POWISER VOLIX 3 ULTRA 12K — 12kW Portable Backup, on Casters

Whole-home backup power that rolls where you need it: a 12kW split-phase system on casters, with true UPS switching, dual solar inputs and no permanent wall installation to commit to.

Why it works in a serious garage

• 12kW / 12,000VA split-phase, 18,000VA peak. Real 120/240V output means the whole shop — compressor, welder, Level 2 charger, well pump — not just the 120V circuits a portable unit covers.
• True UPS, not just backup. 10 ms transfer time, so computers, networking gear and diagnostic equipment ride through an outage without rebooting.
• Portable, with no install. On casters and plug-connected rather than hardwired into your panel. If you move, it moves. That is the whole argument for this over a wall-mounted system.
• Outlets that match real equipment. Three 20A 120V outlets, a 30A 120V outlet and a 30A 120V/240V outlet — so RV service, welders and 240V tools plug in directly, without an adapter or a subpanel.
• Dual solar inputs, high and low voltage. Two high-voltage MPPT channels take a roof array up to 10,000W, and a separate 1,300W low-voltage input at 12–60Vdc takes 12V or 24V panels directly — useful for a camper, trailer or existing 12V setup without a second controller.

Specifications

Overload protection is staged: above 102% of rated load the unit alarms and shuts output down after 5 minutes, above 110% after 10 seconds, and above 125% after 5 seconds.

Protection and control

• Short-circuit, over-voltage, under-voltage, overload and reverse-feed protection
• Segmented and scheduled charge and discharge, with an energy-saving mode that cuts no-load consumption
• Four charging modes — solar only, mains priority, solar priority and hybrid
• Three system configurations supported — CT metering, UPS-style backup panel, or an external automatic transfer switch

What’s in the box

• POWISER VOLIX 3 ULTRA 12K on integrated casters
• User manual

Shipping & delivery

At 140 kg (309 lb) this ships by freight on a pallet, not parcel. Confirm your delivery access before ordering. Expect curbside delivery on a liftgate truck — the carrier will not bring it into the garage. The casters make it manageable once it is on the ground and on a flat surface, but getting it off the truck and over a threshold is a two-person job. Inspect the crate before signing.

Class 9 hazardous goods, ground or LTL freight only, no air, curbside delivery, someone must be present, excluded from free shipping.

Frequently asked questions

Can it run 240V equipment?
Yes. Output is split-phase 120/240Vac and there is a dedicated 30A 120V/240V outlet on the unit, alongside a 30A 120V and three 20A 120V outlets. That is the main thing separating this from portable power stations, which are almost all 120V only.

Is it UL listed?
Not yet. The unit carries FCC SDoC; UL 9540 and UL 9540A certification is pending with POWISER. Until it is issued, treat this as an off-grid and plugged-loads unit rather than a grid-tied installation. If you intend to feed household circuits through a transfer switch or the HOME PANEL, wait for the certification and check what your local authority requires first. We will publish certificate numbers here as soon as POWISER supplies them.

Does it need an electrician?
Not in the way a hardwired system does — it is a portable unit on casters rather than something bonded into your service panel. If you want it feeding household circuits through a transfer switch or the matching HOME PANEL, that connection does need a licensed electrician and requirements vary by jurisdiction. Note it is IP20 rated: indoor use only, not a carport or an exposed wall.

How much solar can I connect?
Two high-voltage MPPT channels take up to 10,000W combined at 32A per channel, with a 500Vdc open-circuit ceiling. Separately, a 1,300W low-voltage input accepts 12–60Vdc panels directly. Confirm the high-voltage operating window with us before sizing strings — the manufacturer’s documentation is inconsistent on that figure and we will not guess at it.

How is this different from the H12 PRO?
Same 12kW split-phase output and the same 10 ms transfer. The H12 PRO mounts to a wall, hardwires into your panel and runs at 48Vdc. The ULTRA 12K rolls on casters at 51.2Vdc and plugs in. Choose the H12 PRO for a permanent whole-home install, the ULTRA if you want backup you can relocate — or take to a site, an RV or a second property. Their batteries are not interchangeable.

Can I add more later?
Up to six units run in parallel for 72kW. Three units paired with the VOLIX 3 HOME PANEL bring the system to 36kW of AC output across 12 circuits.

Build out the rest of the bay

• Autel AC Elite Home 50A 12kW EV Charger — the Level 2 charger this system is sized to support.
• ALLPOWERS SF-200 200W Flexible Solar Panel — low-profile panels for the high-voltage array input.