SolaX Triple Power 5.8kWh Review UK: Specs, Price & Stacking

SolaX Power is one of the UK's most-installed hybrid inverter brands, and the Triple Power T-BAT H 5.8 V3 is its current high-voltage battery module — the piece that turns an X1 or X3-Hybrid G4 inverter into a full storage system. Unlike a third-party module such as the Pylontech US5000, which pairs with dozens of inverter brands, the Triple Power range is SolaX-only. This review works through SolaX's own datasheet and warranty terms, flags a stacking-capacity figure worth double-checking before you order, and compares it with the other batteries already covered on this site.

SolaX Triple Power 5.8kWh: specs and capacity

The T-BAT H 5.8 V3 is a 5.8kWh nominal, high-voltage LiFePO4 battery, with 5.5kWh usable at a 95% depth of discharge, per SolaX's own datasheet. As the “master” unit it houses the BMS; SolaX's HV11550 V3 “slave” modules of the same 5.8kWh capacity can be added to extend the string.

• Capacity: 5.8kWh nominal / 5.5kWh usable per module (95% DoD, tested at 0.2C charge/discharge at 25°C)
• Chemistry: LiFePO4 (LFP), with SolaX's flexible two-level battery heating for cold-weather charging
• Dimensions / weight: 474 x 715 x 150mm; 61.5kg for the master module (BMS + pack), 59.5kg for a slave module
• Power: 2.9kW rated charge/discharge per module, 4kW max; 25A recommended current, 35A max
• Cycle life: rated above 6,000 cycles at 95% DoD (test conditions: 25°C, 0.5C charge/discharge, to 70% end-of-life)
• Protection rating: IP66 — rated for indoor or outdoor installation, wall- or floor-mounted
• Communication: CAN 2.0 + RS485, plus an aerosol fire-suppression system built into the module
• Operating range: 0–55°C charging with heating off (down to -30°C with the heater active); -20–55°C discharging

The IP66 rating is a genuine advantage over an indoor-only module like the Pylontech US5000 (IP20) — it's one of the few high-voltage batteries in this bracket you can site outdoors or in an unheated garage without a second thought. Weight is worth flagging too: this site's own product listing states 52kg, which undersells it — SolaX's datasheet puts the master module at 61.5kg, so plan your mounting wall or floor bracket accordingly.

How far the Triple Power actually stacks

SolaX's own datasheet lists a maximum of six T-BAT H 5.8 V3 modules in a single cluster — 34.6kWh, not 23kWh. Some retailer listings (including, previously, our own) understate this at 23kWh, which is only a four-module stack. Six modules is the real single-cluster ceiling, and SolaX's datasheet notes that inverters with two battery ports can run two clusters in parallel for up to 69.1kWh total. Whichever figure you're quoted, cross-check it against the datasheet rather than a retailer's product page — ours included, until this correction.

The other number worth separating out is depth of discharge. SolaX's datasheet quotes the 5.5kWh usable-energy figure at 95% DoD, but the UK/Ireland performance warranty (below) only guarantees capacity retention up to a maximum specified DoD of 90% — a shallower, more conservative cycling regime than the headline usable-energy figure implies. That's not unusual for the industry, but it's worth knowing which number applies to which promise.

SolaX Triple Power 5.8kWh price and warranty in the UK

This site's own product catalogue lists the T-BAT H 5.8 V3 master module at £1,286.48 ex VAT. That's for the battery alone — a compatible X1 or X3-Hybrid G4 inverter, mounting and installer labour are priced separately, in the same way as a Pylontech-based system. Our home battery installation guide breaks down typical installed costs for hybrid-inverter-plus-battery setups.

SolaX's UK & Ireland warranty terms (V1.5, effective from products installed on or after 21 August 2024) give the T-BAT-SYS-HV-5.8 battery series a 10-year standard warranty, starting from the earlier of the installation date or nine months after the production date — provided the system is registered on SolaX Cloud within 90 days of commissioning; miss that window and the warranty simply defaults to counting from nine months after production instead. Separately, SolaX's performance warranty guarantees the battery retains at least 70% of its nominal energy for 120 months, or until it reaches 17.9MWh of cumulative energy throughput, whichever comes first — whichever limit is hit first ends the guarantee. The warranty is voided by conditions like moving the battery to a new address without a re-inspection, unauthorised third-party charge/discharge control software, or damage from flood, fire or lightning — standard exclusions, but worth reading in full before you sign off an install.

The catch: SolaX-only, and it needs a compatible inverter first

The Triple Power range only works with SolaX's own X1-Hybrid G4 and X3-Hybrid G4 high-voltage inverters — there's no cross-brand compatibility the way a Pylontech or Fox ESS module offers. That's the trade-off for the tighter BMS integration and the single-vendor warranty conversation: if your installer isn't already speaking SolaX, or you might want to switch inverter brands later, you're locked into their ecosystem for as long as this battery is on the wall. It also means checking your installer's specific G4 inverter model against SolaX's own battery-selection guidance before ordering, rather than assuming any hybrid inverter will pair with it. Our hybrid inverter buyer guide covers how to weigh a single-vendor stack like this one against a third-party battery kept deliberately inverter-agnostic.

SolaX Triple Power vs Pylontech US5000

The comparison that matters most for most UK buyers is high-voltage vs low-voltage third-party. The Pylontech US5000 is a 48V module that works across dozens of hybrid inverter brands, including SolaX's own lower-end range, and is typically cheaper per kWh once you're not paying for high-voltage architecture — but it's IP20, indoor-only, and needs a separate inverter conversation regardless of brand. The Triple Power's high-voltage design gives a modest efficiency edge on larger systems and comes IP66-rated for outdoor mounting, at the cost of being tied to SolaX's own inverter range for the life of the battery.

Who the SolaX Triple Power 5.8kWh suits

This is the right pick if your installer is already specifying, or you already own, a SolaX X1 or X3-Hybrid G4 inverter, and you want an outdoor-rated, wall- or floor-mountable battery with a straightforward single-vendor 10-year warranty. It's a weaker fit if you want to keep your options open on inverter brand, or if a lower cost-per-kWh third-party module like the US5000 matters more than the IP66 rating. Our battery sizing guide covers how a 5.8–34.6kWh stack like this one compares against other formats when you're working out how much capacity your home actually needs.