Sizing Lithium Battery Storage for a Kenyan Home or Shop

The question people bring to the counter is rarely "which battery is best". It is "how many kilowatt hours do I actually need". That is the right question, and you can answer it yourself in about ten minutes with your last Kenya Power bill and the labels on your appliances. Here is how, using the batteries we stock rather than a generic example.

A kilowatt hour is a bucket, not a rate

A kilowatt hour (kWh) is one kilowatt drawn for one hour. A 2,000 W kettle boiling for six minutes uses 0.2 kWh. Eight 9 W LED bulbs burning for five hours use about 0.36 kWh. It is a quantity of energy, like litres in a tank.

That distinction matters because batteries are sold in kWh while appliances are labelled in watts. To move between them: watts x hours, divided by 1,000, gives kWh.

Your bill carries the whole-house answer already. One unit is one kWh, so divide the monthly units by 30 for a daily average. A battery only has to carry the evening and overnight share of that, plus whatever an outage takes out of your day.

Read the label: volts times amp hours

Datasheets quote voltage and amp hours. Multiply them for watt hours:

• 51.2 V x 100 Ah = 5,120 Wh, so 5.12 kWh
• 25.6 V x 280 Ah = 7,168 Wh, so 7.16 kWh
• 48 V x 200 Ah = 9,600 Wh, so 9.6 kWh
• 51.2 V x 314 Ah = 16,077 Wh, so 16.07 kWh

Those are the four lithium iron phosphate (LiFePO4) units in our Battery Storage range. Note that amp hours alone tell you nothing: the 280 Ah unit stores less energy than the 200 Ah Dyness, because it runs at roughly half the voltage.

Battery prices in our catalogue are listed as price on request, so ask at the counter for the current figure. Send us your load list and we will price battery, inverter and panels as one job.

What 5.12 kWh runs through an outage

The LVTOPSUN 5.12kWh Power Wall is where most homes start. Work out an evening with a simple table. These are typical draws: read the plate on your own appliances, because they vary.

That sits just below the range our Dyness listing quotes: a typical Kenyan home on lights, a fridge, TV, Wi-Fi and charging uses roughly 3 to 5 kWh overnight. So 5.12 kWh carries a night with reserve, on one condition: the kettle, iron, microwave and instant shower heater stay off the backup circuit.

Those four are what empty a small bank. An iron at 1,500 W for twenty minutes is 0.5 kWh; a 4,500 W instant shower for ten minutes is 0.75 kWh. Two showers and one ironing session come to 2 kWh, close to two fifths of the battery, before the fridge has done its night's work.

What 16.07 kWh runs

The LVTOPSUN 16.07kWh Power Wall is roughly three times the entry wall, which changes what you can leave connected. The house above could run its full overnight load, iron and shower included, and still hold reserve for a second evening.

It is also the size that starts to make sense on a farm or in a shop. A 1 HP borehole pump at 0.75 kW running two hours is 1.5 kWh. Pond aeration overnight, or a chest freezer in a duka, are steady loads a 5 kWh wall will not comfortably absorb alongside the house. If a pump is the reason you are buying, send us its rating and daily hours before you order.

kWh is the tank. kW is the tap

Energy is only half the specification. The 5.12 kWh wall is rated at 100 A discharge current and 5,120 W discharge power. That is what it can deliver at any one instant. A 2,000 W kettle and a 1,500 W iron together draw 3.5 kW, which fits. Add a 4,500 W shower heater and you are past the limit, however much energy is left in the battery.

So write down two numbers: total energy over the night, in kWh, and worst simultaneous draw, in kW. Size the battery on the first and the inverter on the second.

Charging works the same way. That unit charges at 50 A, 2,560 W, so a full recharge from empty takes roughly two hours if the supply can push that hard. The Solar Inverter 6KW + 5.12KW Btter Y+ 5SOLAR Panels of 625WATTS package bundles a 6 kW inverter, 5.12 kWh of storage and five 625 W panels: an array of 3,125 W on paper. In strong midday sun that is enough to push charging at close to its rated rate. Under cloud, or early and late in the day, it falls well short.

Depth of discharge: size on usable energy

Depth of discharge is the share of the nominal capacity you actually take out. A lead-acid bank is conventionally worked to about half its rating, so a 10 kWh lead-acid bank is really a 5 kWh bank. LiFePO4 tolerates much deeper discharge, which is why a lithium wall does more work than a lead-acid bank of the same headline size.

We do not publish a depth-of-discharge figure for these units, so ask us for the datasheet on the batch in stock and size on usable kWh rather than the number on the box. As a planning habit, leave headroom: at 90 per cent you would treat 5.12 kWh as roughly 4.6 kWh and 16.07 kWh as roughly 14.5 kWh.

Cycle life and what it costs per night

The Dyness Powerboxpro 9.6kWh Battery is rated at more than 6,000 charge cycles, with 5 and 10 year warranty options. Cycled once a day, 6,000 cycles is over sixteen years of service.

That is the number to divide the counter price by. Cost per cycle, rather than price per kWh, tells you whether two batteries at similar money are the same purchase. Cycle ratings are not quoted for the LVTOPSUN walls in our catalogue, so ask us before you compare.

The Dyness is also sealed to IP65, so it can go in a utility room, garage or sheltered outdoor wall. LiFePO4 does not vent gas the way lead-acid does, so none of these need a vented battery room, only a dry, ventilated space. At the coast, keep any outdoor mount well sheltered from salt air.

Hybrid or off-grid

The Dyness listing states both: off-grid and hybrid.

Hybrid means you keep the Kenya Power meter. The battery covers outages and shifts daytime solar into the evening. You are sizing for one bad night plus a margin, so 5.12 kWh or 7.16 kWh is usually enough, and the grid recharges you if the sun does not.

Off-grid means the battery is the only thing between you and darkness at eight in the evening. Size for the worst week, not the average: during the long rains, yield drops for days at a stretch. That points to the larger banks, 9.6 kWh or 16.07 kWh, and more panel than sunny-day arithmetic suggests.

If you already run a 24 V inverter, the LVTOPSUN LVTS-256280 7.16kWh Power Wall at 25.6 V lets you upgrade storage without replacing the inverter. And the Dyness quotes an output range of 10 to 20 kWh because units can be paralleled, so you can start with one and add later.

When lighting is the whole job

If all you need is a lit compound or gate, storage on this scale is over-specified. The 100W Solar Floodlight · Light + Panel, and its 200 W and 300 W versions, are self-contained and stay on for 10 to 15 hours on a day's charge. For an outbuilding or a shamba house, the 30W Solar Panel +BATTERY+3 Bulbs kit covers lighting on its own, without a storage system behind it. Both sit under Solar Lighting & Power.

What to do next

1. Take your last three Kenya Power bills and work out your daily units.
2. List what must stay on in an outage. Multiply watts by hours for each and add them up. That is your kWh.
3. Add the worst case: everything that could run at the same moment, in kW. That sizes the inverter.
4. Decide hybrid or off-grid, because off-grid needs the bigger bank.
5. Bring both numbers to us and we will match battery, inverter and panels.

Come to the Nairobi counter at Darosa Plaza, Ground Floor, Karen Road, or the Mombasa counter opposite Ratna Square. The full range is at Solar & Power.