How to avoid getting a flat car battery

Posted on 18 Feb 2014 by Battery Business Team in Cars

battery business, flat car battery

We all want to avoid getting a flat car battery but... if your car engine is slow to start you’ve almost left it just a bit too late.

Get your battery checked quickly, before it goes the inevitable next step and refuses to start...

... that ominous, slow, churning noise or a solitary click from the engine bay when you turn the key.

Why Lead Acid Batteries Fail

Lead acid batteries fail, over time, as the acid eats away the insides and either causes the separator layers to fail, or causes sediment to short out between 2 cells, or something breaks (usually due to corrosion), or the sulphur in the sulphuric acid coats the plates and causes too much resistance (a process called sulfation). It’s not nice inside a battery full of acid, day after day!

Understanding Voltage Readings

If your car battery is giving out about 12.5 volts or more, but the car is slow to start, sulfation is likely to be the cause. Sulfation happens when the battery is below full charge, and it wrecks batteries after a relatively short period.

If you’ve had a battery in your garage for months without keeping it charged, it will (not might) be beyond redemption. If your car battery has been flat for a day or two, it’ll benefit from a charge on a charger that has a specific desulfation cycle.

If your car battery is showing somewhere between 10 volts and 11.2 volts, the chances are that 2 of the cells have shorted due to sediment or failure of the plate separator, so you now have 5 of the 2 volt cells, instead of 6.

A battery in this condition is also suitable only for recycling. It cannot be salvaged (once upon a time, the acid would have been flushed out, along with any sediment, and the battery refilled with fresh acid, but nowadays that can only be done at a licensed centre, where the battery will be stripped and 97% of the component parts will be recycled by melting, cleaning, purification and remoulding, into new batteries).

There is a slight chance that the battery is slightly discharged but…

…if your car battery is reading below 10 volts, it is probably because something is draining it.

Have you left a door open, or an interior light on, or has the CD player been scrambling for grip on the surface of a pirate CD and trying to eject it for hours on end (yes – really – it happens)?

As long as you find out quickly enough (within a few days) the battery can usually be recharged and saved. If it has dropped to less than about 3 volts, though, most battery chargers won’t know there is a battery there and won’t start charging. Give us a ring on 02 9970 6996 and we’ll try and help.

Battery Business Warranties

Oh, and when it comes to warranties, we typically provide a 3 year warranty on car batteries that we install. That warranty provides for your full legal rights in the event of battery failure due to manufacturing fault or defect, or goods being not fit for purpose.

It doesn’t cover batteries that have been submerged, dropped and cracked, shorted-out by a dropped spanner, smashed in a collision, drilled-through, drained by an interior light left on whilst you were on holiday etc (but believe me, we’ve had examples of all the above presented to us – sometimes with the battery being a brand we’ve never even sold).

The good news, though, is that if it isn’t a warranty, there’s a fair chance that we can save the car battery unless it is just very old and tired.

There's no point in waiting till you've got a flat car battery. We test batteries for free, 7 days a week, no appointment required. If your car is slow to start, we’ll tell you why, and you’ll often get a free coffee while you wait!