EcoFlow Extra Battery Expansion Adapter for DELTA 3 MAX | Ultra Plus
Overview
The EcoFlow Extra Battery Expansion Adapter is the cable you need to connect a second Smart Extra Battery to the EcoFlow DELTA 3 Max Plus or EcoFlow DELTA 3 Ultra Plus. These power stations only have one extra battery output port, so this adapter splits the connection and lets you stack two compatible Smart Extra Batteries through a single cable to unlock the full expandable capacity (up to 10kWh on DELTA 3 Max Plus, up to 12kWh on DELTA 3 Ultra Plus).
You don't need this adapter for your first extra battery, only when you want to add a second. Compatible Smart Extra Batteries are the EcoFlow DELTA 3 Max Plus Smart Extra Battery (2048Wh) and the EcoFlow DELTA Pro 3 Smart Extra Battery (4096Wh). For best results, we recommend using two of the same battery type on the adapter.
Key Features:
- Function: Connects two Smart Extra Batteries to a single Extra Battery Port on the host power station
- Compatible Power Stations: DELTA 3 Max Plus, DELTA 3 Ultra Plus
- Compatible Extra Batteries: EcoFlow DELTA 3 Max Plus Smart Extra Battery (2048Wh), EcoFlow DELTA Pro 3 Smart Extra Battery (4096Wh)
- Connection: Single cable to the power station, splits into two outputs for the extra batteries
- Power Required Per Side: No external power needed, draws through the host power station
What's in the Box?
- 1 x EcoFlow Extra Battery Expansion Adapter cable
- 1 x User Documentation
- Warranty: 1-year warranty
Note: Extra batteries and host power stations are not included. This is a cable/adapter accessory only. You need the host power station and two compatible Smart Extra Batteries (sold separately) to use this adapter.
Why You Need This Adapter
The DELTA 3 Max Plus and DELTA 3 Ultra Plus each have one Extra Battery Port on the back. With the standard battery cable that ships with each Smart Extra Battery, you can only connect one extra battery at a time. To unlock the full expandable capacity rating for each power station, you need to connect two extra batteries, and this adapter is the only EcoFlow-approved way to do it.
Plug the single-end side of the adapter into the host power station's Extra Battery Port, then plug each of the two split ends into a compatible Smart Extra Battery. The power station automatically detects and balances both batteries through one connection.
Maximum Expandable Capacity Unlocked
The DELTA 3 Max Plus has a standalone capacity of 2048Wh. Add two Smart Extra Batteries via this adapter and the total system capacity expands up to 10kWh, enough for multi-day off-grid trips, extended power outages, or heavy daily loads. The DELTA 3 Ultra Plus starts at 3072Wh and expands up to 11kWh with two extra batteries.
Pairs Well With
This adapter is essential for anyone running a two-battery setup on the EcoFlow DELTA 3 Max Plus or EcoFlow DELTA 3 Ultra Plus. Compatible batteries include the EcoFlow DELTA 3 Max Plus Smart Extra Battery (2048Wh) and the EcoFlow DELTA Pro 3 Smart Extra Battery (4096Wh).
Frequently Asked Questions
Do I need this adapter to use one extra battery?
No. One Smart Extra Battery connects to your DELTA 3 Max Plus or DELTA 3 Ultra Plus with the standard cable that ships with the battery. You only need the Expansion Adapter when you want to connect a second extra battery to reach the maximum expandable capacity.
Which power stations work with this adapter?
The Extra Battery Expansion Adapter is designed for the EcoFlow DELTA 3 Max Plus and EcoFlow DELTA 3 Ultra Plus only. It is not compatible with the DELTA Pro 3, DELTA Pro, DELTA 2, RIVER series, or any other EcoFlow power stations.
Should I use two of the same battery type on this adapter?
For best results, yes. We recommend running two of the same Smart Extra Battery model (either two DELTA 3 Max Plus or two DELTA Pro 3) on the adapter to ensure even charge and discharge across both batteries. If you want to combine different battery models, contact EcoFlow support or get in touch with us first to confirm your setup will work.
What warranty does the Extra Battery Expansion Adapter have in NZ?
The EcoFlow Extra Battery Expansion Adapter includes a 1-year warranty in New Zealand.