Car Battery Keeps Going Flat: Causes
A battery that keeps going flat usually isn’t just “a bad battery”. A Cranbourne West specialist explains.
What it usually means
Repeated flat batteries usually point to one of three things: an ageing battery that won’t hold charge, a charging fault (the alternator not recharging it properly), or a parasitic drain — something staying on after you lock the car (a light, module or aftermarket accessory) and slowly draining it overnight.
Short trips that never fully recharge the battery can also be the cause.
What you should do
Get all three tested rather than just replacing the battery — fitting a new battery won’t fix a charging fault or a drain.
We load-test the battery, test the alternator output, and measure for a parasitic drain to find the actual cause.
How we find & fix it
Because the same symptom can have several causes, we use dealer-level diagnostics and a methodical check to pinpoint the real cause — rather than throwing parts at it.
You get a clear explanation and a fixed written quote before any work. Book online in 60 seconds or call 03 8782 0711.
Car Battery Keeps Going Flat: Causes — FAQ
Usually an ageing battery, a charging (alternator) fault, or a parasitic drain — something staying on after lock-up.
Not if it’s a charging fault or a drain — we test all three first.
Something staying powered after you lock the car (a light, module or accessory) that slowly flattens the battery.
We load-test the battery, test the alternator, and measure for a drain.
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Car doing something odd?
Trusted Cranbourne West car specialists — RACV-accredited, fixed written pricing. Book online or call 03 8782 0711.