POWER ROOM EQUIPMENT

IN THE POWER ROOM, electricity from the solar array first passes through a charge controller, then through a fuse or circuit breaker disconnect device to the battery. From the battery, power goes through fuses or circuit breakers to any DC circuits in the house, and also goes through a large main fuse or breaker to the inverter/charger for producing 120 volts AC. Meters show power coming in from solar, wind or hydro, show battery condition and show how much power is being used in the house. This equipment mounts on the wall of a utility room, near the battery. The installer wires everything together into a functioning power system, in one of three ways.

COMPONENTS: In smaller power systems for cabins and recreational vehicles like examples #1 & #2, components are few and may be assembled individually by the installer. Solar charge control and inverter each connect to the batteries through their own cables with appropriate fuse in each cable.  Charge controls are explained and listed following the powercenters shown below. See Fuses and Hardware, and Meters for more information to round out these systems.

POWERCENTER Kit: A single box contains all DC circuit breakers, fuses, shunts and easy connection points for the cables from solar modules, battery, hydro or windmill, DC loads, remote meters and the inverter. The charge control and inverter often attach directly to the powercenter box, forming a single integrated unit. This saves having to find, buy, and assemble all the hardware separately. You get a simplified standard design which saves labor and time installing. The result is a safe, clean looking battery room. Powercenter components are UL approved, meet National Electric Code and are the simplest way to pass an electrical inspection. 

INTEGRATED POWER SYSTEM: Easiest of all, choose the fully integrated Outback FLEXWARE 500 power system. This ships as one unit, pre-assembled on a single mounting plate. Included are all matched components including a charge controller and 2,000 to 7,200 watt inverter combinations. You just connect your solar array, batteries, generator and house wiring.

CHARGE CONTROLS 
AS SEPARATE COMPONENTS

How to select a charge control

Charge controls prevent overcharging the battery. When battery voltage rises to a preset maximum, where the battery is completely charged, the control automatically reduces or stops the solar charge.

Some charge controls are that simple, but most include some other features like volt & amp meters, amp boosting, voltage conversion, or night light timer.

TRADING - UP
If you outgrow the capacity of a smaller charge control, you can trade it in for a larger control at Backwoods, if it was originally purchased from us.

VOLT AND AMPERE RATING OF THE CONTROL
Select a control able to handle a little more than the amperes your solar modules are rated to generate.  Though solar modules don't usually produce more than their rated amperes, they can momentarily produce 15% more on cold bright days. The electric code recommends leaving a 25% margin, that is, for a 47 amp solar array use a 60 amp control rather than a 50 amp control. And if you plan future expansion of your solar array, allow a lot more headroom to accommodate the added panels. Be sure the model you choose is designed for your battery voltage: 12, 24 or 48 volts. A given control will handle twice as many solar modules in a 24 volt system as in a 12 volt. Maximum power point tracking "Boost" and voltage converting controls are rated for the boosted output to the battery, not the slightly lower solar input amperes. If you outgrow the capacity of a smaller charge control, you can trade it in for a larger control at Backwoods, if it was originally purchased from us.

FEATURES

Since a battery voltmeter and solar amp meter are needed to show that the battery is really getting charged, most controls have those meters built in or optional. We always recommend a control with built-in amp meters and volt meters.

User-adjustable battery voltage set points is a feature of most controls, so voltage can be set exactly for your battery type, temperature and age.

Battery Temperature Sensor is available for some to  automatically adjust charge voltage for batteries exposed to large temperature changes.  

Automatic or Manual equalizing  gives an occasional overcharge to restore all cells to 100%.  

Maximum Power Point Tracking (or Boost) can increase the current a few amperes in some conditions.

  Voltage conversion allows charging a lower voltage battery from a higher voltage solar array while maintaining all the available solar charge power, to allow much longer and smaller wires between the solar array and battery.

HOW A CHARGE CONTROL WORKS

1. SERIES CYCLING CHARGE CONTROL is the simplest type that prevents overcharging of batteries by switching the solar panel current on and off periodically based on battery voltage. When battery voltage rises to a preset point indicating full charge is nearly reached, a mechanical relay or solid-state switch suddenly shuts off the charge. The battery voltage to begin to fall, eventually low enough to trip the control back on. Battery voltage rises again and the cycling method of charge control continues, off for a time, then on, then off... This results in battery voltage averaging somewhere between the high and low set points, preventing overcharge.
   

2. CONSTANT-VOLTAGE CHARGE CONTROL, usually 3-stage, is a more precise control to give the most charging possible for the day. BULK charge is first, with power switched straight through from solar modules until battery reaches a preset maximum.  ABSORPTION is the second stage charge where the maximum battery voltage is held by reducing the charge current just enough to never exceed the target voltage. Reduced current is done by high speed on and off pulsing, where the controlling "on" time versus the "off" time of each pulse determines the average charge current. FLOAT is a third stage where battery voltage is reduced after charge is complete. This avoids excessive evaporating of  battery water and benefits battery life. For those using sealed maintenance-free, AGM or gel type batteries, three stage with float is the only safe method of charge control. 
   

3. DIVERSION CHARGE CONTROL does not cut off current from the charging source at all. When the battery charges to the maximum set voltage, a diversion control senses that voltage and consumes or "burns off" excess current to exactly off-set the excess charge, and keep thee battery voltage at, never exceeding, the preset maximum. This comes out as a small amount of heat in ceramic air heating resistors or water heating elements. The control adjusts its consumption rate to offset the excess charging exactly, and keep the battery voltage at, and never exceeding, the preset maximum voltage. If you use a windmill that does not have its own charge control, or use hydroelectric generating, a diversion control must be used, since those generators can be damaged if their charge is not absorbed in the batteries at all times. One diversion control handles a combination of solar, hydro and wind, so long as the total amps charge from all of them taken together is within its amp capacity.
   

HOW MAXIMUM POWER POINT TRACKING WORKS (Outback & Blue Sky Energy brands)

Charge Current Boost:
Silicon crystal solar modules are rated maximum power at 16.5 to 17 volts. They are given this extra margin because these panels drop one or two volts in hot weather. But in cold weather they have more voltage than can be used. Maximum Power Point Tracking converts this unused higher voltage to increased battery charge current. A 75 watt solar module gives 4.4 amps maximum. In full sun you get that 4.4 amps whether at the rated 16.5 to 17 volts, or whether it is pulled down by the battery to 12.5 volts. 17 volts x 4.4 amps = 75 watts, but 12.5 x 4.4 gets only 56 watts to the battery. The boost control lets the solar module operate at peak power 17 volts where it gives the full 75 watts. The control converts the extra watts to increased amps when battery is low at 12 or 13 volts  and weather is cold. Solar module voltage and the boost effect are highest in cold weather when the batteries are low, and that is also the time many of us really need this advantage.

Select a control rated for 25% MORE amperes than non-boosted output to the battery would be, to allow headroom for the boosted (increased) current. This rating refers to the maximum output amperes to the battery, NOT input amperes if at a different voltage. 

Solar Voltage Conversion by Charge Controls:
The same process allows arrays for 24, 36, 48, and even 60 volts to be converted in the charge control to charge a lower voltage battery. This allows higher voltage and lower current in solar module wires; which means longer wire runs of much smaller wire size from the array connecting to the charge control.

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XANTREX C-35, C-40 and C-60 CONTROLS

C-35  35 Amps; 12 or 24 volt
C-40  40 Amps; 12, 24, 48 volt
C-60  60 Amps; 12 or 24 volt

3-stage voltage control

Series for Solar 
or Diversion for Hydro or Wind

2 year warranty
Size 9" x 5" x 2"
Built in terminals accept wire size up to 2 gauge

CONSTANT CHARGE VOLTAGE: Most advanced control method has 3 stages: full solar charge to Bulk Voltage you set as maximum, then tapers off charge in Absorption mode, just enough to keep batteries at, but not exceeding, the bulk voltage you set. After one hour at bulk voltage, a lower Float Voltage takes effect to prevent overcharge. 

DIVERSION CONTROL: XANTREX C35, C40 & C60 can be used as diversion control for wind or hydro. To set up as diversion control, order air or water heat diversion resistors.

BATTERY  EQUALIZATION: Higher voltage automatically equalizes batteries once a month, or can be started manually anytime, or disabled for sealed batteries.

OPTIONAL DIGITAL DISPLAY of both charge amps and battery volts, plus counts amp-hours of charge since last reset. Highly recommended.

C-35DD Charge Control & Digital Display:  $210 (ship $12)
C-40DD Charge Control & Digital Display:  $245 (ship $12)
C-60DD Charge Control & Digital Display:  $280 (ship $12)

Any of the above are available without digital display, deduct $99

I- TEMP Optional plug in battery temperature sensor................ $29
C- X DVM Add-on digital display for either control:.................. $99
C- 40R/50 Remote Digital Display with 50' cable:...................... $115
C- 40R/100 Remote Digital Display with 100' cable:.................. $135

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OUTBACK CHARGE CONTROL-- MX60 and FM80

Maximum Power Point Tracking
To Boost Solar Amps
For 12 Through 48 Volt Batteries

Can also charge 12 or 24 volt Battery
from up to 72 Volt PV Array; not to exceed 150v open circuit

	Outback MX60 14.5" x 6" x 6" 12 pounds 2 year Warranty         Outback FM80 16.25" x 6" x 6" 5 year Warranty		Outback MATE Accessory

Multi-stage charging: Bulk, Absorption, Float, and Equalize.
60 amps of DC output current to charge batteries at 12, 24, 32, 36, 48, 54, or 60 volts DC. Regulation voltage is adjustable from 13 to 80 volts DC.

Maximum Power Point Tracking Since the control can boost output current, solar input equal to 48 amps of charging is maximum recommended for the MX60 (maximum rated output: 60 amps) and 64 amps for the FM80 (maximum rated output: 80 amps).

Use higher voltage PV array with lower battery voltage -like charging a 24 volt battery with a 48 volt PV array- reduces wire size and power loss, while increasing the distance possible from the PV array to battery. Accepts any array voltage up to 72 nominal volts and matches to any lower battery up to 48 volts.

The four-line 80 character, backlit LCD display standard on the Outback MX60 and FM80 displays the PV system's performance. It is also used for easy programming and monitoring of the system's operation. Terminals accept up to 4 gauge wire.

Outback MATE system controller, optional accessory, connects to the MX60 as a remote control. MATE duplicates the built-in control panel that comes with the MX60 and FM80. MATE can also program and remote control Outback inverters, from a location 300 feet distant. MATE includes a RS232 computer port for data logging.

C-MX60 Outback Charge Control...............$580 (shipping $15)
C-FM80 Outback Charge Control...............$680 (shipping $15)
C-OBK MATE System Controller...............$295
C-OBK TEMP Compensates charge voltage for battery temperature...$29