BATTERY UPGRADES · EXISTING SOLAR · CEBU

Add a battery to your existing solar system.

If your rooftop solar goes dark in every brownout, the inverter is why: a grid-tie inverter must shut down when the grid fails. Whether yours can take storage depends on that box on your wall. Here’s how to tell, the three ways an upgrade is done, what has to match, and what the equipment costs in pesos.

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Your panels stay
Itemised peso prices
Dated sources

Same roof, new battery

The panels you already own charge a new battery by day. The battery carries the evening.

Solar energy
Battery backup

Illustration

The short answer

Usually yes, and your inverter decides how. A hybrid inverter can often take a compatible battery directly: the right voltage class, a battery management system it can talk to (CAN or RS485) and current firmware. A standard grid-tie (string) inverter can’t charge a battery at all, so you either AC-couple (keep it and add a hybrid inverter plus battery) or replace it with a hybrid. Microinverter systems are AC-coupled.

On our price list each 5.12 kWh LiFePO4 battery is ₱52,000, and a Deye single-phase hybrid, when one is needed, is ₱45,000–₱80,000. Installation and protection are priced after an inspection, and a change to a net-metered system goes through your utility first.

THE THREE UPGRADE PATHS

Three ways to add a battery to solar you already own.

Which one fits depends on the inverter you have, its age and size, and your supply. The panels stay in all three.

Path A · Direct battery

Your hybrid takes a battery

Fits when: Your hybrid's approved battery list includes a 48 V battery like ours, or your inverter is sold as battery-ready for its maker's own battery.
You buy: Batteries only: ₱52,000 per 5.12 kWh module on our list, if your inverter accepts it. A maker-only battery is quoted separately.
Watch for: The battery must be on the inverter's approved list: voltage class, BMS protocol and firmware. If the backup output was never wired, a backup panel is added.

Path B · AC coupling

Keep your inverter, add a hybrid

Fits when: A healthy grid-tie inverter or microinverters, roughly under 8 years old, with an AC output up to 10 kW.
You buy: A Deye hybrid plus batteries: from ₱97,000 of equipment.
Watch for: Your inverter must cut back when the hybrid shifts the frequency (set for 60 Hz), and its output can't exceed the hybrid's rating. Charging passes through two inverters.

Path C · Replace with a hybrid

Swap the inverter, keep the panels

Fits when: The inverter is old, faulty or out of warranty, or too large to AC-couple.
You buy: A Deye hybrid plus batteries: from ₱97,000 of equipment.
Watch for: Your strings must fit the hybrid's 150–425 V MPPT window (500 V max), and the array its PV input: 8–16 kWp, depending on model.

New equipmentWhat you keepSchematics, not wiring diagrams.

Paths B and C both buy a Deye hybrid plus batteries, but they size it differently. AC coupling keeps the old inverter working beside the hybrid, so the hybrid has to be at least as large as that inverter’s AC output. A replacement retires the old inverter and moves the panel strings onto the hybrid, which only has to take your panels on its PV input, so it can be a smaller model. A smaller hybrid also caps how much solar reaches the house and grid at midday, which we weigh in the design. If you’re still working out what “hybrid” means day to day, our on-grid vs hybrid vs off-grid guide compares how each system behaves in a brownout.

Not sure which path is yours? Seven questions about your inverter, size and backup goal give you the likely path, battery count and an equipment budget.

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COMPATIBILITY

What has to match before a battery goes in.

Ten things decide whether a battery works with the equipment you have. None of them can be judged from the brand alone.

Compatibility checklist for adding a battery to an existing solar system
What has to match	Why it matters	What we check	Paths
Inverter type	Only a hybrid or battery-ready inverter has a battery input. A grid-tie inverter has none.	Model and datasheet, from the side label.	All
Battery voltage class	Deye’s single-phase hybrids take 40–60 V (48 V class) batteries. Some inverters take only their maker’s high-voltage battery.	The battery input range on the datasheet.	A
Battery chemistry	Lithium (LiFePO4) and lead-acid batteries charge differently, so the inverter’s battery-type menu and charge settings must match the chemistry.	The battery type set in the inverter, and the battery’s datasheet.	A
BMS communication	The inverter reads the battery’s charge and limits over CAN or RS485, using a protocol from its approved battery list.	The battery on the approved list, and the protocol set in the battery menu.	A, B, C
Firmware	Battery support and AC coupling depend on it. Deye notes that its micro-inverter input’s on/off control by battery charge works only on certain firmware versions.	Versions on both inverters, updated before commissioning.	A, B
AC rating	In AC coupling, the existing inverter’s output must not exceed the hybrid’s rated output.	The nameplate AC rating against a 5, 6, 8 or 10 kW hybrid.	B
Frequency response at 60 Hz	With a full battery in an outage, the hybrid raises the frequency so the old inverter cuts back. One that doesn’t respond could keep feeding a full battery, which is why Solis, for example, requires coupled inverters to support over-frequency load shedding.	Frequency-watt settings for the Philippines’ 60 Hz grid. We check your model and don’t publish setpoints.	B
String voltage	A replacement hybrid has its own input window: 150–425 V MPPT, 500 V maximum.	Each string’s voltage and panel count.	C
Supply phase	Our hybrids are single-phase. Some makers’ AC coupling works only with three-phase inverters.	Main breaker, meter and which phase the backup loads sit on.	All
Warranty	Added equipment may affect the old inverter’s warranty. Terms vary by maker.	Ask the maker in writing. Terms for our equipment are confirmed in your proposal.	A, B

Where upgrades get complicated

Older inverters

Units around 8–10 years old, or out of warranty, may lack adjustable frequency-watt control. Replacing them with a hybrid is usually simpler than coupling to them.

Mismatched brands

Mixing makers works only inside each maker’s approved lists. A battery the inverter can’t talk to can’t report its charge or limits, and that is protection you lose.

Brand-only batteries

Some battery-ready inverters take only their maker’s high-voltage battery and backup unit. It can be the neatest route, but those batteries tend to cost more, and local availability varies.

60 Hz settings

Deye’s manual examples are written for 50 Hz grids. Every frequency setting has to suit the Philippines’ 60 Hz grid and both inverters’ limits, so nobody should copy values from a manual.

Warranty position

Adding a hybrid beside an inverter that’s still under warranty is a question for its maker. Ask before work starts, and get the answer in writing.

Three-phase homes

Our hybrids are single-phase. A three-phase supply needs a design that decides which phase the backup loads sit on, so we quote it after a site visit.

Know your inverter model? Send it with your request and we’ll check its datasheet against this list before we visit.

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ESSENTIAL-LOAD BACKUP

The battery runs a backup panel, not the whole house.

Only circuits moved to the hybrid’s LOAD output stay on in a brownout. Choosing them is the biggest design decision in an upgrade.

Before and after a battery upgrade

01 / 04

One home, before and afterNot a real installation

Before: panels and a grid-tie inverter, dark in an evening rotation.

Solar energy
Battery backup
Grid

Illustration

Chapter 01

6:00 P.M. · ROTATION, BEFORE THE UPGRADE

The panels are there, but the house is dark.

A grid-tie inverter must switch off when the grid fails. This anti-islanding rule protects line crews. By 6 p.m. the panels make little anyway, so everything on the main panel goes dark until the grid returns.

Grid-tie inverter: Shuts down for the outage, by design.
What stays on: Nothing on the house circuits.

The gap an upgrade closes

At your pace. Select any chapter.

Usually on the backup panel

Refrigerator
Lights
Electric fans
Wi-Fi router and modem
TV and a few outlets for laptops and phones
Optional: one bedroom aircon, on its own breaker

Usually left on the main panel

Shower water heaters
Oven, induction cooker and kettle
The other aircons
Water pump, unless it’s sized in

Typical choices, not rules. Your list and the inverter’s rating decide.

Circuits move; rooms aren’t rewired
The chosen breakers move from the main panel to a new backup sub-panel fed from the hybrid’s LOAD output, labelled so everyone knows what stays on.
Sized for the outage, not the sunny day
With the grid up, LOAD circuits can draw up to the hybrid’s grid passthrough limit (40–50 A on Deye’s 8 and 10 kW models, per their datasheet). In an outage they’re limited to the inverter’s rating and about 2.6 kW per battery module.
AC coupling moves one more connection
The old inverter’s output moves from the main panel to the hybrid’s GEN port, so its solar can charge the battery and keep the backup panel running by day.
Tested with the grid side off
The switch to battery happens in milliseconds, so lights, fans and Wi-Fi typically don’t notice. Desktop PCs and network storage should still sit on a small UPS.

For appliance-by-appliance runtimes, try the simulator in our battery backup guide. For how a solar home runs from morning to night, walk through how solar works, step by step.

HOW MUCH BATTERY

Size the battery for what you back up, not for your panels.

A 5 kWp and a 10 kWp system need the same battery if they back up the same circuits. The panels decide how fast it refills.

1 battery · essentialsFridge, fans, lights, Wi-Fi, TV · about 0.5 kW
7.4 hours
2 batteries · essentialsThe same list, through a full night
15 hours
1 battery · essentials + 1 HP airconAbout 0.9 kW at night
4.1 hours
Not recommended: little power headroom for the aircon’s start-up.
2 batteries · essentials + 1 HP airconAbout 0.9 kW at night
8.2 hours

Estimates on our cautious basis: 3.69 kWh delivered per 5.12 kWh battery (80% usable × 90% conversion) and no solar recharge during the outage. Red-alert windows from 2026 examples (5–9 p.m. on 15 May, 3–8 p.m. on 11 Aug, 1–10 p.m. on 3 Sep); a single area’s rotation lasted about an hour.

Energy sets the hours

Each battery delivers about 3.69 kWh on our cautious basis, roughly 7 hours at 0.5 kW. Fewer watts running means more hours.

Power sets what runs together

A 50 A module supplies about 2.6 kW continuously, and the inverter has its own rating. That’s why an aircon gets two batteries. Aircons also need 2–3 minutes before restarting, so pick one with a restart delay.

Your panels set the refill

Cebu averages about 3.7 kWh per kWp a day. Refilling one battery from its reserve takes about 4.6 kWh, so a 3 kWp system (about 11.1 kWh a day) refills one comfortably, while two leave little for the house on an average day.

Long outages after a typhoon

A battery refills on every day the sun shows, but it won’t carry a house for days. For long cloudy spells, a generator still has a place: see solar battery vs generator. On a Deye hybrid the GEN port does one job at a time (generator input, smart load or AC-coupled inverter input), so if your old inverter uses it, plan any generator connection at the design stage.

ELECTRICAL & SAFETY

What a safe upgrade includes.

A battery adds a DC source that stays live when the grid and panels are off. Look for these items in any upgrade quote.

Sealed plans and a permit
Under RA 7920, electrical plans must be signed and sealed by a Professional Electrical Engineer, and a permit secured, before installation. For net-metering work the 2026 joint circular gives the LGU 3 working days for the electrical permit and 7 for the final inspection certificate (CFEI).
Battery-side DC protection
The battery stays energised with the grid and panels off, so it gets its own breaker or fuse and isolator, sized with the cable for the hybrid’s battery current: 120 A to 210 A on the Deye 5–10 kW models, according to their datasheets.
Modules wired the maker’s way
Several modules are paralleled as the battery maker specifies for the inverter’s size. Deye’s 5.12 kWh module manual, for example, allows simple daisy-chaining only up to a 3.6 kW inverter and warns that overloading the first battery’s connectors overheats them.
Breakers and a labelled backup panel
The LOAD output feeds its own sub-panel with its own breakers. AC and DC disconnects are accessible and labelled, so anyone can isolate the system safely.
Earthing and surge protection
Frames, rails and enclosures are earthed, and surge protection is coordinated with the earthing. Some Deye hybrid variants have Type II surge protection built in on both sides; exposed and coastal sites usually justify external protection too.
A cool, dry, high spot
Deye hybrids are IP65 but reduce output above 45 °C. The inverter and battery go somewhere shaded and ventilated, and above flood level rather than in a ground-floor garage. Our typhoon-ready installation guide covers storm-season siting.

Work follows the Philippine Electrical Code 2017, whose solar PV article applies to systems with or without batteries. Any modification to a net-metered system is also an application to your utility (below).

WHAT IT COSTS

Upgrade equipment, priced line by line.

Equipment at our list prices before any promotion, from the same price list as our calculator. Labour and protection follow the inspection.

Equipment for a battery upgrade at our list prices (5.12 kWh LiFePO4 batteries; Deye single-phase hybrids)
Hybrid inverter	1 battery	2 batteries	3 batteries
No new inverterYour hybrid takes the battery (path A)	₱52,000	₱104,000	₱156,000
Deye SUN-5K-SG04LP1 · 5 kWAC coupling: an inverter up to 5 kW AC. Replacement: up to 8 kWp of panels	₱97,000	₱149,000	₱201,000
Deye SUN-6K-SG04LP1 · 6 kWAC coupling: an inverter up to 6 kW AC. Replacement: up to 9.6 kWp of panels	₱102,000	₱154,000	₱206,000
Deye SUN-8K-SG05LP1 · 8 kWAC coupling: an inverter up to 8 kW AC. Replacement: up to 12.8 kWp of panels	₱117,000	₱169,000	₱221,000
Deye SUN-10K-SG05LP1 · 10 kWAC coupling: an inverter up to 10 kW AC. Replacement: up to 16 kWp of panels	₱132,000	₱184,000	₱236,000

Two batteries are highlighted because they cover a night of essentials, and we recommend two whenever an aircon is on backup. Battery modules are ₱52,000 each; hybrids are ₱45,000 (5 kW), ₱50,000 (6 kW), ₱65,000 (8 kW), ₱80,000 (10 kW). VAT treatment and warranty terms are confirmed in your proposal.

Not in these figures

Priced after the inspection and listed in your proposal:

Installation labour
Battery breaker, isolator and cabling
Backup sub-panel and moving the chosen circuits
Earthing and surge-protection checks or upgrades
Sealed plans, the LGU electrical permit and CFEI
Utility paperwork for the modification
Re-stringing, if a replacement hybrid needs it

Published ranges elsewhere

Solaready lists 5 kWh LiFePO4 add-ons at ₱80,000–₱120,000 and 10 kWh at ₱150,000–₱220,000, figures that “may or may not include the hybrid inverter”, and says an inverter replacement or inverter-charger can add ₱30,000–₱80,000 (article dated “Aug 7”, year not shown; read 16 Oct 2026). These aren’t like-for-like with the equipment prices above, which exclude installation.

Why evening use beats export

Exported solar is credited at your utility’s generation charge, not the full rate. Our calculator assumes 55% of the retail rate, the cautious end of the 54–67% seen across Cebu utilities in Sep–Oct 2026. At VECO’s ₱14.89/kWh (Sep 2026), each kWh the battery delivers in the evening, instead of exporting its charge, is worth about ₱5.79 more on the bill after battery losses (90% conversion). That is an estimate, not a promise of savings.

Comparing upgrade quotes? Check that each one names the inverter model, states the battery’s usable kWh and lists every protection item. Our guide to comparing solar quotes goes line by line.

Small or ageing system? Compare an upgrade with a complete new solar + battery system. The calculator prices one, itemised, in about 30 seconds.

Price a new solar + battery system

NET METERING & CEBU

Tell your utility before the battery goes in.

The rules allow net metering with or without a battery. They also treat a change to your system like a new application.

“Any modification to an existing RE system shall require the QE to undergo the same process as that of a new customer.”
ERC Resolution No. 15, s. 2025, net-metering rules §12. The agreement template adds: “including the execution of a new Net-Metering Agreement.”

Adding generating capacity or replacing generating equipment “requires the approval of CEBECO I”.
CEBECO I net-metering application form

Adding a battery or swapping the inverter plausibly counts as a modification. The same rules confirm that systems qualify “with or without battery” (§6), so storage doesn’t cost you net metering. How VECO, MECO and the CEBECOs handle battery retrofits in practice isn’t published, so confirm it with your utility before work starts.

The process limits are short on paper: 3 working days for the LGU electrical permit and 7 for the CFEI, then 10 working days at the utility while the energy emergency under EO 110 lasts (20 under the rules otherwise). Those are legal limits, not promises; real timing depends on complete documents. Not net-metered yet? Start with our net-metering guide for Cebu.

Why a battery matters in Cebu now

Cebu’s 2026 red-alert windows mostly ran into the evening, when panels produce little. A battery fills that gap. Without one, a grid-tie system shuts down in any outage, even at noon.

123Grid alerts, 1 Jan–3 Sep 202693 yellow and 30 red on the Visayas grid (NGCP, via Daily Tribune)

≈1 hPer rotation, per areaVisayan Electric rotations, May 2026

3–9 hRed-alert windowsMostly late afternoon and evening, May–Sep 2026

2028When the fix is expected“It will be a 2028,” Energy Secretary Garin (SunStar, 12 Oct 2026)

SunStar’s report of the October 2026 Cebu energy summit said the Visayas will likely keep facing supply shortages through 2027.

STRAIGHT ANSWERS

Battery upgrade questions, answered straight.

What owners of existing systems ask before adding storage.

More guides: all solar guides for Cebu, including battery backup for brownouts.

01Can I add a battery to my existing grid-tie solar system?

Yes, but not to the grid-tie inverter itself. A string (grid-tie) inverter has no battery input, so the battery arrives with a hybrid inverter. Either the hybrid is AC-coupled beside your current inverter, which keeps working, or it replaces it and your panels move onto the hybrid.

On our price list the smallest version of either route is a 5 kW Deye hybrid and one 5.12 kWh battery: ₱97,000 of equipment. Installation, protection, the backup panel and paperwork are confirmed after a site inspection.

02Can I convert my grid-tie inverter into a hybrid?

Not with a setting or a software update. A hybrid inverter has battery terminals, a battery charger and a separate backup (LOAD) output, and a grid-tie inverter has none of them. In practice, "converting" means adding a hybrid (AC coupling) or swapping one in.

Some string inverters are sold as battery-ready for their maker's own battery. That is model-specific, so we check it from the label on your inverter.

03Will adding a battery affect my net metering?

Net metering allows systems with or without battery storage, so a battery doesn't disqualify you. But the ERC's 2025 rules say any modification to an existing system goes through the same process as a new customer, including a new net-metering agreement, and a new battery or inverter plausibly counts as one.

Tell VECO, MECO or your CEBECO before the work. Each utility's handling of battery retrofits isn't published, so confirm it for your account. The legal processing limits are short (10 working days for the utility while EO 110 is in force, 20 under the rules otherwise), but real timing depends on complete documents.

04How many batteries should I add to a 5 kW system?

Size the battery by what you'll back up, not by the panels or inverter. One 5.12 kWh battery delivers about 3.69 kWh on our cautious basis: around 7 hours of a fridge, fans, lights, Wi-Fi and TV at about 0.5 kW. Two cover a night of essentials, and we recommend two whenever an aircon is on backup.

The array matters for refilling. A 5 kWp system makes about 18.5 kWh on an average Cebu day, and refilling two batteries from their reserve takes about 9.1 kWh of it.

05Do I have to replace my solar panels?

No. The panels stay in every path. With AC coupling nothing on the roof changes. With a replacement hybrid the strings are reconnected to it, and may need re-arranging to fit its input window (150–425 V MPPT and 500 V maximum on the Deye single-phase models). Panel, connector and cable condition are checked before anything is re-terminated.

06Will AC coupling void my current inverter's warranty?

That depends on the maker's terms, and only the maker can answer for them. Ask your installer or the maker before the work, in writing if you can. We check whether your model supports the frequency control AC coupling relies on. Warranty terms for the hybrid and batteries we supply are confirmed in your proposal.

07Can I use any 48 V lithium battery with my hybrid inverter?

No. The battery has to be one the inverter supports: the right voltage class (Deye's single-phase hybrids use 48 V low-voltage batteries; some other inverters take only their maker's high-voltage battery), a battery management system that talks to the inverter over CAN or RS485, and matching firmware. Deye, for example, selects the battery by its BMS protocol code from an approved battery list. We only pair batteries the inverter supports.

08I have microinverters. Can I still add a battery?

Yes, through AC coupling. Microinverters produce AC on the roof, so a Deye hybrid takes their output on its GEN port (its "Micro Inv Input" mode) and charges the battery from it. The microinverters must respond to the hybrid's frequency shift, and their combined output must stay within the hybrid's rating. Deye notes that this input's on/off control by battery charge works only on certain firmware versions, so we check the firmware, the frequency response and the combined output before we quote.

THREE WAYS TO MOVE FORWARD

Your system, plus a battery,
planned properly.

Request an upgrade quote with your inverter details, price a complete new backup system for comparison, or ask a question first. No obligation either way.

Route B

Request a battery upgrade quote

Share a few details and we’ll prepare a proposal after a site assessment.

Request my quote Route A

Instant estimate

Your system, installed price and savings in about 30 seconds. No contact details needed.

Start the calculator Route C

Ask an advisor

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ROUTES B & C · TALK TO US

Prefer a quote or a conversation?

Every quotation follows a site assessment of your roof, wiring and priorities, so the price you approve is the price of the system you get.

Request a battery upgrade quote

Tell us what you have. We check your inverter’s datasheet first, then confirm the path and the price after a site inspection.

Ask a solar advisor

Not ready for a quote? Ask about adding a battery to your solar system and we’ll reply by phone or email.

ROUTE A · INSTANT ESTIMATE

Get your own estimate.

The same calculator and prices as the rest of the site. Your estimate stays on your screen unless you ask us to contact you.

Let’s start with your electricity bill.

Choose your usual monthly bill. An estimate is all you need.

Using VECO at ₱14.89/kWh · Sep 2026. You can change your provider later.

About 30 seconds · No obligation

Sources & assumptions

Reviewed 16 October 2026 · Paths, runtimes and budgets are estimates until a site inspection

Deye SUN-5K/6K-SG04LP1-EU user manual (file dated 27 Apr 2026) (opens in a new tab)
GRID, LOAD and GEN ports; GEN-port “Micro Inv Input” for micro-inverters or other on-grid inverters, its on/off control by battery charge “valid for some certain FW version only”; lithium battery selection by BMS protocol code from the approved battery list; 50 Hz examples; aircon restart delay. Accessed 16 Oct 2026.
Deye SUN-3/3.6/5/6K-SG04LP1-EU datasheet (file dated 11 Sep 2026) (opens in a new tab)
40–60 V battery input; 120/135 A battery current; Max PV input 8,000/9,600 W; PV 500 V max, MPPT 150–425 V; 50/60 Hz; anti-islanding. Accessed 16 Oct 2026.
Deye SUN-3.6–10K-SG05LP1-EU-SM2-P datasheet (6 Jul 2026) (opens in a new tab)
8 kW and 10 kW models: 190/210 A battery current; Max PV input 12,800/16,000 W; 40–50 A grid passthrough; IP65, derating above 45 °C; Type II DC and AC surge protection on this variant; “AC couple to retrofit existing solar system”. Accessed 16 Oct 2026.
Deye SE-G5.1 LiFePO4 battery user manual v03 (18 Mar 2026) (opens in a new tab)
5.12 kWh module: 80% recommended depth of discharge, 50 A maximum (about 2.6 kW), CAN and RS485; daisy-chain parallel mode only up to a 3.6 kW inverter, with an overheating warning. Used as our cautious runtime basis until the exact module is confirmed. Accessed 16 Oct 2026.
Solis support: AC-coupling with the Solis S6-3P hybrid inverter (modified 1 Oct 2026) (opens in a new tab)
A coupled PV inverter “must support over-frequency load shedding”; PV inverter AC power not above the hybrid's rated AC power; firmware updated before commissioning; three-phase only for that product.
Huawei SUN2000-2–6KTL-L1 datasheet (v01, Oct 2024) (opens in a new tab)
Battery-ready single-phase inverter listed with Huawei's own LUNA2000 high-voltage batteries; backup through Huawei's backup unit. Read from the published summary, as the page is script-rendered.
Philippine Grid Code, 2016 Edition (ERC Resolution No. 22, s. 2016) (opens in a new tab)
“The nominal fundamental Frequency shall be 60 Hz.”
ERC Resolution No. 15, s. 2025: Amended net-metering rules (copy hosted by Visayan Electric) (opens in a new tab)
§6: eligible “with or without battery”; §12: a modification follows the new-customer process; the agreement template adds a new net-metering agreement. Issued 27 Aug 2025.
CEBECO I net-metering programme: checklist and application form (opens in a new tab)
The form states that adding generating capacity or replacing generating equipment requires CEBECO I's approval. Files dated Sep 2025 to Apr 2026.
DOE, “The 5 Ws of Net-Metering” primer (Sep 2022) (opens in a new tab)
Net metering up to 100 kW, “with or without battery energy storage”.
DOE–DILG–DPWH Joint Memorandum Circular No. 001, s. 2026 (13 Jan 2026) (opens in a new tab)
Electrical permit within 3 working days and CFEI within 7 for net-metering applications.
DOE: net metering fast-tracked under EO 110 (1 Apr 2026) (opens in a new tab)
Utilities: 10 working days, non-extendible, for the duration of the energy emergency (EO 110, signed 24 Mar 2026 for one year unless extended or lifted).
Republic Act No. 7920, New Electrical Engineering Law (1995) (opens in a new tab)
§34: no electrical installation without plans signed and sealed by a Professional Electrical Engineer and a permit.
Filipino Engineer, Technical Note: Rooftop Solar PV Systems in the Philippines (13 Nov 2025, updated 7 Mar 2026) (opens in a new tab)
Secondary summary of PEC 2017 Art. 6.90: disconnects and labelling, grounding of metallic parts. Confirm clauses against the IIEE text.
Solaready, “Can You Add a Battery to an Existing Grid-Tie Solar System?” (“Aug 7”, year not shown) (opens in a new tab)
Published add-on ranges: 5 kWh ₱80,000–₱120,000 and 10 kWh ₱150,000–₱220,000, which “may or may not include the hybrid inverter”; inverter replacement or inverter-charger ₱30,000–₱80,000. Accessed 16 Oct 2026.
PVGIS 5.3 (EU JRC), Cebu City, run 16 Oct 2026 (opens in a new tab)
About 1,367 (roof-flush) to 1,420 (free-standing) kWh per kWp a year. For the recharge check we use a cautious 3.7 kWh per kWp per day (1,350 a year).
Daily Tribune, “Visayas grid logs 123 alerts as supply falters” (3 Sep 2026) (opens in a new tab)
93 yellow and 30 red alerts, 1 Jan–3 Sep 2026 (NGCP); red alert 1–10 p.m. on 3 Sep.
BusinessMirror, “Cebu rotational brownouts on 3rd day to avert Visayas grid collapse” (15 May 2026) (opens in a new tab)
About one hour per area; red alert 5–9 p.m. on 15 May.
Philstar, “Visayas grid on extended red alert” (12 Aug 2026) (opens in a new tab)
Red alert from 3 to 8 p.m. on 11 Aug 2026.
SunStar, “Power risks persist” (12 Oct 2026) (opens in a new tab)
Reporter's summary: shortages likely through 2027. Energy Secretary Garin, verbatim: “it will be a 2028”.
Visayan Electric newsroom: monthly rate announcements (opens in a new tab)
The export example uses VECO (Visayan Electric)'s ₱14.89/kWh residential rate (Sep 2026) from our monthly-updated rate table, and our calculator's cautious 55% export credit.

YOUR PANELS ARE ALREADY UP

Keep the panels.
Add the evening.

Send us your inverter model and system size. We’ll check compatibility, confirm the path on site and give you an itemised upgrade price.

Get my battery upgrade quote Check my upgrade options

YOUR NEXT QUESTION

Each guide answers one question properly, with the numbers and sources behind it.

Add a battery to your existing solar system.

Three ways to add a battery to solar you already own.

Which upgrade fits your system?

Keep your inverter, add a hybrid and battery

What has to match before a battery goes in.

Where upgrades get complicated

Older inverters

Mismatched brands

Brand-only batteries

60 Hz settings

Warranty position

Three-phase homes

The battery runs a backup panel, not the whole house.

The panels are there, but the house is dark.

A hybrid, a battery and a small backup panel.

The backup panel stays on.

Your panels refill the battery first.

Usually on the backup panel

Usually left on the main panel

Circuits move; rooms aren’t rewired

Sized for the outage, not the sunny day

AC coupling moves one more connection

Tested with the grid side off

Size the battery for what you back up, not for your panels.

Energy sets the hours

Power sets what runs together

Your panels set the refill

What a safe upgrade includes.

Sealed plans and a permit

Battery-side DC protection

Modules wired the maker’s way

Breakers and a labelled backup panel

Earthing and surge protection

A cool, dry, high spot

Upgrade equipment, priced line by line.

Not in these figures

Tell your utility before the battery goes in.

Why a battery matters in Cebu now

Battery upgrade questions, answered straight.

Your system, plus a battery,planned properly.

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Let’s start with your electricity bill.

Sources & assumptions

Keep the panels.Add the evening.

Keep planning

Battery backup for brownouts

On-grid vs hybrid vs off-grid

How to compare solar quotes

Your system, plus a battery,
planned properly.

Keep the panels.
Add the evening.