CAUTION: use eye protection
CAUTION: attach cable leads to battery according to manufacture specs before turning on charger
CAUTION: possible explosive gasses can be present, beware the rotten egg smell
Yes, there is a wrong way to charge your battery. The absolute worst thing you can do, is jump start the car, then drive it, to let the alternator charge it back up. This almost always ends up in a double disaster. Not only is the battery poorly charged, but you’re lucky if the alternator still works. You must have a battery charger to charge a battery without causing some sort of damage elsewhere.
Now that we’ve established that, let’s talk about how to properly use your battery charger. You’ll notice most chargers have an amp meter and an amperage select switch. Here’s the 3 things you need to know.
1. The ammeter tells you how much juice is going into the battery. Usually this will self regulate. In other words, if the charger and battery are working properly, when you hook the charger to a low battery, set the selector switch to a medium rate (20amps for example) the ammeter will read around 20 amps.
2. Then, as you wait on the battery to charge, the ammeter should be moving toward zero. It is the general consensus that as the battery charges, the charger reduces the rate that it charges. Some chargers will even shut themselves off when the charging cycle you have selected is complete.
3. This is a sign that the battery is good, and if you don’t notice this happening, it’s a sign of the battery being bad. This is a condition that some batteries have, when they won’t take a charge. A battery that won’t charge up is to be considered unusable.
However, the higher amps rate you charge your battery at, the less efficient the job gets done. Sure, it gets done faster… but not properly. The best way to charge a battery is to trickle charge. This takes all day, but it does a way better job.
When you charge a battery, think of washing your car. First you put the soap in the bucket. Then, you turn on the hose full blast, to try and fill up the bucket. When the suds clear away, you’ve only got a quarter bucket of water. Now you have to start all over again. It’ll probably take you about three times to get a full bucket of water. All you had to do, is turn the water on slowly and be patient.
Same thing with your battery. If you shoot a lot of amps into it right off the bat, all you get is a surface charge that will soon dissipate. But if you trickle charge, the amps sink deep into the cells completely restoring the amp hours to the manufacturers original specification