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230 Ah battery backup time

How long a 12 V 230 Ah tubular inverter battery runs at different loads, alone and as a 24 V pair.

  • About 11 h at 200 W
  • About 4 h 55 min at 400 W

One 230 Ah battery (12 V inverter)

A fully charged, healthy battery. At 400 W it discharges at about 0.18C, against the C20 (0.05C) its Ah is rated at, so it gives less than the label.

LoadBackupExample
50 W44 h 10 minWi-Fi and two lights
100 W22 h 05 minA fan and three lights
150 W14 h 40 min
200 W11 hTwo fans, four lights, TV
250 W8 h 35 min
300 W7 hThree fans, lights, TV, Wi-Fi
400 W4 h 55 minThree fans, six lights, TV, Wi-Fi
500 W3 h 40 minAdd the fridge
600 W2 h 55 minFour fans, lights, TV, fridge
800 W1 h 50 minA big house, or a cooler

Two 230 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 40 min
400 W11 h
500 W8 h 35 min
600 W7 h
800 W4 h 55 min
1000 W3 h 40 min
1200 W2 h 55 min
1500 W2 h

230 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
Amaron AM230TT54tall tubular54 months (36 free replacement + 18 pro-rata)—
V-Guard VT 250Not statedSee V-Guard’s product page (it differs from the 2021 brochure)5 h

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.