Battery Chargers

Choosing a good battery charger

If you are thinking of purchasing an auxiliary battery charger to charge your battery bank from a generator or the grid, there are a few things you should take into consideration before making your purchase. One of the first things you should look at is if the charger can sense the state-of-charge of the battery and if it can perform multi-stage charging. With a multi-stage charger your batteries will be charged efficiently without being overcharged. Choosing a cheap battery charger can take years of service out of your battery bank, which then can be costly if you need to purchase new batteries prematurely

Features of a Quality Charger:

* Automatic tapering as batteries reaches full charge
* Drops to a lower charge to “float” the batteries
* Full rated current during bulk charge
* Adjustable output voltage for different applications
* Manual or automatic equalization cycle
* Temperature compensated charger voltage

Multi-Stage Charger

Stage 1: Bulk- this is where the most amperage is applied to the batteries
Stage 2: Absorption- the charger now senses the battery is close to 100% so the amperage is lowered.
Stage 3: Float- the battery is now 100%. Charge current is lowered to a few amps and “floats” the batteries

A good battery charger senses the battery voltage and gradually reduces the output current as the voltage rises. This will greatly reduce the probability of overcharging, which is critical to battery life and safety. A battery that is being overcharged will have its electrolyte boiled way and once the cell plates become exposed, the battery will either be completely destroyed or badly damaged. Choosing a proper charger will pay-off immediately, but even more so in the long run.

Proper Battery Ventilation

Batteries, when being charged create a highly flammable gas known as hydrogen. This gas, if not vented out of the battery area, can have dire consequences if ignited. If a good charger is used, this gassing will be keep to a minimum; however,this small concentration (~2%) can still cause an explosion. OVERCHARGING will greatly increase this concentration . The best place to locate a vent to rid the battery room of hydrogen is above the batteries leading to fresh air outside. The reason you want to place a vent over top the batteries, is because the hydrogen gas is less dense (lighter) than air we breathe, so it will rise to the top of the battery room. Never carry ignitions sources near your batteries because an explosive reaction is possible.