Battery Bank Sizing Calculator Pakistan

Most sizing calculators floating around online were built for American or European homes, priced in dollars, and built around 120V appliances that draw differently to what actually sits in a Pakistani living room. They get you close, and then they get you wrong in exactly the places that matter.

A few specific ways this shows up. Appliances here run on 220 to 240V rather than 110 to 120V, which changes typical current draw and sometimes the wattage figures a foreign calculator assumes by default. Refrigerator duty cycling is heavier in a country where ambient summer temperatures regularly sit above 40°C, so a compressor here runs longer and more often than the same model would in a temperate climate, and a calculator built around cooler conditions understates it. Battery bank voltage conventions differ too: most sizing tools abroad default to higher voltage banks that are uncommon in Pakistani residential installations, where 24V and 48V dominate. And a generic calculator has no idea what an itel 48V 100Ah or a 24V 200Ah actually holds, so it leaves you with a kWh figure and no bridge to an actual product on a shelf.

Below is a calculator built around that reality, followed by the manual method behind it so you can check the numbers yourself or work them out without a browser. No prices in this guide, since rates move weekly. Once you have your figure, WhatsApp us now for the latest price of the battery at 03192070022.

The calculator

Copy the code below into a Custom HTML block in WordPress, or hand it to whoever maintains the site. It runs entirely in the visitor’s browser, needs no server or plugin, and nothing typed into it is sent anywhere.

A couple of notes if you are the one embedding this. It uses no external libraries, so it will not conflict with your theme’s scripts. All class names are prefixed bbsc- specifically to avoid colliding with existing WordPress theme styles. If your WordPress editor strips <script> tags in the block editor, paste it into a Custom HTML block specifically rather than a paragraph block, which preserves it correctly.

The manual method, if you would rather work it out by hand

The calculator above is doing exactly this arithmetic, so here it is spelled out in case you want to sanity check the result or work without a browser.

Step one: list your appliances and their draw. Use real wattages rather than nameplate maximums where possible, since many appliances rarely run at their rated peak continuously.

Step two: multiply watts by quantity by hours of backup needed, for each appliance, to get watt hours.

Step three: add them all together for your total watt hours of actual appliance consumption.

Step four: divide by 0.85 to account for usable depth of discharge. A good LiFePO4 pack gives roughly 85 percent usable capacity, so if you need X watt hours delivered, you need X ÷ 0.85 watt hours of nominal battery capacity to have that much available.

Step five: divide again by 0.87 to account for roughly 13 percent inverter and wiring losses on the way from battery to appliance.

Step six: divide by 1000 to convert to kilowatt hours.

The formula in one line: nominal kWh needed = (total appliance watt hours) ÷ 0.85 ÷ 0.87 ÷ 1000.

Reference wattages for common Pakistani appliances

A more complete list than most calculators offer, for anything not covered by the tool’s presets.

Fans. A DC inverter ceiling fan draws roughly 25 to 75W depending on speed and model, with many modern DC fans sitting toward the lower end. An older AC ceiling fan draws closer to 70 to 100W. A pedestal or table fan is typically 50 to 75W.

Lighting. LED bulbs run 7 to 15W each depending on brightness. LED tube lights are typically 18 to 22W. Avoid sizing around older CFL or incandescent fixtures if you can help it, since they draw considerably more for the same light output.

Refrigeration. A single door inverter refrigerator averages 100 to 150W across a day once compressor cycling is accounted for. A double door or larger unit averages 150 to 250W. A chest freezer averages 100 to 200W depending on size and how full it is, since a fuller freezer holds cold better and cycles less.

Entertainment and electronics. A 32 to 43 inch LED TV draws 50 to 90W. A router and modem together draw 15 to 25W. A laptop charging draws 45 to 65W, a phone charger 5 to 10W.

Kitchen appliances. A microwave draws 800 to 1200W while actively cooking, but typically for short bursts rather than continuously. An electric kettle draws 1500 to 2000W, also briefly. A small coffee or espresso machine idles around 200 to 300W and spikes higher when brewing.

Cooling and heavy loads. A 1 ton inverter AC draws roughly 700 to 1000W in steady operation, a 1.5 ton unit 1000 to 1500W, and a 2 ton unit 1500 to 2200W, all considerably more during compressor startup. These are the loads most likely to force a larger battery bank than everything else on this list combined, so size them deliberately rather than by default.

Water and laundry. A 0.5 HP water pump draws roughly 370 to 450W while running. A washing machine varies enormously by cycle, roughly 300 to 500W on a wash cycle and considerably more if it has an electric heating element for hot water. An iron draws 1000 to 1800W, briefly and intermittently.

What to generally exclude from backup sizing. Electric water heaters or geysers, typically 1500 to 4500W, are usually excluded from a backup calculation entirely, since covering them requires a battery bank of a scale most households do not need for anything else. The same applies to central air conditioning or multiple simultaneous AC units unless you have specifically sized for that, which our 5kW system guide covers in depth.

Matching your result to an actual battery

Once you have a kWh figure, from the calculator or worked out by hand, translate it into a real product rather than stopping at the number.

For 24V systems: an itel 24V 100Ah pack holds about 2.56 kWh nominal, and an itel 24V 200Ah holds about 5.12 kWh.

For 48V systems: an itel 48V 100Ah pack holds about 5.12 kWh nominal, and an itel 48V 314Ah holds about 16.08 kWh.

Divide your required nominal kWh by the pack size to see roughly how many units you need, rounding up. Our itel range guide covers each of these in detail, and our comparison guide works through when several smaller packs beat one larger one, and vice versa.

What a calculator cannot tell you

Two things worth flagging, because a kWh figure alone does not finish the job.

It does not tell you your required discharge current. A battery with enough stored energy can still be the wrong battery if its continuous discharge rating cannot cover your simultaneous peak draw, particularly relevant if air conditioning or heavy motors are part of your load. Our 48V 100Ah guide explains why this figure matters as much as capacity.

It does not tell you whether your solar array can actually refill the bank you have just sized, particularly through winter when generation drops. A battery sized purely from evening consumption can still be the wrong battery if nothing can fill it by the next evening.

How many hours should you actually enter

This single input changes the result more than anything else in the calculator, and it is the one people guess at rather than check.

If your area has a published, fairly predictable load shedding schedule, use the length of a typical outage block from that schedule, not the shortest one and not the longest one you can remember. Your local electricity distribution company can usually confirm the current schedule for your feeder if you are unsure, and neighbours who have lived in the area for a while are often a faster source than any official channel.

If your outages are unpredictable rather than scheduled, faults, voltage fluctuation trips, or genuinely irregular supply, look at your last few months informally rather than sizing for a single worst night. A battery sized for the rare eight hour outage that happens twice a year, at the cost of being oversized for every other night, is usually the wrong trade. It is generally more sensible to size for your common case and accept that an exceptional outage may mean running a lighter load, using a generator as backup for that specific scenario, or simply going without air conditioning for one unusually long night.

Urban areas with relatively stable supply often do well sizing for 4 to 6 hours. Areas with heavier or more frequent load shedding, particularly some semi-urban and rural feeders, may need 8 hours or more to feel genuinely comfortable. There is no universally correct number, only the number that matches your actual experience.

Does the result feel right

A rough sanity check, useful whether you used the calculator or worked it out by hand.

A normal household evening of fans, lights, a fridge, a TV and general electronics, without air conditioning, typically lands between 3 and 5 kWh for a six hour period. If your result is well outside that range without an obvious reason like AC or a water pump in your selection, it is worth checking your inputs. Common overcounting mistakes include leaving the AC or water pump ticked when you did not mean to, entering an unrealistically high quantity for lighting, or setting the “use” fraction to 1 for something that only runs briefly, like an iron or a kettle.

Households adding one inverter air conditioner for three or four hours typically land between 7 and 10 kWh. Larger homes running two ACs or genuine overnight coverage often land at 15 kWh or beyond, which is where a single 48V 314Ah unit or several 48V 100Ah packs in parallel become the sensible answer rather than an oversized purchase. Our guide to how many batteries a 5kW inverter needs works through the series and parallel arithmetic once you have your kWh figure.