How to Price a Home Battery Storage Installation: Labour, Materials and Margin Guide

Summary

Battery storage has moved from an early-adopter add-on to a mainstream retrofit product, and the technical requirements are well covered in battery storage — DNO notification thresholds, fire safety separation, and the new BS 7671 Chapter 57 rules. What that article doesn't cover, and what actually determines whether a battery job is profitable, is how to price the labour, materials and margin correctly, and where installers most commonly leave money on the table or absorb costs they should have quoted for.

This guide is written for the person doing the quoting, not the person doing the technical install. It breaks down realistic day rates, typical hardware costs by system size and chemistry, where DNO notification (G98 vs G99) affects programme and price, and the specific red flags — fire compartment relocation, undersized existing consumer units, cable run length to a compliant location — that turn a straightforward-looking battery job into a loss-making one if they're missed at the quoting stage.

Pricing this work well matters more than it used to. Since BS 7671:2018+A4:2026 introduced Chapter 57 and PAS 63100:2024 formally prohibited loft, bedroom, and unprotected escape route locations for battery systems, a meaningful share of "simple" battery retrofits now involve relocating cable routes or specifying a fire-rated enclosure that wasn't needed under the previous rules — and that additional scope needs to be priced, not absorbed.

Key Facts

• Typical 2-person installer day rate — roughly £280-£450/day combined for an MCS-certified electrician and mate, varying by region (London/SE at the top of the range)
• AC-coupled retrofit install time — typically 1-2 days for a straightforward retrofit onto an existing solar PV system with a compliant consumer unit already in place
• DC-coupled hybrid install time — typically 2-3 days where the existing PV inverter is being replaced with a hybrid unit, plus additional commissioning time
• Battery unit cost (hardware only) — roughly £2,500-£4,500 for entry-level 5kWh systems, rising to £6,000-£9,000+ for 10-13.5kWh systems, with LFP chemistry typically commanding a 10-20% premium over NMC for the same usable capacity
• Hybrid inverter cost — roughly £900-£2,000 supplied, where an inverter swap is needed as part of the install
• Mounting, enclosure and cabling extras — fire-rated enclosure or relocation work (where PAS 63100:2024 rules out the customer's preferred location), DC isolators, additional cable run length, and any consumer unit upgrade (RCBO board, SPD) should each be priced as separate line items, not folded silently into the headline battery price
• G98 notification — no direct DNO fee in most cases, but budget genuine admin time (form completion, technical parameter setting) rather than treating it as free
• G99 approval — used for larger systems (>16A per phase, or any three-phase installation); can take up to 45 working days and may incur a DNO assessment or reinforcement cost that should be flagged to the customer as a programme risk before work starts, not discovered mid-job
• MCS certification overhead — the ongoing cost of maintaining MCS certification (needed for Smart Export Guarantee eligibility on combined solar+battery jobs) should be amortised into the hourly/day rate rather than ignored, since it's a genuine cost of being able to do this work at all
• Typical gross margin on hardware — 20-35% is a reasonable range for battery unit and inverter markup; labour and commissioning time should be charged separately at the day rate rather than baked into an inflated hardware price
• BS 7671:2018+A4:2026 Chapter 57 / PAS 63100:2024 compliance cost — location prohibitions (no lofts, bedrooms, or unprotected escape routes) mean a growing share of retrofits need a longer cable run to a compliant location (garage, utility room, external wall), which is a real cost driver that should be assessed on-site before quoting, not assumed away
• Callback/warranty reserve — a small margin allowance for commissioning callbacks (BMS fault codes, inverter pairing issues) is standard practice and should be built into the price rather than treated as a free warranty visit that erodes the job's profitability

Quick Reference Table

Figures are indicative 2026 UK market ranges for planning purposes — always price from current supplier cost sheets and site-specific labour assessment rather than these ranges alone.

Detailed Guidance

Labour Cost Breakdown

A realistic labour quote for a battery installation should itemise, even if the customer only sees a single line total:

• Site survey and quotation time (often unbilled, but should be factored into overhead recovery in the day rate)
• Installation labour: mounting the battery, running/terminating DC and AC cabling, fitting or upgrading the consumer unit as needed, and physically siting the unit in a compliant location
• Commissioning: setting inverter export/import parameters for G98/G99 compliance, pairing the battery with the inverter and any app/monitoring platform, and testing charge/discharge behaviour
• Customer handover and training: a genuinely useful handover (how to read the app, what the BMS warning lights mean, who to call for a fault) takes real time and should be priced in rather than rushed at the end of a long installation day
• G98/G99 administrative time: completing and submitting DNO paperwork, and — on G99 jobs — managing the DNO approval timeline and any resulting delay conversation with the customer

Two-person crews are standard for battery installs given the weight of the units and the value of having a second person for testing/commissioning while the first completes physical fixing work.

Material Cost Breakdown

Beyond the headline battery unit price, a complete material cost breakdown includes:

• The battery unit itself (chemistry, usable capacity and brand-tier all affect cost — LFP generally costs more than NMC for equivalent usable capacity but is increasingly the default specification given its better thermal stability)
• Inverter (only where a hybrid inverter swap is part of the job; AC-coupled retrofits usually don't require this)
• DC and AC cabling, appropriately rated and, where the compliant location is further from the consumer unit than the customer's preferred (but non-compliant) location, a longer run than initially assumed
• Consumer unit work: RCBO circuit for the battery inverter, and an SPD if the existing board doesn't already have one fitted (increasingly a requirement rather than an option)
• Fire-rated enclosure, non-combustible mounting surface, or minor building work where the compliant location under PAS 63100:2024 requires it
• Ventilation provision to outside air, where the chosen location doesn't already have it

Pricing by System Type

AC-coupled retrofit is the most common and most predictable job: adding a battery inverter to an existing solar PV system without touching the existing PV inverter. This is generally the lowest-labour, lowest-risk option to price, provided the existing consumer unit and cable routes are already compliant.

DC-coupled hybrid systems replace the existing PV inverter with a hybrid unit that manages both the panels and the battery on the DC side. This is more efficient long-term but adds inverter cost, additional commissioning complexity, and typically a half to full extra day of labour — price it as a materially different job, not a like-for-like swap of the AC-coupled quote.

Whole-house backup / EPS (emergency power supply) configurations, where the battery can island the property from the grid during an outage, require additional switching hardware and a more involved commissioning process, and should carry a distinct, higher price point reflecting that additional scope — don't quote this as a standard installation with "backup capability thrown in."

Margin and Markup Guidance

A 20-35% gross margin on hardware (battery, inverter, and associated electrical materials) is a reasonable starting point, with labour charged transparently at the day rate rather than disguised inside an inflated hardware price. This transparency matters for two practical reasons: customers increasingly compare quotes against publicly known hardware prices, and a clearly itemised quote is easier to defend if a customer queries the total or asks for a breakdown.

The most common margin killer on battery jobs isn't the hardware markup — it's underestimating commissioning time. Pairing a battery with an inverter, setting correct G98/G99 export parameters, and troubleshooting an app or monitoring platform connection routinely takes longer than a confident quote assumes, especially on the first few installs of a new product line. Build in a realistic commissioning time allowance rather than pricing based on the manufacturer's best-case install time.

Red Flags That Blow the Budget

• Fire compartment/location relocation — a customer's preferred location (loft, bedroom cupboard, under-stairs space) may now be formally prohibited under PAS 63100:2024, forcing a longer cable run to a garage, utility room, or external wall that wasn't accounted for in an initial ballpark quote
• DNO reinforcement or delay on G99 jobs — larger or three-phase systems needing G99 approval can be delayed up to 45 working days, and in some cases the DNO identifies a need for local network reinforcement at additional cost; flag this risk to the customer before committing to a fixed completion date
• Non-RCBO existing consumer unit — an older split-load or non-RCBO board may need upgrading before a compliant battery circuit can be added, which is a materially different (and more expensive) job than adding a circuit to an already-compliant board
• Underpriced ventilation or non-combustible surface work — treating the battery's location requirements as "the electrician's problem to sort on the day" rather than pricing minor building work into the quote upfront
• No callback/warranty reserve — commissioning issues (BMS fault codes, inverter pairing failures, app connectivity) are common enough on battery installs that a warranty callback allowance should be priced in rather than treated as free troubleshooting after the invoice is paid

Frequently Asked Questions

Why do quotes for what looks like the same battery vary so much between installers?

Largely because of what's included versus excluded. A quote that assumes the existing location is compliant, the consumer unit is already RCBO-ready, and no cable run extension is needed will look significantly cheaper than one that's priced a full PAS 63100:2024-compliant location from the outset — until the cheaper quote hits a site survey and the price changes. Itemising the quote clearly protects both the installer and the customer from this mismatch.

Should the DNO notification (G98/G99) be a separate line item?

Yes, particularly for G99 jobs where approval time and potential DNO reinforcement costs represent a genuine programme and cost risk that the customer should see and understand upfront, rather than discovering as a surprise delay partway through the job.

How much extra should I quote if the customer's preferred location isn't PAS 63100:2024 compliant?

This depends entirely on the site — a straightforward move from a cupboard to a nearby garage might add only a modest amount of extra cable and half a day's labour, while a location that requires a fire-rated enclosure or a long external cable run to reach a genuinely compliant space can add a significant proportion of the total job cost. Always assess this on-site before quoting a fixed price; a phone-based estimate on location compliance is one of the most common sources of a quote that doesn't survive the actual site visit.

Is retrofitting a battery to existing solar PV cheaper than a combined new solar + battery installation?

Per-project, yes — a retrofit avoids the cost of new PV panels, and often avoids a full inverter replacement if an AC-coupled battery inverter is used. However, a combined new-build solar + battery installation can be more cost-efficient per kWh of capacity delivered, since scaffold, DNO notification, and commissioning time are shared across both elements of the job rather than duplicated across two separate site visits months apart.

What warranty or callback provision should be built into the price?

A small allowance — commonly built into the margin rather than itemised separately to the customer — covering a return visit for commissioning-related issues (BMS warning codes, inverter/battery pairing faults, app or monitoring connectivity problems) in the weeks following handover is standard good practice, distinct from the manufacturer's product warranty which covers hardware failure over a longer term.

Regulations & Standards

• BS 7671:2018+A4:2026 Chapter 57 — Stationary secondary battery installations; the primary electrical installation standard, and a compliance cost driver where existing wiring or location doesn't already meet it

• PAS 63100:2024 — Fire protection of battery energy storage systems for use in dwellings; location prohibitions (lofts, bedrooms, unprotected escape routes) are a direct source of additional scope and cost on many retrofit jobs

• ENA Engineering Recommendation G98 Issue 2 (2025) — DNO notification for systems ≤16A per phase; the most common route and generally the lowest-cost/lowest-delay notification path

• ENA Engineering Recommendation G99 Issue 2 (2025) — DNO approval for larger or three-phase systems; the main source of programme risk and potential additional DNO-related cost on bigger installations

• Building Regulations Part P — notifiable electrical work for the new circuit required to power the battery inverter

• MCS certification (MIS 3012 and related standards) — required for Smart Export Guarantee eligibility on combined solar and battery installations; an ongoing business cost that should be reflected in day rates

• MCS — Microgeneration Certification Scheme — installer certification standards and requirements

• Ofgem — Smart Export Guarantee — Office of Gas and Electricity Markets

• ENA Engineering Recommendations G98 and G99 — Energy Networks Association

• BSI — PAS 63100:2024 — Fire protection of battery energy storage systems for dwellings

• battery storage — the technical installation guide covering DNO registration, fire safety, chemistry and BS 7671 Chapter 57 requirements this pricing guide builds on

• solar battery systems — combined solar PV and battery system design and certification overview

• solar pv installation pricing guide — pricing guide for solar PV installations, relevant where battery and solar are quoted together

• pricing labour — general day rate and labour pricing methodology applicable across electrical trades