CAN bus setup, portal configuration, and DNO notification where required. Tell us your model and we'll confirm what's possible.