What size range counts as a C&I energy storage system?

Roughly 30kWh at the low end up to several MWh. The band most often bought from a factory is 100kWh to 500kWh, because that range fits standard rack cabinets and a single 20ft container without needing utility-scale interconnection studies.

Is a battery manufacturer the same as a system integrator?

No. A cell or pack manufacturer builds the battery. A system integrator assembles batteries, PCS, EMS, switchgear and fire suppression into a working system. A trading company sells someone else's product. Only the first two can answer deep technical questions without calling a supplier first.

Can I buy C&I storage directly from a Chinese factory?

Yes, and it is the normal route for importers and EPC contractors. You typically buy the battery racks and, depending on scope, the PCS and EMS. Confirm who provides commissioning and warranty service in your country before you sign, because that is where factory-direct deals most often break down.

C&I Energy Storage System Manufacturer: How to Source 100kWh to 1MWh

Type C&I energy storage manufacturer into a search box and you get three completely different companies quoting what looks like the same product. One makes the battery. One assembles a working system. One sells somebody else's box with a new logo on it. The quote differs by 30 to 40 percent between them, and so does what happens when something fails in year three. This page is about telling them apart before you send money.

The three suppliers behind the same quotation

A cell or pack manufacturer runs a production line: cells in, welded modules out, with grading, welding and burn-in under its own roof. An integrator buys those packs and adds the PCS, EMS, switchgear, enclosure and fire suppression, then commissions the whole thing. A trading company does neither and resells.

None of the three is automatically wrong for your project. A trading company with a real service partner can be fine for a single small cabinet. But the price band and the risk profile are not the same, and the only way to know which one answered your email is to ask questions they cannot delegate.

What a factory actually supplies at 100 to 500kWh

This is the band most buyers source, and it is worth being precise about scope, because the gap between battery only and full system is where budgets break.

Battery racks — 48V or 51.2V LiFePO4 modules, typically paralleled up to 16 units per group, each module carrying its own BMS with a master controller on top.
PCS (inverter) — sized to your peak demand window, not to your total site load. Often quoted separately, sometimes bundled.
EMS — the software that decides when to charge and discharge. Without it, peak shaving does not happen.
Fire suppression and environment — detection plus aerosol or gas suppression, and for container systems, thermal management.
Balance of system — cables, busbars, breakers, earthing. Frequently forgotten in factory quotes.

A battery-only quote at 100kWh and a turnkey quote at 100kWh can differ by half. Always compare on the same scope line. If you want the engineering detail of what physically arrives, see what ships in a 100kWh to 1MWh C&I system.

Five questions that settle which one you are talking to

These are ordered by how hard they are to fake. A trading company can answer the first two; the last three usually end the conversation.

Which cells, from which batch? A manufacturer names the cell model and can produce the grading report for the batch your packs came from. Everyone else says Grade A and stops there.
What is the parallel limit, and on what protocol? Real answer: a number of units, plus CAN or RS485 and which central inverters it has been paired with. Vague answer: it depends on your system.
Can you show burn-in records for my units? Manufacturers run full charge-discharge cycles before shipping and can show it. Nobody else can.
Does the certificate name this exact model? Certificates are issued per model. A certificate for a similar product fails inspection. See how to read a battery test report.
Who commissions it in my country? The honest answer may be your local partner, which is fine — but it has to be said before the sale, not discovered after.

Where each capacity tier changes the conversation

100 to 300kWh — usually rack cabinets in an existing plant room. No civil work, shortest lead time, easiest to expand later. This is where most first-time buyers should start.

300 to 500kWh — still rack-based for many designs, but you are now into serious switchgear, a dedicated room or outdoor enclosure, and utility notification in most markets.

500kWh to 1MWh — container territory. Civil work, interconnection studies, fire authority review, and a project timeline measured in months rather than weeks. At this size the questions above stop being optional.

For the economics at each size, our C&I energy storage buyer's guide covers cost per kWh, payback drivers and sizing examples.

OEM and ODM: what customization is realistic

Manufacturers can realistically change enclosure colour and branding, labelling and documentation language, BMS parameter sets, rack height and interface layout, and packaging. They usually cannot change cell chemistry or cell format without a volume commitment, redesign the BMS firmware from scratch for a small order, or certify a one-off variant — certification costs are fixed regardless of order size, which is why small custom certifications rarely make sense.

Lead time and shipping, honestly

Production for a standard 100 to 500kWh rack order typically runs a few weeks once the cell batch is allocated. Container-scale systems run longer. Sea freight dominates: UN38.3 test summary and Class 9 dangerous-goods documentation are mandatory, and a missing or mismatched UN38.3 is the single most common reason a shipment is held at port. Details in our battery shipping and DDP guide.

Frequently asked questions

Do I need a manufacturer or an integrator?

If you have an EPC or electrical contractor who can handle PCS, switchgear and commissioning, buy battery racks from a manufacturer and save the integration margin. If you want one throat to choke, buy the integrated system and pay for it.

Why do quotes for the same 200kWh differ so much?

Usually scope, not greed. One is battery-only, one includes PCS and EMS, one includes installation and commissioning. Put them on the same scope line before comparing. Cell grade accounts for most of the remaining spread.

What is the minimum order for factory-direct C&I?

There is no universal MOQ. Standard rack configurations often ship from a single cabinet; deep customization needs volume. The practical constraint is certification and tooling, not willingness to sell.

Sourcing a C&I system?

Send your peak demand kW, target kWh and destination port. We will confirm what we build in-house, what we integrate, and what we do not do — before you commit.

Request a Quote →