BATTERY CHARGERS

A battery charger converts AC power from the generator or from the power company into low voltage DC to charge a battery. The ability to charge batteries from these sources during poor solar weather avoids battery damage from extended periods of severe discharge.

Some small AC generators have a built-in DC battery charge feature of only 3 to 10 amps. To be effective, one or more 30 to 100 ampere battery chargers should be connected to your AC generator and can charge while the generator runs a washing machine or well pump, making the best use of costly generator time. 

 GENERATOR REQUIRED: Battery chargers need a full sine wave 120 volts AC to give their rated amount of charge. Most under $2500 also have low peak voltage causing many chargers to give only a fraction of their claimed charge rate. This may be cured with our 10% voltage boost transformer. Some generators can be adjusted for slightly higher speed to maintain 120 volts to compensate. Allow minimum generator size of 1 KW (1 kilowatt) per 30-amp 12-volt charger.  Beware low cost 120/240 volt generators with only half rated wattage on each 120 volt circuit. Trace inverter-chargers that are not true sine wave need a 6 KW or larger generator. EXCEPTION: We recommend Electronic Inverter-based variable speed generators like the Honda EM5000i or the EU3000 and Yamaha 2800I which operate battery chargers up to 100 amperes/ 12 volts (50 amperes/24 volts) at full charge rate. Also see the GEN-TEST volt & frequency meter for generators. 

CHARGER SIZE & TYPE: Compatibility of generator and charger can be a big problem. Battery chargers of 30 to 150 amperes built into True Sinewave  "standby" inverter-chargers, and the separate electronic battery chargers below work well with nearly any generator. The Electronic Inverter-based generators, described above work well with nearly any charger. 

Maximum charger amps should be about 10% of the battery amp hour rating. Charging too fast can damage batteries. A 440 amp hour battery works well with a 40 ampere charger. Charge rate should taper to a much lower rate as the battery becomes fully charged. Several chargers can be used together to increase charge rate and reduce charge time, if the battery size and rating of the generator allow. NOTE: Many automotive chargers list a high "boost" 200 amp or higher short term engine start surge, but this setting CANNOT function for charging home power batteries.   For more, see The Battery Book.

BATTERY BOOSTER  Engine - alternator kit in the generator section works well with small power systems.

ELECTRONIC 12 volt BATTERY CHARGER
by XANTREX

BEST CHARGER working from generator power source.

Microprocessor controlled, 40 amp continuous duty, multi-stage battery charger (12 volt only, or use two in series for 24 volt)

15" x 7" x 3"
Weight 8 pounds

TRUECHARGE 40 + is a high reliability 40 amp electronic battery charger for deep cycle batteries. Switch settings give correct charge for wet, gel cell, or absorbed glass mat batteries. Selectable 2 or 3 stage charging where 3 stage includes float charge. Manual equalize charge button. Manual or automatic temperature compensation. Optional temperature sensing probe to correct charge voltage for actual battery temperature.

This charger has full 40 amp output even with low cost generators, an important quality if your generator cost under $2500.  Backwoods comparison tested all our battery chargers with several generators. Most chargers performed as promised with the big Kohler 10 kilowatt generator, but most gave less than half the charge with the Honda 3500 generator. Those that delivered full rated power even with the smaller generator were true sine wave inverter-chargers and this TrueCharge 40+. As with all battery chargers, as battery voltage increases it is not unusual to witness a decrease in charging current.

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IOTA 12 VOLT 55 AMP and 24 VOLT 25 and 40 AMP CHARGER

Iota Engineering uses advanced switch mode technology in the production of this highly sophisticated electronic battery charger. The DLS series converter efficiently charges batteries with its full rated output. It then maintains the batteries by only putting into the battery bank what is required to maintain the selected voltage set point. Short circuit, overload, and thermally protected. These chargers do not have a float feature.

Historically, low and transient AC line voltage was a major cause of battery charge failure. The DLS series is protected against low line voltage as well as spikes coming from your AC power source. It also meets FCC criteria for minimizing radio and television equipment interference.

TWO year warranty

Model DLS5512 is a 740 watt power supply. It can deliver a 55 amp maximum charge at 12 volts, fully automatic. Backwoods maximizes the voltage set points at either 14.8 or 15.4 volts. These set points are user selectable via simple plug-in jack.  As with all battery chargers, as battery voltage increases it is not unusual to witness a decrease in charging current.
 
Model DLS2425A is a 675 watt power supply. It can deliver a 25 amp maximum charge at 24 volts (equal to a 50 amp/12 volt charger). Fully automatic.  Backwoods maximizes the voltage set points at either 29.2 or 28.2. These set points are user selectable via a simple plug-in jack.  As with all battery chargers, as battery voltage increases it is not unusual to witness a decrease in charging current.

Model DLS2440A is a 1100 watt power supply. It can deliver a 40 amp maximum charge at 24 volts (equal to a 80 amp/12 volt charger). Fully automatic.  Backwoods maximizes the voltage set points at either 29.2 or 28.2. These set points are user selectable via a simple plug-in jack.  As with all battery chargers, as battery voltage increases it is not unusual to witness a decrease in charging current. 120v 20 amp outlet required for this charger. This outlet will have one vertical and one horizontal spade receptacle as well as the standard ground prong receptacle.

7 x 6.5 x 3.5 inches. Weight 5.5 pounds.

BATTERIES

BATTERY CARE is your main responsibility with home made electricity. This is the one part of your power system likely to be harmed by neglect or misuse. Lead-acid batteries, the standard in home energy, should not discharge more than 50%. Ideally, they should be recharged to 100% promptly. They can be damaged by undercharging, continued overcharging, or contamination. Do not store batteries without periodic recharging. Continual self discharge when not in use can ruin even a brand new set of batteries.  The Battery Book (E-BATTERY, $10) is an easy guide to getting the most life from batteries.

Sizing of 1000 to 2000 amp-hour 12 volt (or 1/2 that in 24 volt; 1/4 that in 48 volt) battery bank is desirable because a larger bank can accept faster charging by generator and give high power discharge for inverter surge without strain. In northern areas short on winter sunshine, more reserve before running down to the 50% level is also a benefit. Use our catalog's 6 introductory examples as a guide to battery size, or call for advice. In sunny southwest, less battery capacity is needed. 

DEEP CYCLE lead acid batteries have thicker plates and lead-antimony support grids for years of over 50% deep cycle charge and discharge. Golf cart batteries, the "L-16" and the "L-16HC" industrial batteries are the most common. Surplus industrial batteries may be deep cycle lead-antimony, or pure lead, or may be shallow cycle lead calcium construction.

Auto batteries are shallow cycle only. Cat, automobile, and truck batteries are NOT deep cycle and will not last long in home power systems. These have thinner plates and lead-calcium grids designed for less than 20% discharge and immediate recharge. If an industrial lead-calcium battery is well oversized so that normal cycling uses only the top 20% of battery capacity, lead calcium cells can be used. 

RV/MARINE  This common 12 volt battery is designed about half way between a deep cycle and a shallow cycle, and has medium length of life.

SEALED BATTERIES  Gel or AGM (absorbed glass mat) types damage easily from overcharge, and so should be used with a 3 stage charge control. Sealed batteries can be excellent deep cycle alternative energy batteries, cleaner and safer, but only if charging is precisely controlled. Since water cannot be replaced and hydrometer testing is not possible, they are considered special purpose batteries. 

NICKEL CADMIUM (ALKALINE) BATTERIES: Unlike lead, deep discharge and failure to recharge do not shorten battery life. However, surplus batteries are often overpriced and defective. Cost is much higher than lead acid. Voltage swings higher when charging and lower when using. Charge efficiency (energy charged in versus energy returned to you) is very low. Disposal and recycling can be difficult and costly. Be cautious of buying used alkaline batteries.

Backwoods Solar Stocks TROJAN BATTERIES

In our opinion, the best deep cycle battery in this class available for our off-grid systems!

TROJAN T-105 always in stock to pick up at Backwoods Solar.
TROJAN L-16 HC orders to pick up here should call at least a week ahead.

FREE PICK UP in OTHER AREAS:  Batteries ordered from this catalog can be picked up at Trojan dealers in much of the U.S. Usually with no shipping charges or tax. Call for arrangements. Shipping wet batteries is rarely necessary. 

TROJAN T-105 BATTERIES NEW 225 AMP-HOUR RATING

Electric Vehicle or Golf Cart Batteries are easier to lift at 65 pounds each, size 10" x 7" x 11". These are a popular and economical battery for home power systems. This mass produced consumer battery has the best price per amp-hour of any quality battery.

Each battery is 6 volts, made of three 2-volt cells in one unit. Six-volt batteries are series connected in pairs for 12 volts, or in strings of four batteries for 24 volts, or 8 to make 48 volts. Then several of these series strings may be parallel connected to add more ampere-hour capacity. Each series string is rated 225 ampere hours, so two strings are 450 Ampere-Hours, 3 are 675 A.H., 4 are 900 A.H., 5 are 1125 A.H., etc. Interconnect diagrams are supplied. Life expectancy is 4 to 6 years. 12 month warranty. 

FREE ACCESSORIES included with Trojan batteries are the Battery Book, and a glass hydrometer. Distant customers call for pick-up locations near you, usually at no shipping cost.

Order your choice of battery interconnect cables.

Due to the global lead market, battery prices may differ throughout the country and prices are subject to change without notice!

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TROJAN L-16 HC High Capacity BATTERIES
NEW, HIGHER CAPACITY RATING-- NOW 420 AMP-HOURS

As of 9-1-2006, Trojan offers a free replacement warranty for the first two years of service and an additional five year, pro-rated warranty on the L16HC battery for renewable energy systems (assuming Trojan defined, proper care)!!

Trojan L-16 HC is a 420 amp hour industrial size 6 volt battery weighing 120 pounds. Lifting handles are included. They are 30% taller than auto or golf cart batteries, 12" x 7" x 16 inches tall, so they take less floor space for a given battery capacity. Typical life is 8 - 11 years. L16 HC is High Capacity model in a red ribbed case with two handles, Trojan's best. Not the standard L-16 model which has less capacity. Both have a reputation of reliability in home power systems.  2 year full warranty plus 5 more years prorated warranty on the L16H.

Each battery is 6 volts, made of three 2-volt cells in one unit. Six-volt batteries are series connected in pairs for 12 volts, or in strings of four batteries for 24 volts or 8 to make 48 volts. Then several series strings may be parallel connected to add more ampere-hour capacity. Interconnect diagrams are supplied. Each 12 or 24 volt series string of L16 HC is rated 420 Ampere Hours, so two strings are 840 Ampere-Hours, 3 are 1260 A. H; 4 are 1760A. H; 5 strings are 2100 A. H.... etc.

FREE ACCESSORIES included with batteries: the Battery Book, and a Freas #1  glass hydrometer. Distant customers call for pick-up locations near you, usually at no shipping cost.

Call at least 1 week ahead to pickup L-16HC batteries at Backwoods.

Order your choice of battery interconnect cables.

Due to the global lead market, battery prices may differ throughout the country and prices are subject to change without notice!

SURRETTE HEAVY DUTY INDUSTRIAL BATTERIES

This new generation, deep cycle, flooded lead acid battery offers high capacity and heavy duty plate grids which resist positive plate breakdown. The plates are double insulated with glass mat and polyethelyne envelope, eliminating the possibility of separator misalignment, cracked separators, and shorting.

Each 2 volt cell is built into its own lightweight container made of durable polypropylene. The cells are then assembled into a tough outer container with a removable lid. Even if this outer container cracked, acid spills are prevented and the battery still operates. The individual cells are bolted together allowing the battery to be disassembled and the cells individually removed for easy on-site installation. Free battery book and Hydrometer included with each purchase.

Rated at 3200 Cycles at a 50% Depth of Discharge. Ten year warranty: three years full warranty; and then seven years pro-rated warranty.

FREIGHT to be determined. Call for a freight quote.  Please allow 4-6 weeks for delivery. Battery interconnect cables included with each order!!

Due to the global lead market, battery prices may differ throughout the country and prices are subject to change without notice!

CONCORDE   ABSORBED GLASS MAT 
SEALED BATTERIES

Completely sealed valve regulated Absorbed Glass Mat (AGM) battery. Non-spillable and maintenance free, never requires watering. No gas, it is all recombined within the battery. Exterior stays clean and safe. AGM has no problems like gel batteries separating from plates. Can be transported safely by air or any other means, and is exempted from DOT hazardous material category. No UN labels required for international air shipping. Recyclable anywhere that processes automobile batteries. See a report on these in Home Power Magazine issue 75 page 88. Sealed batteries require 3 stage charge control set exactly to manufacturer's instruction, and NO equalize charging. 12 month warranty after install, or 18 months from date of purchase. Order interconnect cables separately. Expected life is 5 years at 30% depth of discharge.

A 7.5% California sales tax fee will be added to any order shipped to a California address unless a CA Resale certificate is provided.

Call for truck freight shipping on 12 volt; 6 volt goes UPS $30 each.

Due to the global lead market, battery prices may differ throughout the country and prices are subject to change without notice!

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BATTERY ACCESSORIES

HYDROMETER is the lowest price, most direct and reliable indicator of battery state of charge. We give one free with each battery purchase. Includes battery record sheet and instructions.

The BATTERY LIFE SAVER DE-SULFATOR is a pulse style battery conditioner. Battery Guru, Richard Perez, of Homepower magazine insists that a battery de-sulfator is an essential battery bank component. This de-sulfator purportedly sends a square wave frequency signal to each crystal of lead sulfate, causing it to convert back into lead and sulfuric acid, thus dissolving the crystal. The end result: longer battery life!

Tom Kingsland, a Backwoods employee, tested this device on his 6 year old Trojan T-105 battery bank and witnessed impressive results. Please call and ask Tom to discuss his test results.

Simple installation with two battery clips: one for your Battery (+) and one for the Battery (-). The reverse polarity protected, potted electronics are set on an anodized aluminum heat sink.
4.5" wide x 2.25" deep x 2.0" high.  11.4 ounces   One year Warranty

The Water Miser Battery Cap is designed to reduce battery maintenance by decreasing the frequency with which distilled water needs to be added to each cell and also alleviates some of the minute electrolyte mist which can settle atop a battery. Each cap has condensing pellets within its flip top lid which capture and return electrolyte droplets into each cell as battery charging takes place. This process does NOT eliminate the need to add distilled water!

Each battery cell needs one Water Miser Cap which will replace the original cell's cap.

O-AU 4/0 Single Lug: $7
0 - AU 2/0 Dual Lug:  $4

BATTERY INTERCONNECT CABLES
To connect individual batteries together. Total load divides equally among battery strings in parallel so 2 gauge may be adequate within each series string. Heavier 2/0 is for connections between ends of series strings. Heaviest 4/0 Shunt Cable connects battery negative to meter shunt, or for longer cable between shelves or rows of batteries.  Eyelet lugs on both ends as pictured. Eyelet lug on each end as pictured. For larger gauge10 foot cables, see inverter battery cables.

SHIPPING ON BATTERY CABLES TO BE DETERMINED

Minimum shipping $6 per whole order covers all items with no shipping listed

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BATTERY BOX VENT FAN

AUTOMATIC CONTROL FOR 12 or 24 VOLT BATTERY FAN

Voltage- controlled switch automatically runs vent fan when battery reaches gassing voltage of 14.0/28.0 volts or higher. Holds fan on for 15 minutes after voltage drops to 13.8/27.6 or less, then shuts down. LED shows when fan is operating. Manual switch to turn on or off at any time. Will run the 12 or 24 volt, or one or two brushless muffin fans (fan not included). 

LOW COST BATTERY VENT BRUSHLESS FAN

4-5/8 inch square brushless motors use little power, can be installed on battery box or in vent system. Auxiliary relay option in Xantrex SW+ inverter can start and stop these based on battery voltage, or connect to the 12 or 24 volt control shown above for any 12 or 24 volt system. Rated 40 to 90 cfm. Current varies with model & voltage, usually 0.2 to 0.5 amps.

A-MUFFAN 12:  $15
A-MUFFAN 24:  $15
A-FANGUARD: Screw-on guard to protect from fan blades $3

BATTERY BOOK FOR YOUR PV HOME   by New England Solar This booklet covers lead acid batteries like Trojan T-105 or L-16HC. Interconnecting, care and testing, hydrometers, voltage readings, and battery equalizing explained. We give this book free with each battery sale. 22 pages, 8½ x 11"

E-BATTERY:  $10

Minimum shipping $8 per whole order covers all items with no shipping listed

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