· SH Energy editorial
The kWh line is the only line both quotes share. Usable energy, inverter power and phase, cell batch and BMS, the certification actually held for that model, the Incoterm and the payment terms all move the number before anyone adds a margin. Compare those six, then compare price.
1. What actually drives the number
In this market a quote arrives as one figure, usually per unit or per installed system. That figure is the sum of six decisions, and each one is checkable in writing. When two quotes differ, at least one of these is different — usually more than one.
- Usable energy — the capacity you can actually cycle, not the nameplate on the box.
- Inverter power and phase — a unit sized for a single-phase essential-loads panel is a different product from one built for a three-phase site.
- Cell batch and BMS — the same nominal capacity built from a different cell batch, with a different BMS and protection set, is a different cost base.
- Certification actually held for that model — evidence is held per model, not per family.
- Incoterm and landed cost — who pays freight, insurance, port charges and clearing, and where the risk transfers.
- Payment terms — deposit size, balance timing and what happens if the shipment slips.
If a supplier cannot answer these six in writing, the price is not yet comparable to anything.
2. Price per kWh: usable versus nameplate
The instinct is to divide the price by the kWh on the datasheet. That number is only useful if both quotes use the same definition, and they usually do not.
Three definitions get mixed together in conversation:
- Nameplate (nominal) capacity — what the pack is built from.
- Usable capacity — what the system will actually deliver between its upper and lower limits.
- Delivered energy per cycle — usable capacity after round-trip losses and the reserve the system keeps for its own protection.
Depth of discharge sits between the second and third. A pack cycled shallowly lasts longer and delivers less per cycle; a pack cycled deeply delivers more per cycle and ages faster. Neither is wrong — but the two produce different "per kWh" figures from identical hardware. Ask which definition the quote is using before you divide anything.
3. Where certification changes the number
Certification is not a badge you buy once for a brand. It attaches to a model and, in practice, to a specific configuration. That is why two suppliers can both say "certified" and mean different things.
What this looks like from our side, stated the way we would want it stated to us:
- For the confirmed SH-Home-10 and SH-Home-16 configurations we hold an EN IEC 62619:2022 verification of compliance, together with the UN 38.3 test summary, the MSDS and the sea-transport appraisal for the dangerous-goods declaration.
- Read the first line carefully, because the wording is the whole point: that document is a verification of compliance issued by a testing laboratory. It is not an accreditation certificate from a certification body, and it does not carry the mark of one. Suppliers who call it "IEC certification" are describing something they may not hold.
- The document names the model. It does not state capacity, energy or power output — those come from the datasheet, and a buyer should check them there rather than on a certificate.
- Where we cannot produce a file for a model, we write Not held rather than implying cover through the family name. Transport documents travel with each shipment.
A quote that carries the words "IEC certified" without naming the model, the standard and the file is a line you cannot audit. Ask for the model, the standard number and who holds the report. If the answer is a family brochure, the certification is not yet evidence — and it should not be priced as if it were.
For grid connection in South Africa, the sequence matters as much as the document. NRS 097-2-1 is answered per model, and the application itself is decided by the local authority with a registered electrician. A supplier provides documents and answers questions; it cannot approve a connection.
4. Landed cost: Incoterm, duty, port and insurance
Two quotes can name the same product and the same Incoterm and still land at different costs, because the Incoterm decides who pays which charge at which point.
Before comparing, write down four things:
- The Incoterm and the named place — "CIF" without a port is not a term.
- What is excluded — port handling, clearing agent, demurrage risk, inland transport.
- Insurance — who insures, at what cover, and who claims if a pallet arrives damaged.
- Dangerous-goods handling — lithium batteries are regulated for transport, and the carrier decides what it will accept. Handling is a cost line, not a formality.
For the import file itself, the documentation guide covers what a shipment needs. Rates and duties change, and they are decided at the border — check them at the time of shipment, not from a quote written months earlier.
5. What a comparable quote must state
Send this list to every supplier. The quotes that come back can be compared; the ones that cannot answer it cannot.
6. Why the cheapest quote often costs more after commissioning
The gap rarely appears at purchase. It appears in three places afterwards.
Installation. A unit with an unusual terminal layout, an undocumented communication protocol, or a mounting requirement that does not match the site adds labour hours that were never in the cheap quote. The site pays for them, not the supplier. Our compatibility checks exist because this is where most of that labour comes from.
Commissioning. If the model's documentation does not match what the electrician needs for the connection application, the system sits finished but unapproved. That delay has a cost, and it is usually the customer's.
After the first failure. A warranty that is real in principle but undefined in practice — no RMA destination, no evidence list, no spare-parts path — turns a board failure into a stalled installation. The after-sales page describes how we structure that path, and the RMA evidence checklist lists what a claim actually needs.
7. FAQ
Why can two quotes for the same kWh differ so much?
Because the kWh figure is the only line both quotes share. Usable energy, inverter power and phase, cell batch and BMS, the certification actually held for that model, the Incoterm and the payment terms all move the number before any margin is added.
Should I compare price per kWh?
Only on usable kWh, and only after the rest of the scope matches. Nameplate kWh ignores depth of discharge and the reserve the system keeps, so a cheaper nameplate figure can deliver less energy per cycle.
Does certification change the price?
It changes what the supplier can support. Evidence is held per model, not per family: for the confirmed SH-Home-10 and SH-Home-16 configurations we hold an EN IEC 62619:2022 verification of compliance alongside the UN 38.3 test summary and MSDS. That document is a verification of compliance issued by a testing laboratory, not an accreditation certificate from a certification body — and it names the model, not the capacity.
Who approves grid connection in South Africa?
The local authority and a registered electrician, not the battery supplier. What a supplier can do is provide the model-level documents the application asks for and tell you how NRS 097-2-1 is answered for that model.
Where this fits
Market context for South Africa, including load shedding and import steps, is on the South Africa page. If you are still choosing between suppliers, start with how to choose a lithium battery supplier in South Africa. If you already have two quotes and want them read side by side, send both to the partner desk; model-by-model document status is on the documents centre.
Send two quotes for a comparison
Send the models, the two quotes and the destination port to jimmy@sunhongenergy.com, or message the desk on WhatsApp.
Scope
This guide explains what moves a solar battery quote. It contains no prices, no currency figures and no lead-time promises: pricing is confirmed in writing per model, quantity, Incoterm and destination. Certification statements describe the files held for the named models at the date of publication; where a model does not hold a certificate, this page says so.