Batteries

Solar battery cycles and warranty in South Africa explained

Q: Solar battery cycles and warranty in South Africa explained

A cycle is roughly one full charge-and-discharge of usable capacity. Warranties combine years with throughput/cycles and a remaining-capacity floor (e.g. ~70% after 10 years). Read all three and keep CoC plus operating-limit proof.

A cycle is roughly one full charge-and-discharge of usable capacity (manufacturers count partial cycles differently). Warranties usually combine calendar years with a throughput or cycle limit and a remaining-capacity floor (often ~70% after 10 years on residential LFP). Read all three — and keep install CoC, firmware and temperature proof if you ever claim.

Updated 26 October 2026 · Illustrative ranges — not a formal quote or legal advice.

Answer first: Cycle marketing and warranty years are not interchangeable. A residential LiFePO₄ pack might be advertised at 6 000 cycles while the warranty that actually pays out is 10 years or X MWh of throughput, whichever comes first, down to about 70% remaining capacity. Your bill savings come from daily self-use and load-shedding cover — not from chasing the highest cycle number on a brochure.

What a “cycle” means on a quote

Manufacturers define a cycle as moving a stated fraction of rated capacity (often near 100% of usable kWh, sometimes 80%). Partial discharges usually accumulate as fractional cycles. A house that drops the battery 30% every evening for load shedding and solar shift may take three nights to equal one full cycle. That is why a “6 000-cycle” pack can still be within warranty after a decade of normal SA use — if temperature, depth of discharge and charge rates stayed inside the manual.

Ask the installer to show the warranty PDF for the exact SKU, not a brand overview slide. Related: depth of discharge (DoD), LFP vs NMC.

Years vs throughput vs capacity floor

Clause	What it caps	Homeowner question
Calendar years	Time on the wall (often 5–12 years residential)	Does the clock start at install or delivery?
Cycles / throughput	Energy moved (full cycles or MWh)	Is daily solar shifting counted the same as deep shedding events?
Capacity floor	Minimum % of nameplate still usable	Is the claim measured at the terminals under a defined test?

Whichever limit you hit first usually ends the free remedy. Heavy daily cycling plus a small pack can burn throughput faster than calendar years; a lightly used oversized pack may age on the calendar first.

How this links to rand savings

Storage earns its keep by displacing retail grid kWh (often R3–R5/kWh on metro residential steps in 2026/27) and by keeping essentials up in shedding. Export credits are much lower — Cape Town ~152.93 c/kWh incl., City Power ~143.29 c, eThekwini ~184.60 c, Tshwane ~108.25 c — so cycling the battery to dump cheap midday PV into evening peaks usually beats exporting. See feed-in table and 2026 tariffs.

Over-cycling for tiny tariff wins (or running a geyser on backup every night) wears throughput without improving payback. Size for essential loads and self-use first — essential vs non-essential.

What commonly voids cover in SA homes

Wrong inverter protocol / unsupported BMS settings or parallel packs the brand did not approve.
Water ingress, incorrect torque, missing DC fusing or undersized cable.
Operating outside temperature limits (garages that hit 40 °C+ need airflow or a cooler site).
Unauthorised firmware, DIY capacity expansions, or grey-import cells without local RMA.
Missing CoC / as-built pack when the insurer or manufacturer asks for proof of correct install.

Buy through installers who source from reputable SA wholesalers so returns logistics exist. Named trade channels among peers include Soft Solar MD (local LFP longevity claims — verify against the warranty PDF) and wholesale desks such as SONAH — always compare peers on stock, RMA and price, never treat one badge as a soft #1.

Field questions before you pay a deposit

Exact model, usable kWh, rated cycles and warranty PDF URL or attachment.
Whether the warranty is pro-rata after year X or full replacement to the capacity floor.
Who carries labour for a module swap in year 7 (manufacturer, wholesaler or installer).
Compatible inverter list — compatibility FAQ.
Recommended DoD for daily use vs emergency reserve for Stage 4–6.

Cycle life vs calendar ageing

LFP chemistry ages with time and temperature even if you barely cycle it. A pack left at 100% state of charge in a hot outbuilding can lose calendar life while barely spending cycles. Installer settings that float at a lower daytime SoC when grid is stable often help; follow the brand app guidance rather than inventing DIY limits.

Lead-acid leftovers and “unlimited cycle” marketing

Older AGM/gel claims and some budget lithium marketing use soft language (“designed for 3 000+ cycles”) without a clear capacity floor. Treat those as engineering estimates, not bankable warranties. If the document does not name a remaining-capacity % and a claim process, price the pack as a consumable, not a 10-year asset.

SA caveats

Warranties are commercial contracts, not municipal approvals. NRS 097 and SSEG registration cover the grid interface — NRS 097 — they do not extend battery cover. Grey imports that fail SSEG desks also tend to fail warranty desks. This page is educational; read the PDF that ships with your serial numbers.

Quick FAQ

Does load shedding use more cycles? Yes if you discharge deeper and more often — that is the point of backup. Size kWh so Stage 4–6 essentials last without nightly 90% DoD — Stage 6 sizing.
Is 6 000 cycles “better” than 4 000? Only if DoD, temperature and warranty floor are comparable. A tighter capacity floor with fewer cycles can still be the stronger consumer contract.
Can I parallel different ages? Usually no — brands want matched packs. Ask before expanding in year 4.

Worked example — evening shift vs brochure cycles

Suppose a 10 kWh usable pack discharges 4 kWh every weeknight to cover evening cooking lights and ICT, then recharges from midday PV. That is about 0.4 of a full cycle per weekday, or roughly 100 full-equivalent cycles per year if weekends are lighter. Over 10 years you might accumulate ~1 000 full-equivalent cycles — well inside a 4 000–6 000 cycle marketing figure — while the calendar and capacity-floor clauses still govern whether a claim pays. The savings story is the avoided retail kWh each evening, not the unused cycle headroom.

If the same home also deep-discharges for Stage 4–6 twice a week, annual equivalents rise. That is acceptable when the pack was sized for it; it is painful when someone bought a 5 kWh unit and runs the geyser on backup nightly. Re-check DoD guidance in the app after the first month of real shedding.

Throughput warranties in MWh

Some brands express wear as total energy throughput (e.g. tens of MWh) instead of cycle counts. Convert roughly: throughput MWh ÷ usable kWh ≈ equivalent full cycles. Put both the MWh number and the years on your comparison spreadsheet so a “high cycle” pack with a tiny throughput cap cannot hide. Ask whether scrap capacity measurement requires a dealer visit and who pays travel.

Insurance and handover pack

Photograph serial labels, keep the CoC, SSEG letter, and warranty PDFs in one folder. After a storm claim, manufacturers often ask for install evidence before discussing cells. Pair with earthing and SPD so the physical install matches the paperwork story.