Find the family.
Then the exact fit.

10 kW–100 MW+; typically 2–12+ hour duration; power and energy separately scalable

50–500 kWh typical rack/cabinet; 400–1,500 Vdc; indoor/outdoor variants

2–30 kWh common stationary module; about 48–1,500 V systems assembled from modules

0.5 kVA–5 MW system range; single phase below about 20 kVA, three phase above; scalable parallel systems

0.5 kVA–5 MW; VFI topology; tower, rack, modular and central systems

10 kW–5 MW system; module sizes commonly 10–250 kW; N+1/N+X

200 kVA–5 MVA per unit; flywheel/diesel rotary and motor-generator variants

1 kVA–5 MW; transformerless or transformer-based; single/three phase

5 kVA–6 MVA+; LV and MV systems; harsh-environment and DC plant variants

10 kW–5 MW per system; parallel plants tens of MW; lithium, VRLA and flywheel options

24/48/110/125/220 Vdc; about 1–1,000 kW; telecom, substation and industrial variants

100 kW–2 MW per unit; typically 10–60 seconds ride-through; parallel systems

5–1,000 kWh per cabinet/string group; VRLA, lithium-ion and Ni-Cd; matching DC bus required

1 kW–5 MW; 24–1,500 Vdc; 1/3 phase AC input; modular hot-swap variants

1 kVA–5 MW; 24–1,500 Vdc input; 120–690 Vac output; standalone or UPS module

16–6,300 A; 120–690 Vac; 1/3 phase; maintenance/automatic transfer configurations

16–6,300 A; wall, cabinet or switchboard integrated; make-before-break options

50 V–15 kV test voltage; MΩ to multi-TΩ measurement; handheld, battery and mains-powered

2 V cells through 1,500 V systems; conductance/impedance/capacity/load testing; handheld to automated discharge banks

1 kVA–5 MW systems; battery age usually excludes batteries from valuation; modular parts often available

1 kVA through multi-MW systems; battery, bypass, load-bank, parallel and failover tests

24/48/110/125/220 Vdc; 20–5,000 Ah; lead-acid, Ni-Cd or lithium; 1–24+ hour autonomy

10–1,000 A; 24–220 Vdc; single/three phase; redundant/hot-swap and battery monitoring

50–400 kW output common; 100 kWh–2 MWh buffer; weak-grid and mobile variants