ebbillcalc

220 Ah battery backup time

How long a 12 V 220 Ah tubular inverter battery runs at different loads, alone and as a 24 V pair.

  • About 10 h 35 min at 200 W
  • About 4 h 40 min at 400 W

One 220 Ah battery (12 V inverter)

A fully charged, healthy battery. At 400 W it discharges at about 0.19C, against the C20 (0.05C) its Ah is rated at, so it gives less than the label.

LoadBackupExample
50 W42 h 10 minWi-Fi and two lights
100 W21 h 05 minA fan and three lights
150 W14 h 05 min
200 W10 h 35 minTwo fans, four lights, TV
250 W8 h 10 min
300 W6 h 35 minThree fans, lights, TV, Wi-Fi
400 W4 h 40 minThree fans, six lights, TV, Wi-Fi
500 W3 h 30 minAdd the fridge
600 W2 h 40 minFour fans, lights, TV, fridge
800 W1 h 40 minA big house, or a cooler

Two 220 Ah batteries (24 V inverter)

The usual set-up for 1.5 kVA and 2 kVA inverters.

LoadBackup (2 batteries, 24 V)
300 W14 h 05 min
400 W10 h 35 min
500 W8 h 10 min
600 W6 h 35 min
800 W4 h 40 min
1000 W3 h 30 min
1200 W2 h 40 min
1500 W1 h 55 min

220 Ah models we list

Specs as stated on each manufacturer’s page. Sorted by brand; we don’t rank them.

ModelTypeWarrantyMaker’s backup at 400 W
Exide FEM0-IMTT2300tall tubularNot stated—
Exide IZTT2200HLtall tubular60 months (36 free replacement + 24 pro-rata)4 h 45 min
Livguard IT2272TTtall tubular72 months (48 free replacement + 24 pro-rata)—
Luminous Inverlast ILTT 26060tubular60 months (36 free replacement + 24 pro-rata)—
Luminous Red Charge RC 26000 Protubular48 months (24 free replacement + 24 pro-rata)—
Microtek M2203624TTtall tubular60 months (36 free replacement + 24 pro-rata)—

Method: watt-hours at 12 V × the share lead-acid delivers at that current, fitted to V-Guard’s published 400 W backup table, ÷ load. Checked against Exide’s Inva Zen tables, which it matches within about 10% from 200 to 400 W and undershoots at 100 W. Real backup falls as the battery ages.