Battery Chargers
Some of our cars spend more time on the battery charger than they do on the pavement. A lot of us seem to have more battery chargers than we have batteries. You want a battery charger that collects information from the battery and adjusts the charge current and voltage based on this information. You also want a charger that can remain connected to the battery indefinitely and will not overcharge or damage the battery. Those are the basics.
What type of battery or batteries you will be charging? Is it maintenance free, a wet cell (flooded), an AGM (absorbed glass mat) or a gel cell? In most cases one of the newer chargers will work for all types.
If you want to know the time it takes to charge your battery simply find the amp hour rating of the battery and divide by the charger rating (amps). Then add about 10% for the extra time to totally top off the battery. Having said that I need to add that some of the new chargers use a very sophisticated algorithm that can charge with two times the amp output.
The number of amps has a real bearing on the price you’ll pay for a battery charger. You can spend less than $50.00 for a charger that has fewer than 4 amps. If you feel you need 10 amps plan on spending around $100.00 for your charger. Remember though that more amps will simply allow you to charge the battery faster – not better.
If you put too many amps into your battery too quickly you can damage your battery and in the case of sealed or maintenance-free batteries that damage can be irreversible.
Some of the trickle chargers don’t have the advantage of sophisticated electronic controls. As they allow the value of the charging current to trickle down to what appears to be safe levels the output voltage of the charger actually rises well above 15 volts DC, sometimes even going higher than 16 volts. This voltage is well above the gassing voltage of a lead acid battery and some battery manufacturers will void your warranty for using chargers with voltage ranges outside the manufacturer's specifications. If the battery remains connected to this high level of voltage for an extended period of time, even less than a single day, you might very well damage your battery.
Solar chargers are generally designed to work through your car’s cigarette lighter. You probably don’t have one of those in your racecar. While solar battery chargers may be good for maintaining and extending the life of battery they’re not much good if you have a dead battery. Some of the less expensive solar units may not be properly regulated which can lead to overcharging We may be a couple of years away from using solar batter chargers in the paddock.
Optima has found that a lot of the batteries returned under warranty are not actually defective. Too often they’re just deeply discharged. The problem for many battery owners is that older, analog-style chargers won’t charge a battery that’s been discharged below a minimum voltage threshold. In some cases this threshold can be as high as 10.5 volts.
These chargers can successfully recover deeply discharged batteries only if a second, fully charged battery is wired in parallel to the deeply discharged battery. The voltage in the fully charged battery will allow the charger to turn on and deliver current to the deeply discharged battery. Once that battery is recharged above 10.5 volts, the discharged battery can be connected directly to the charger for the remainder of the charging cycle.
