· SH Energy editorial
Most buyers compare capacity and price, then discover the paperwork or the after-sales path does not hold. The eight checks below are the ones that separate a supplier from a reseller who forwards emails.
1. Start with the model code, not the family name
A brochure that says “5–16 kWh” tells you nothing you can verify. Ask for the exact model codes you would write on a purchase order, then ask which of them are in production this quarter and which are being discontinued.
If the answer is a family name with no codes, you cannot check certificates, spare parts or compatibility later. That is not a paperwork problem; it is a product-control problem.
2. The four documents that decide a South African installation
For a grid-tied residential system, the paperwork usually comes down to four items. Ask for each one by name, for the exact model:
- NRS 097-2-1 — commonly required for grid-tied inverters. The municipality or the distributor decides whether your exact model is accepted.
- SSEG registration — the application, approval and meter change sit with the local municipality. The supplier's job is to give you the model documents the application needs.
- Certificate of Compliance (CoC) — issued by a registered electrician after installation. No supplier can issue it on your behalf.
- UN 38.3 and MSDS — needed before a carrier will accept the battery shipment, whether sea or air.
A supplier who can list which of these exist for the model, and which do not, is telling you something useful. One who says “all certifications available” without naming them is not.
3. Ask what happens after the first failure
The warranty conversation is where cheap supply becomes expensive. Ask three questions in writing:
- What is covered, and for how long, by model?
- Who performs the repair or replacement — the factory, a local partner, or you?
- Which parts are field-replaceable, and what is the lead time on them?
If every answer ends with “send it back to China”, the real cost is the weeks without a working system, not the freight.
4. Test the quote, not the catalogue
A complete quotation for a South African buyer should contain: the exact model, the inverter pairing, the Incoterm, the validity period, the document list, and the packing data. If any of those are missing, the price is not comparable to another quote that includes them.
Ask for the quote in writing with the document list attached. A verbal price with “documents to follow” is not a quotation; it is an opening position.
5. Red flags worth walking away from
- A certificate that does not name the model you are buying.
- A warranty promised in chat but absent from the quotation.
- A price that changes when you ask for the document list.
- A technical question answered only by forwarding your email to someone else.
- No answer on spare parts, or an answer that starts with “usually”.
6. The 30-minute qualification call
Before you place a sample order, run one call with these five questions. The answers tell you more than a catalogue:
- Which exact models do you hold IEC 62619 for, and who is the certificate holder?
- What is your RMA process, and where does a failed unit go?
- What is the lead time split between production, testing and booking?
- Can you send the protocol document for this battery and inverter pair?
- What do you do when a document is missing — say so, or substitute?
7. Compare the delivered scope, not the unit price
Two quotes for “10 kWh” can differ by the inverter rating, the cell batch, the certification scope, the packing and the Incoterm. Normalise before comparing: same model, same documents, same Incoterm, same warranty terms. Only then is the number meaningful.
8. Start with a sample, then a mixed container
A sample verifies the product and the documents. A mixed container verifies whether the supplier can plan and pack several models together — which is what a distributor actually needs. If you intend to sell a range, the mixed container is the more useful test.
Copy-ready supplier questionnaire
Where this fits
Market-specific document requirements for South Africa are on the South Africa sourcing page. The model-by-model document status is on the documents centre. If you are building a dealer line, the partner programme explains how the first order is structured.
Is a cheaper battery with the same kWh worth considering?
Only after the documents and the after-sales path are comparable. A lower price per kWh often reflects a smaller inverter, a different cell batch, thinner documentation or no local spare-parts path. Compare the whole delivered scope, not the headline capacity.
Do I need NRS 097-2-1 for an off-grid system?
Not necessarily. NRS 097-2-1 applies to grid-tied connection. An off-grid system that never exports may not need it, but the municipality and your registered electrician decide what applies to the site. Confirm before you specify, not after.
How long should a supplier take to answer a technical question?
A working day is a reasonable expectation for a model-specific question. If the answer is always forwarded to a factory without interpretation, you are dealing with a broker, not a supplier with technical capacity.
What if the supplier cannot provide a certificate for the exact model?
Then you do not have evidence for that model, regardless of what the family page says. Ask for the gap in writing and decide whether the project can proceed without it. A supplier who states the gap is more useful than one who implies coverage.
Discuss a South Africa sourcing enquiry
Send the models, the destination city and the documents your installer or municipality requires to jimmy@sunhongenergy.com, or message the desk on WhatsApp.
Scope
This guide describes supplier-qualification practice. Approval, registration and sign-off decisions remain with the municipality, the distributor and the registered electrician for the specific site.