Expansion battery entity · 3.99 kWh LiFePO4 expansion · Current
Goal Zero Tank PRO 4000 Expansion Battery
3,994 Wh LiFePO4 expansion battery for the Goal Zero Yeti PRO 4000, 36.4 kg, the largest capacity in this family. Charges only through its host and has no user outlets. Up to four stack per Yeti PRO 4000, with a stated tipping-hazard warning. 5-year warranty.
Machine summary · expansion_battery · goal-zero-tank-pro-4000
- brand
- Goal Zero
- model_name
- Tank PRO 4000
- release_status
- current
- chemistry
- lifepo4
- capacity_wh
- 3994
- compatible_host_models
- Goal Zero Yeti PRO 4000
- has_own_outlets
- false
- weight_kg
- 36.4
- confidence_level
- high
- source_last_checked
- 2026-08-15
- json_export
- /expansion-batteries/goal-zero-tank-pro-4000.json
Overview
The Goal Zero Tank PRO 4000 is a 3,994 Wh LiFePO4 expansion battery (78 Ah at 51.2 V nominal) in a 36.4 kg case, the largest single expansion unit indexed here. It exists to enlarge the Goal Zero Yeti PRO 4000: Goal Zero states it works with the Yeti PRO 4000, and the manual states it must be used with a Yeti PRO 4000. It has no user outlets, only an accessory port, and charges solely through the host. Up to four units stack on one Yeti PRO 4000, and Goal Zero prints a tipping-hazard warning about tall stacks. Its cycle-life note is the most detailed of this family: 4,000 cycles to 80 percent of original capacity at 25 C with a 0.5C charge and discharge. Because that is a capacity-retention figure rather than a depth-of-discharge basis, no DoD-qualified cycle count is stored. Do not confuse it with the legacy Yeti Tank Expansion Battery V3, a lead-acid AGM unit that needs a separate Yeti Link module and never enumerates its hosts. Warranty is 5 years.
Variant note: Tank PRO 4000 (SKU 23110), the LiFePO4 expansion battery for the Yeti PRO 4000. Distinct from the legacy lead-acid Yeti Tank Expansion Battery V3.
Data note: Values traced to the Goal Zero Tank PRO 4000 product page and its user guide PDF (2026-08-15), SKU 23110. capacityWh is this unit's own 3,994 Wh (78 Ah x 51.2 V nominal). cycleLifeCycles is null by policy: Goal Zero's 4,000-cycle claim is quoted to 80% capacity retention (with a stated 25 C, 0.5C basis), which is not a depth-of-discharge basis; the count is kept in cycleLifeConditionsNote. hasOwnOutlets is false: only an accessory port, no user outlets, and it charges only through the host. Do NOT index the legacy Yeti Tank Expansion Battery V3: it is lead-acid AGM, sold out, requires a separate Yeti Link module, and never enumerates its hosts (unshippable compatibility).
Specifications
Host compatibility leads this table because it is what makes an expansion battery meaningful, and it is recorded verbatim from the manufacturer and never inferred. The capacity shown is this unit's own rated energy, not a combined host-plus-expansion system total. Any cycle-life figure carries the depth of discharge it is quoted at, and figures the manufacturer does not publish are left blank rather than estimated. Exact claims and links are in the provenance table.
| Attribute | Value |
|---|---|
| Official compatibility statement | Works with the Yeti PRO 4000 |
| Host models named by the manufacturer | Goal Zero Yeti PRO 4000 |
| Expansion units the host supports | Up to 4 |
| Attribute | Value |
|---|---|
| Rated energy | 3,994 Wh |
| Rated capacity | 78 Ah |
| Nominal voltage | 51.2 V |
| Chemistry | LiFePO4 (lithium iron phosphate) |
| Attribute | Value |
|---|---|
| Outlets on the expansion unit itself | None. It adds capacity to the host and has no output ports of its own |
| Direct charging inputs | None direct: the Tank PRO 4000 has an accessory port only and charges solely through the host Yeti PRO 4000. |
| Attribute | Value |
|---|---|
| Rated cycle life | No cycle-life figure published |
| Cycle-life test conditions | Goal Zero states 4000 cycles to 80% of original capacity at 25 C with a 0.5C charge and discharge. That is a capacity-retention figure, not a depth-of-discharge basis, so no DoD-qualified cycle count is stored. |
| Attribute | Value |
|---|---|
| Charge temperature range | 0 °C to 52 °C (32 °F to 126 °F) |
| Discharge temperature range | -20 °C to 60 °C (-4 °F to 140 °F) |
| Attribute | Value |
|---|---|
| Weight | 36.4 kg (80.2 lb) |
| Dimensions (L × W × H) | 543 × 351 × 233 mm |
| Attribute | Value |
|---|---|
| Warranty | 5 years |
| Release status | Current |
| Market region | US |
Use cases
- Enlarging a Goal Zero Yeti PRO 4000 for multi-day home backup or off-grid use
- Systems that stack several batteries for large stored energy behind one Yeti PRO 4000 inverter
Strengths and weaknesses
Strengths
- Largest expansion capacity here at 3,994 Wh in a single unit
- The richest published cycle-life conditions in this family (temperature and 0.5C charge/discharge stated)
- 5-year warranty, the longest here alongside the EcoFlow and Anker units
- Chemistry, capacity, weight and dimensions all published with a full user guide PDF
Weaknesses
- No user outlets and no direct charging: it charges only through the Yeti PRO 4000
- Bound to a single host, the Yeti PRO 4000
- 36.4 kg: the heaviest unit here, and stacks carry a stated tipping hazard
- Easy to confuse with the legacy lead-acid Yeti Tank Expansion Battery V3, which is a different product
Where to buy
| Merchant | Price | Checked | Availability | Link |
|---|---|---|---|---|
| Goal ZeroprimaryManufacturer direct | Not tracked | — | — | View at Goal Zero |
Sources and provenance
Core specifications come from official manufacturer sources only, with the exact claim text preserved per field. Spec sheets and manuals outrank marketing copy. See the methodology for the full policy.
| Field | Normalized value | Raw claim | Source | Confidence |
|---|---|---|---|---|
chemistry | lifepo4 | LiFePO4 | Official product page | high |
capacityWh | 3994 | 3994Wh | Official product page — This unit's own energy (78 Ah x 51.2 V = 3993.6 Wh). NOT a combined-system total. | high |
capacityAh | 78 | 78Ah | Official manual (PDF) | high |
nominalVoltageV | 51.2 | 51.2V | Official manual (PDF) — 78 Ah x 51.2 V = 3993.6 Wh, matching the stated 3994 Wh within rounding. | high |
weightKg | 36.4 | — | Official manual (PDF) — Published weight 36.4 kg; sourced via research handoff (2026-08-15). | high |
dimensionsMm | [543,351,233] | — | Official manual (PDF) — 543 x 351 x 233 mm; sourced via research handoff (2026-08-15). | high |
officialCompatibilityStatement | Works with the Yeti PRO 4000 | Works with the Yeti PRO 4000 | Official product page — The manual states it must be used with a Yeti PRO 4000. | high |
compatibleHostModels | ["Goal Zero Yeti PRO 4000"] | must be used with a Yeti PRO 4000 | Official manual (PDF) — Single named host. Up to four units per host, with a tipping-hazard warning. | high |
cycleLifeConditionsNote | 4000 cycles to 80% of original capacity at 25 C with a 0.5C charge and discharge | 4000 cycles to 80% of original capacity at 25 C with a 0.5C charge and discharge | Official manual (PDF) — Capacity retention, not DoD, so cycleLifeCycles is left null. | high |
warrantyYears | 5 | — | Official product page — 5-year warranty; sourced via research handoff (2026-08-15). | high |
chargeTempRangeC | [0,52] | — | Official manual (PDF) — Charge 0 to 52 C, discharge -20 to 60 C; sourced via research handoff (2026-08-15). | high |