The Ah you need depends on two things: the total watts you want to run and the number of hours you want them to run. As a starting point, Okaya suggests a 160Ah battery for a 2BHK home, 90Ah for compact needs and 210Ah or more for larger homes and longer backup. This guide shows how to calculate the figure yourself and how Okaya's Certified Backup Hours help you confirm it before you choose a battery for inverter use.
Ah stands for ampere-hour. It is the battery's rated charge capacity, and a higher Ah rating means the battery can store more energy and run your appliances for longer.
Multiply the Ah by the battery voltage to get the stored energy in watt-hours (Wh). For example, a 12V, 160Ah battery holds about 1920 Wh (12 x 160). Backup hours then depend on how many watts you draw from that energy.
Multiply your total load in watts by the backup hours you want, then divide by the battery system voltage. This gives the minimum Ah, and a real battery needs more than this figure.
Step 1: List the appliances you want to run during a power cut and note the watts of each from its label.
Step 2: Add them up to get the total load in watts.
Step 3: Decide the backup hours you need, based on how long power cuts last in your area.
Step 4: Multiply watts by hours to get watt-hours, then divide by the system voltage (12V or 24V).
Okaya's inverter power calculator does the first two steps for you, and the guide on how to choose the right inverter VA for your home shows how to check that the inverter itself can carry the same load.
Worked example: a 500 W load for 5 hours needs 2500 Wh. On a 12V system, 2500 divided by 12 is about 208Ah. This is only the starting point, because an inverter loses some energy in conversion and a lead-acid battery is not drained fully. The real requirement is therefore higher, and Okaya's CBH table below shows by how much.
Okaya publishes Certified Backup Hours (CBH) for its inverter batteries at specific test loads. For 90Ah to 260Ah models, the published figures cover 400 W, 300 W, 200 W and 100 W loads, while the 310Ah model is declared at 600 W, 500 W, 400 W and 300 W. Each battery is tested under the UMHD (Urban Metro Heavy Duty) load cycle by NABL-accredited third-party labs, and the CBH value is printed on the packaging. You can read the method on the Certified Backup Hours (CBH) table page.
|
Series |
Capacity (Ah) |
Container |
Warranty (months) |
400 W |
300 W |
200 W |
100 W |
|
PowerOn |
90 |
JXT |
48 (24+24) |
1:15 |
1:45 |
3:25 |
8:10 |
|
PowerOn |
110 |
SJT |
48 (24+24) |
1:45 |
2:45 |
4:55 |
11:30 |
|
PowerOn |
140 |
SJT |
48 (24+24) |
2:30 |
3:50 |
6:35 |
15:05 |
|
PowerOn |
160 |
SJT |
48 (24+24) |
3:00 |
4:30 |
7:50 |
17:20 |
|
PROPower |
160 |
SJT |
60 (36+24) |
3:05 |
4:40 |
8:00 |
18:40 |
|
PROPower |
160 |
TT |
54 (30+24) |
2:55 |
4:25 |
7:45 |
18:30 |
|
PROPower |
160 |
TT |
60 (36+24) |
3:15 |
5:05 |
8:45 |
20:15 |
|
PROPower |
190 |
TT |
60 (36+24) |
4:20 |
6:25 |
10:35 |
23:30 |
|
PowerOn |
210 |
TT |
48 (24+24) |
4:30 |
6:40 |
11:25 |
24:50 |
|
PROPower |
210 |
TT |
60 (36+24) |
4:40 |
7:10 |
12:05 |
28:10 |
|
PROPower |
230 |
TT |
60 (36+24) |
5:30 |
8:00 |
13:20 |
29:30 |
|
PROPower+ |
260 |
TT |
66 (42+24) |
6:15 |
9:15 |
15:05 |
32:40 |
|
PROPower |
310 |
TT |
60 (36+24) |
3:45 |
5:10 |
6:40 |
9:45 |
Compare this with the worked example above: for 500 W, Okaya lists 5 hours 10 minutes for the 310Ah battery, so a 500 W load for 5 hours needs a battery in that class. A rough 200Ah estimate would run short.
Okaya's guidance is to match the Ah to the size of the home and the load you run. Check the Certified Backup Hours listed above against your own load, and use home inverter battery capacity listings to compare the available ratings. The BHK-wise power backup guide explains typical loads by home size.
1. 90Ah: compact needs.
2. 160Ah: 2BHK homes.
3. 210Ah: larger homes or longer backup.
4. 260Ah: homes with heavy loads.
5. 310Ah: commercial or heavy-duty use.
Okaya's current inverter battery range has nine capacities: 90Ah, 110Ah, 140Ah, 160Ah, 190Ah, 210Ah, 230Ah, 260Ah and 310Ah, with warranties from 48 to 66 months.
If you are replacing an older battery, note that Okaya has upgraded 100Ah to 110Ah, 150Ah to 160Ah and 200Ah to 210Ah. Look for Upgrade From 100Ah To 110Ah, Upgrade From 150Ah To 160Ah and Upgrade From 200Ah To 210Ah on the product pages when choosing a replacement.
The battery voltage must match the inverter system voltage (12V or 24V), while the Ah can be chosen to suit your backup hours. A 24V inverter uses two 12V batteries connected in series. Always check the inverter manual or ask Okaya Care for the recommended battery capacity range, and read why compatibility matters in power backup systems before you pair them.
Tubular batteries are built for repeated charge and discharge cycles, which is what a home inverter battery goes through. Okaya's range uses Super Jumbo Tubular (SJT) and Tall Tubular (TT) designs with Advanced Tubular Technology, and each battery has a spill-free crown cover with six water level indicators. Browse Okaya's tubular inverter battery range or read which inverter battery is best for home for a comparison by use case.
Backup time falls as the connected load rises, so adding an appliance during a power cut shortens it. Battery age, charge level at the time the power goes and water level in the cells also affect what you get in practice.
For a deeper look at capacity selection, the choosing the right inverter battery capacity guide covers capacity trade-offs in more detail.
How much Ah inverter battery is required for a home?
It depends on your load and backup hours. Okaya suggests 160Ah for a 2BHK home, 90Ah for compact needs, 210Ah for larger homes or longer backup, 260Ah for heavy loads and 310Ah for commercial or heavy-duty use.
What is Ah in an inverter battery?
Ah means ampere-hour, the battery's rated charge capacity. Multiplying Ah by the battery voltage gives the stored energy in watt-hours.
How do I calculate the battery capacity for my inverter?
Multiply the total watts of your appliances by the backup hours you want, divide by the system voltage, and choose a battery above that figure to allow for conversion losses. Okaya's CBH table gives certified hours at set loads to cross-check the result.
How many hours of backup does a 160Ah battery give?
For the 60-month tall tubular 160Ah model, Okaya's CBH is 3 hours 15 minutes at 400 W, 5 hours 5 minutes at 300 W, 8 hours 45 minutes at 200 W and 20 hours 15 minutes at 100 W. The other 160Ah models are listed in the CBH table.
How many hours of backup does a 210Ah battery give?
For the 60-month 210Ah model, the CBH is 4 hours 40 minutes at 400 W, 7 hours 10 minutes at 300 W, 12 hours 5 minutes at 200 W and 28 hours 10 minutes at 100 W.
Is a higher Ah battery always better?
A higher Ah gives longer backup at the same load, but it should match your needs and your inverter's recommended range. Check compatibility before buying a much larger battery.
How many batteries does a 24V inverter need?
A 24V inverter uses two 12V batteries connected in series. A 12V inverter uses one battery.
Does Okaya still offer 100Ah, 150Ah and 200Ah batteries?
These have been upgraded to 110Ah, 160Ah and 210Ah in the current range.
Which Okaya battery suits a 2BHK home?
Okaya's guidance is the 160Ah battery for 2BHK homes. Confirm it against your own load using the CBH table.
What warranty do Okaya inverter batteries have?
Warranty ranges from 48 to 66 months depending on the model, shown as flat plus pro-rata months.
Compare ratings and current prices on the Okaya shop, or use the Okaya dealer locator to find an inverter battery dealer near you.
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