1. Solar Power Controllers

2. Why you need to know about controllers A charge controller is an essential component of any battery-based system because it protects the batteries from excessive overcharge, which can shorten their life and create hazardous conditions.

3. There are different kinds of controllers Some charge controllers work by opening the charge circuit (or 'turning off' the PV array) when the batteries near full charge. Other controllers work by reducing the charge current into rapid 'pulses' of current known as PWM (Pulse Width Modulation) keeping the batteries at a constant voltage..

4. Continue A third type of controller, diversion controllers, work by diverting portions of the charge to external loads (like water heating elements or other types of resistive loads) when the batteries near full charge. Diversion controllers are the choice with wind and hydro systems and they can work in conjunction with solar controlling the charge to the same battery.

5. What is the best controller? For optimum efficiency charge controllers should be sized proportionally to the maximum charge current in the system. If you plan on increasing your charge capacity in the near future, over sizing the controller initially is a good idea.

6. XANTREX C-35, C-40 & C-60 These multi-function charge controllers can regulate not only PV charging but can function as a diversion controller for wind and hydroelectric generators. Pricing: C-60 (60 amp charge controller)...$185 C-40 (40 amp charge controller)...$145 C-35 (35 amp charge controller)...$105. Pricing: C-60 (60 amp charge controller)...$185 C-40 (40 amp charge controller)...$145 C-35 (35 amp charge controller)...$105.

7. Solar Boost by RV Power Products Solar Boost controllers by RV Power Products employ Maximum Power Point Tracking (MPPT) which increases charge current up to 30%. These controllers offer series pass Pulse Width Modulation (PWM) charge voltage control using reliable power MOSFET transistors. A fully automatic electronic current limit prevents overload. Solar Boost 3048 (30 amp, 24/48 volt) with UL listing is $479. Solar Boost 50L (50 amp, 12/24 volt, UL listed)is $419. For display add $80.

8. SunSaver Morningstar's SunSaver ia a small solar controller for both professional and consumer applications. LVD (low voltage disconnect) option avail. SunSaver-6 (12 Volt)48 SunSaver-20 with LVD (24 Volt)101

9. What is "LVD" and why is it useful? LVD is an acronym for Low Voltage Disconnect. SunSavers equipped with this feature will disconnect the DC load if the battery is discharged too low. This will protect the battery from over-discharge, which can cause damage. When the battery recharges to a reasonable level, the DC load is reconnected.

10. What is the purpose of the Temp Sensor? The temperature sensor measures ambient temperature. Battery chemistry is sensitive to temperature and the SunSaver charges batteries as a function of temperature. If it is warm, the batteries will be charged to a slightly lower voltage and if cold, to a slightly higher voltage. This is referred to as temperature compensation.

11. Works Sited www.morningstarcorp.com www.burnhambeck.com www.windandsun.com