Must I Buy a 12 Volt Battery Charger?
photo credit: Charles Williams
Most likely the answer is yes. The battery charger is considered to be the most important factors in the life of a battery. In fact, using the right battery charger is so important that some manufacturers of batteries will not honor warranties if the proper charger is not used. At one time you had to be mindful not to overcharge your car battery. However with the introduction of the 12 volt battery charger back in the 1950s, things have really changed. Today, a lot of Marine or Power Sports batteries require a 12 volt battery charger to operate. Furthermore the high efficiency in today’s lead acid battery types require that they be charged more efficiently and using certain charging methods.
A battery is made up of individual “cells” that only have around 1.5 volts each as need to be connected together in series to build up a useable voltage. Most battery chargers use a microcontroller to monitor the amount of current flowing to the battery’s cells. If a battery shows a certain charge voltage, it will stop fully charging. This is to ensure that overcharging does not take place while also maintaining the right, small current, trickle charging. The wide range of uses for batteries also means that a 12 volt battery charger will have unique adjustable features that allow it to be used either for a 12v gel cell or a 12v solar cell. So, how do you pick the right 12 volt battery charger? It is the type of battery. In most cases, one charger will work for all. However, some chargers are known to work better for certain chemical cell types. You want to follow manufacturer recommendations to ensure your battery lasts a long time. A quality 12 volt battery charger is not cheap, but the same can be said of the batteries as well. Nevertheless, when used correctly, they can double or triple the life of your battery.
Another important consideration is the energy store of the battery. This is rated using the term Ampere-hours. This is the total amount of energy the battery is able to store. A typical auto battery has about 50 amp hours and would take 10-amp hour 12 volt battery charger approximately 6 hours to recharge it to full capacity assuming the battery was completely dead. A Marine Deep Cycle Battery is rated at 100 amp hours and would thus take a 10-amp hour charger 11 hours to charge to full capacity a discharged cell. Here is a rule of thumb to calculate the charge time. Take the amp hour battery rating, divide it by the charger rating and then add 10 percent. Another consideration to take note of is the desired use of the battery output. If you are going on use the charger on a trolling motor battery, then a fast and powerful charger will do the trick while a low current charger will work fine for batteries that will be used off season e.g. in a classic car or a motorcycle or an aircraft.