Tesla Powerwall 3 Expansion 13.5kWh DC Battery Expansion Only - 1807000-20-B
Tesla Powerwall 3 Expansion 13.5kWh DC Battery Expansion Only - 1807000-20-B
Tesla Powerwall 3 Expansion 13.5kWh DC Battery Expansion Only - 1807000-20-B
Tesla Powerwall 3 — 13.5 kWh fully usable, 11.04 kW of AC output and a 20 kW solar inverter in one unit.
A battery pays for itself by moving energy in time: solar generated at midday and electricity bought on an overnight rate, both spent in the evening. What decides whether it pays is the usable capacity, the charge rate and the cycle life.
Please read before ordering
About the Tesla Powerwall 3
Powerwall 3 folds the solar inverter into the battery. One unit takes up to 20 kW of array across three MPP trackers, stores 13.5 kWh of fully usable energy and puts out up to 11.04 kW of AC — enough to start a load rated at 185 A locked-rotor, which is the specification that decides whether a heat pump or a well pump will restart on backup.
Capacity and power scale separately. Up to four Powerwall 3 units give more power; up to three Expansion units behind one give more energy, to a maximum of seven units in total.
Solar to home is 97.5 % efficient and solar to battery to home 89 %. The enclosure is IP55 with IP67 around the battery and power electronics, rated indoor and outdoor from −20 to +50 °C.
Which inverter will run this battery?
This is the Powerwall 3 platform: an all-in-one unit holding the solar inverter, the 13.5 kWh battery and the backup supply, with inverter-less DC Expansion batteries behind it.
There is no separate inverter to choose. A Powerwall 3 contains its own three-MPPT solar inverter and takes up to 20 kW of array. An Expansion is the other way round — a battery with no inverter, which works only behind a Powerwall 3, up to three of them, floor mounted, joined by an Expansion harness.
Stack rules, cabling and what else the job needs
The details that decide whether this battery suits the system:
- Nominal AC output is configurable from 3.68 kW to 11.04 kW at 230 V, with maximum continuous current from 16 A to 48 A and an overcurrent protection device from 20 A to 63 A to match.
- Maximum continuous charge power is 5 kW DC, or 8 kW DC with Expansion units fitted; the AC figure is configurable to the same limits.
- Solar: 20 kW STC maximum, 600 V withstand, 60 – 550 V input range, 60 – 480 V MPPT range, three MPP trackers at 30 A and 38 A Isc each.
- Load start capability 185 A LRA. Maximum output fault current 160 A for one second, short-circuit rating 10 kA.
- Up to four Powerwall 3 units for power and up to three Expansion units for energy, seven units maximum. Islanding uses Backup Gateway 2.
- Expansion units are 52 – 92 Vdc, connect in parallel, are not field serviceable, and are floor mount only when stacked behind a Powerwall 3. The Expansion harness comes in 0.5 m, 2 m and 4 m.
- Powerwall 3 is 1,105 × 609 × 193 mm and 130 kg; an Expansion is 1,105 × 609 × 168 mm and 118.5 kg with its glass front cover and bracket.
- The unit must be reliably connected to the internet to secure the full ten-year warranty. Cellular should not be the primary connection.
- Certified to G98 and G99, IEC 62109-1/-2, IEC 62477-1, IEC 62933-5-2, IEC 62619:2022, UL 9540A and UN 38.3.
Where this battery earns its place
The Powerwall 3 is specified most often for these jobs.
Things worth knowing about this listing
- The Expansion is a DC battery with no inverter in it and works only behind a Powerwall 3 — up to three of them, floor mounted, joined by an Expansion harness. It is not a standalone battery and is not field serviceable.
- Up to four Powerwall 3 units for power and up to three Expansion units for energy, seven units in total.
Tesla Powerwall 3 Expansion technical data
Questions we get asked about this inverter
Do I need a separate inverter?
No. Powerwall 3 contains a three-MPPT solar inverter and takes up to 20 kW of array.
What is the Expansion?
A 13.5 kWh DC battery with no inverter in it. It only works behind a Powerwall 3 — up to three of them, floor mounted, joined by an Expansion harness.
How much of the 13.5 kWh can I use?
All of it. Tesla quote 13.5 kWh usable AC energy.
How many units can I have?
Up to four Powerwall 3 units for power and up to three Expansions for energy, seven in total.
Does it need an internet connection?
Yes, to secure the full ten-year warranty. Tesla say cellular should not be the primary connection.
Documents, advice and trade pricing
Every datasheet, certificate, installation manual and warranty document we hold for this product is in the Documents tab below. See the rest of our battery range, our hybrid inverters and our solar panels, or email sales@clearraysolar.com if you would like us to check a battery and inverter pairing before you order.
Usable energy is the nominal capacity multiplied by the depth of discharge, and both figures are in the Technical Specifications. Most current lithium batteries allow 90% or more.
It needs to appear on your inverter manufacturer's approved battery list and the voltage ranges have to match. Send us your inverter model and we'll confirm compatibility before you order.
Most systems stack in modules up to a maximum number of units per installation, given in the datasheet. Keep to the same model, and buy the full stack together where budget allows.
Only where the IP rating and operating temperature range allow it - both are in the Technical Specifications. Cold reduces usable capacity, so a garage or utility space is usually the better location.
Yes, where the inverter supports timed or forced charging. Paired with a time-of-use tariff this is often the quickest route to a shorter payback.
Warranty terms, and the throughput or cycle count they are based on, are listed under the Warranty tab and in the manufacturer documentation.
Build your complete solar system
Everything you need in one place.
- Inverters
- Batteries
- Mounting Systems
- Cabling & Accessories
- Protection Devices
Delivery times vary by region:
- UK — 1-2 business days
- Highlands & Islands — 1-2 business days
Returns accepted within 14 days of delivery for unused items in original packaging.
