How to stop car battery drains?

Do you find your car battery dead quite often? If so, then your car may be experiencing the problem of battery drainage, leading to an exhausted battery. Most of the times unwanted battery drainage is caused due to prolonged switched on headlights, the radio system or the internal lights when the car is not running. Again, it may be your proximity keys which always keep scanning for radio signals or your music system in the stand by mode. Apart from these visible reasons, there are some minute facts which may cause your battery to drain away slowly. These may be untidiness of the battery, a leaked battery or inappropriateness of the wires used for the various electrical and electronic gadgets in your car. Here are some checkpoints which will help you to watch out for a car battery drain:

Car Battery Drain
Car Battery Drain

Difficulty level: Easy

Time required: It varies person to person.

Resources required

  1. A low range multi-meter (having milli ampere current measuring range)
  2. A screwdriver (you can use the one in your car's utility box)
  3. A rag (to clean the battery terminals, if found dirty)
Estimate cost: NA


  1. First of all, let us check if there is any minute battery drain in your car. Switch off and disconnect each and every electrical and electronic gadget in your car which makes use of the battery. These equipments are nothing but your radio, music system, internal lights, GPS system, proximity key sensor, etc. Thereafter, connect the meter in series by removing any fuse connected directly with the battery terminals. Alternately, you can also remove a battery terminal and connect the meter in series with the whole electrical circuitry of your car. Switch on the multimeter and put it in the ammeter mode within the range of 2 A or 200 mA. If you find about 10-20 mA reading in the meter, then this is the residual current drainage that is occurring from your battery.
  2. If your car is suffering from an abnormal battery drain, check your battery physically for dirt or loose connections. Both dirt and loose connection at the terminals may cause the battery to die down slowly. Loose connections generate heat, putting an extra load on the battery. If found, loose connections should be fixed properly to save the battery. Keep the battery and it's terminals clean using a rag or duster.
  3. Switch off all electrical gadgets and systems in your car when it is not running. When you need to leave your car in a parking lot for a week, make sure that no electrical component is running inside which may drain away your battery.
  4. Many speakers (usually the ones which are not the branded ones) come with wires with poor conductivity and more resistance. These causes more power loss causing your battery to die off. If the amplifiers fail to go to standby, the speakers stay powered for a long time exhausting the battery even if they are not producing any sound. Thus always use a music system manufactured by a good brand for your car.
Frequently asked questions1. Which devices mostly cause a car battery drain?

It is your proximity sensor key always scanning for radio signals or your massive sound system which hasn't switched over to the stand-by mode when your car is in the parking lot. It may also be your GPS receiver always tracking your position by communicating with the GPS satellites.

2. How frequently do I need to check my battery?

Well, you should go for a scheduled car battery checkup once in every 2-3 months. Physically examine the battery and replace it if any major problem is found.

Quick tips:

  1. Don't forget to turn off the internal lights or dim lights when you park your car.
  2. Switch over the audio systems to the stand by mode when not in use.
  3. Unplug any unused mobile or laptop charger plug as it drains your battery even if they are not charging anything, when connected to the mains.
  4. If your car battery is still dying away despite following the above steps, better visit a good technician and have it inspected.
Things to watch out for:
  1. Always look out for short circuited terminals. Your d.c. battery will produce sparks if the terminals get shorted by any means or gets touched with the ground circuit.
  2. While checking your battery's current drain with a meter, do not do any stupid things like switching on your headlight or blowing the horn as it will draw a large amount of current from the battery, thus blowing off the fuse of the meter (as the meter will then be in a low ampere range).
  3. Always have the maintenance manual of your vehicle by your hand and strictly follow the instructions therein to open the battery cover or dismantle the battery.

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