Batteries

What do battery cycle life and depth of discharge mean for SA home solar?

Cycle life is how many charge/discharge cycles a lithium pack is rated for at a stated depth of discharge (DoD); deeper daily DoD under Stage calendars uses cycles faster, so size usable kWh and SoC floors together — not just the sticker kWh.

Updated 27 October 2026 · Illustrative ranges — not a formal quote, credit decision or legal advice.

Answer first: Ask for the OEM warranty PDF: cycles at a stated DoD, calendar years, and throughput (MWh) if listed. Size the pack so Stage windows do not force 90%+ DoD every evening — usable kWh · DoD hub · battery lifespan · batteries.

DoD and Stage calendars

A pack that barely covers a Stage 4 evening at 90% DoD will rack cycles during a bad month. A larger usable bank at 60–70% DoD often lasts more calendar years for the same lifestyle — Stage 4 · SoC · Stage table.

Numbers to request

Ask	Why
Cycles @ DoD	Compare apples to apples
Calendar years	Whichever-first warranty
Throughput MWh	Some OEMs use energy throughput
Usable kWh at end of warranty	Retention %, not just years

Peers include Solar MD, Hubble, BlueNova and others — compare the PDF, not the brochure line. Soft peer language only; named facts win — warranty checks · claim steps.

Settings that protect cycles

Raise overnight SoC floors before predicted Stage clusters.
Prefer self-use over aggressive export if your tariff does not pay well.
Keep firmware current so BMS limits match the warranty letter.

export vs self-use · firmware · monitoring.

Desk close

Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins. Revisit after any Stage-calendar or tariff change — metro tariffs · tariffs 2026 · choose installer · get quotes · check a quote.

Sources homeowners can open

Your metro SSEG / tariff PDF (live municipal site).
OEM inverter and battery warranty PDFs for the quoted SKUs.
NERSA and municipal tariff schedules for the current year.
NRS 097 dual-supply labelling notes via your registered electrician.

Commissioning evidence pack

Before sign-off, collect serial photos, firmware version, export-limit screenshot, CT polarity photo, dual-supply label photos, CoC number, and the guest monitoring login. Store them with the invoice PDF — CoC · export limit · CT clamps · labels · firmware · warranty claims.

Tariff and fixed-charge reminder

Self-use savings sit on top of fixed charges that do not disappear when panels go up. Model both before celebrating a payback slide — fixed charges · monthly savings · export vs self-use · bill still high · costs & savings.

Safety do-not list

Do not DIY dual-supply boards or MC4 strings.
Do not bridge RCDs to stop trips.
Do not ignore isolation or earth-fault alarms.
Do not disable export limits to “get more power.”

DIY risks · earth leakage · MC4 · DC isolation · red flags.

Stage-weekend reality check

Model the worst Stage window you actually live through. Essentials first, then comfort loads. If the plant cannot cover fridge, lights, fibre and one work laptop through that window, resize before you chase export credits — essentials · Stage strategy · Stage 4 battery · SoC settings · load shedding hub.

Extra SA context

Keep this page next to your metro tariff PDF and the OEM warranty letter for the SKUs on your quote. When numbers disagree, the live primary wins. After any Stage-calendar change, revisit SoC floors and the essential board list — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about.

Extra SA context

Bill maths before hardware

Pull three months of kWh and rand from your bill or prepaid tokens. Compare that to the quote’s self-use assumption at your metro’s published rates — monthly savings · fixed charges · export vs self-use · export credit vs self-use rand · metro tariffs · costs & savings · check a quote.

DoD settings that trade backup for lifespan

Running 95% DoD every Stage shortens life versus a 80% DoD with a reserve. For TOU savings, shallow daily cycles plus a deeper Stage reserve is a common compromise. Put the DoD / SoC floors on the handover sheet.

Align DoD with the warranty’s stated test regime.
Recalibrate after firmware changes.
what is DoD · usable kWh · SoC.

Homeowner close-out for battery cycle life dod sa

Keep OEM and metro PDFs beside this answer. Confirm Incl. VAT line items, NRS-listed SKUs where relevant, and who owns paperwork after deposit. Compare two written scopes before you pay — read a quote · choose installer · check a quote · get quotes · costs & savings · metro tariffs.

Write the decision rule for this topic into the handover pack in one sentence the next owner can follow without calling you. Clear operating rules beat tribal knowledge when the first Stage 4 night arrives.

Quick questions

What is DoD?

Depth of discharge — how much of the pack you use each cycle. 90% DoD uses more of the pack than 50%.

Does Stage 4 burn cycles?

Daily deep cycles during heavy shedding use warranty cycles faster than shallow evening peaks.

Usable vs nameplate?

Always plan on usable kWh after DoD and inverter limits — see usable kWh desk.

Warranty cycles vs years?

Whichever comes first usually binds — read the OEM PDF.