Trickle Charge Dead Car Battery

Most car batteries can last as long as 5 years without a recharge or replacement. While this is true, they eventually run out of power. At times, car batteries lose charge prematurely especially when you leave the lights on for long.  Finding yourself with a dead car battery is a serious inconvenience. Luckily, you can easily recharge your car battery. You just need very little mechanical know-how and a speed/trickle charger to do so.

Preparing To Charge Dead Car Battery

First thing first, wear the right safety gear. More so, ensure you are working on a well lit and ventilated area.
Second, check the type of car battery you have. This is always written on the battery. If the label is missing or too worn out, then visit the manufacturer’s site for details.  No the same note, check the battery’s voltage on the label or your car’s manual. If you have a wet cell battery, then you can easily service it. This implies that there are steps you can follow to improve its life and charge it. Alternatively, VRLA car batteries do not need maintenance and are completely sealed.

Before charging battery, do this:

Check out the physical appearance of the car battery. It should not be leaking battery acid and should be in place without cracks.
If it has either of those signs, do not proceed.  Another thing is to confirm that the cables connected to the battery are free of corrosion and secure. If there are signs of corrosion, use a brush with firm bristles to clean.

How To Recharge A Car Battery Using A Trickle Or Speed Charger

Step 1

Put the battery charger on a firm surface, but not on the battery itself. Place it at a distance depending on how long the charger cables are.  Use the entire cable length to separate the charger from the battery as much as possible.

Step 2

Connect the speed/trickle charger to the car battery. Connect the black cable from your charger (has a negative sign on it) to the negative terminal of the dead battery.
Likewise, connect the red-cable (with a + sign) to the positive terminal of the battery. Mixing the negative and positive terminals might damage the battery.

Step 3

Set the right speed on the charger. Digital chargers normally show the current voltage in a car battery. As such, you will be able to set your final voltage level. Ensure you set the same voltage as the one on the manufacturer’s manual.  Other older chargers will simply come with on and off settings. 
On the same note, speed chargers will let you select the speed for charging the car battery. Fast speed is ideal for a battery that has recently run out of charge because you left the lights on or something similar.  Nevertheless, do not fast charge the battery if you will leave the car unattended. As for the slow charge, it is ideal for a battery that has been dead for a long time. Luckily, you can leave the car battery on slow charge even the entire night.

Step 4

Check whether the car battery works after charging. Using a digital charger is better than the older version. A digital charger will give a read-out. This indicates whether the battery is holding the charge properly. In like manner, it will tell you whether the battery will require a replacement.


If the car fails to start even after charging the battery, you should let an expert check it. So, remove the car battery (if you have not done so already) and take it to an auto parts store. There, the mechanics will check whether the battery needs a replacement, can be serviced or if they can charge it. If the car battery is really bad, then you should buy another one. Alternatively, you might have fully charged the battery but still, the vehicle won’t start. In this case, then the cables need to be checked. Maybe the cables are not connecting firmly to the car battery or are broken.

For complete understanding of basics of batteries, check out our related articles.

You might also want to look at article of 7Ah battery charger using microcontroller.

For any help you can contact us or comment below for feedback. Like our Facebook page to stay tuned with us

What do you think?

This site uses Akismet to reduce spam. Learn how your comment data is processed.