Calculate parasitic battery drain from keep-alive circuits and estimate how long before the battery is too depleted to start.
Input Parameters
Results
--
Days to Flat
days
--
Daily Ah Drain
Ah
--
Annual Energy Cost
Wh
--
Draw Status
Note: Normal parasitic draw is 20-50 mA for modern vehicles. Pull fuses one at a time to isolate excessive draw. Wait 30-60 minutes for modules to sleep before testing.
Reference
Effective Ah = Capacity × (1 − 0.05 × Age)
Usable Ah = Effective × 50% (min charge for start)
Hours to Flat = Usable Ah / (Draw_mA / 1000)
Days to Flat = Hours / 24
Normal draw: under 50 mA