UPS Battery Life Estimator

Estimate remaining UPS battery capacity and predict replacement date. VRLA battery life halves per 15 deg F above 77 deg F.

VRLA (5 or 10 year design life) or Li-ion (10-15 year, less temp sensitive).
Time since installation. Replace VRLA at 80% of design life (best practice).
years
Average battery room temperature. VRLA rated at 77F (25C). Life halves per 15F above 77F.
F
Number of discharge events. VRLA rated ~300 deep cycles. Li-ion ~3,000 cycles.
cycles
Typical discharge depth per cycle. 20% (short outage) vs 80% (full runtime).Deeper = more wear.
%

Results

Nominal Design Life:
Manufacturer rated life under ideal conditions.
-years
Temperature-Adjusted Life:
Actual expected life adjusted for operating temperature.
-years
Cycle Wear Impact:
Percentage of cycle life consumed.
-%
Estimated Remaining Capacity:
Current capacity estimate. Replace at 80% per IEEE 1188.
-%
Estimated Remaining Life:
Time until capacity drops below 80%.
-years
Recommended Replacement:
Projected replacement date.
-
Status:
Current battery health status.
-
Reference: IEEE 1188 (VRLA), IEEE 1189 (Li-ion). Arrhenius equation: VRLA life halves per 15F above 77F. Replace at 80% capacity. VRLA ~300 deep cycles; Li-ion ~3,000.