What is the hoopla concerning charging my batteries and these "STAGES"?
I thought the battery could only sit on one stage at a time?
(:- physicists trying to do electronics -:)
2-Stage and 3-Stage charging algorithms refer to the number of different steps in a charging routine. A 3 stage charger has 3 steps to charging a battery all the way up, and a 2 stage charger only has 2 steps. These steps are important as they dictate how the battery fills up with power. As one would guess, a three stage charger can fill a battery up just a bit better than a two stage charger, but it can also mess up a battery. THE LESSON: KNOW THE DIFFERENCE!
Generally there are three types of charging routines for batteries:
· 1 Stage Charge Controllers or Battery Voltage Regulators offer continuous rate charging. Without a charge controller, a solar panel is a great example of an unregulated or 1 stage power supply to the battery. Any type of power, simply hooked up to the battery in an uncontrolled manner, qualifies as a 1 stage charge. There is only one problem with this arrangement, it involves over charging your batteries, and it is inevitable. If your panels have enough power to charge the battery, they have enough power to "COOK" it as well. Just like when you put brownies in the oven too long, they burn after the moisture leaves, batteries do too. So Constant Current and Constant Amperage chargers are very dangerous to your investment in batteries.
· 2 Stage Charge Controllers -
There are 2 steps in a 2 Stage Charge Controller, the first is the Bulk Stage of the charge, the second is the Float Stage of the charge. These charge controllers are the best to use for applications where the load is always on (ie: refrigerator). The reason these charge regimen are best for batteries always under load is that they can not be "TRICKED" into over charging the batteries like a 3 stage charger, and something is "WATCHING" the charge, unlike the single stage charge above. The only drawback to a 2 stage charger regimen is the inability to fully charge the battery quickly. The bulk phase of the charge fills the battery up to roughly 90% capacity very quickly. Then the charge controller flips over to the float voltage. This voltage is very close to that of the fully charged battery. This is similar to hooking up a hose to a tank, but the pressure in the hose and tank are the same. The water doesn't move much, but evaporation is replaced as it happens. This is the drawback, the float voltage will not bring the battery to 100% charge for nearly 100 hours. On the other hand, a 90% full battery beats a cooked one anytime.
· 3 Stage Charge Controllers -
With a 3 stage charge controller, there are 3 steps to the charging process. The first 2 steps are the same. The bulk stage fills the battery to 90% full, and the float stage of the charge is the final stage, almost identical to the full charge voltage for the battery. The addition of a third stage in the middle, the absorption stage, is the difference in a 3 stage charge controller. The absorption phase of the charge consists of a voltage at the same rate as the bulk phase, but sophisticated electronics monitor this phase closely, and "TOP OFF" the battery at roughly 98%-99% capacity before flipping into "FLOAT" mode. Three stage charge controllers are able to "top off" or completely charge a battery more thoroughly and quickly than a 2 stage charge controller can. On the other hand, if the battery bank is under load while charging, the "absorption" step of the charging regimen can be "Tricked" into overcharging the batteries. The high end charge controllers are designed to flip into 2 stage mode if they sense a load to avoid damage to the batteries, but those less engineered should be avoided.
Due to the sophistication of the electronics, three stage charge controllers are more expensive, but are the "Cadillac" of the industry. Usually you can flip a 3 stage charge controller into 2 stage mode, and use it as either a diversion control or charge controller. When it comes to charge controllers, spend the cash to get a true 3 stage charge controller, and make sure it is from a reputable manufacturer. We know there are others, but we like these;
