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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.
|
BC-TRUECHARGE 40 +: Regularly
$410 (Shipping $14) |
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|
I-Pro Temp: 25' temperature sensing probe corrects charge voltage: $30 |
 |
|
BC- 40Remote: remote control panel with 20' of comm cable: $40 |
 |

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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.
|
BC-IOTA
5512..............Regularly
$185
(shipping $10)
|
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BC-IOTA 2425.............Regularly
$250
(shipping $10) |
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|
BC-IOTA 2440...120v
20 amp outlet required.......... $385 (shipping $10) |
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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.
|
B-T105: Trojan T-105 Batteries & accessories EACH:
$152 |
 |
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.
|
B- L16HC: Trojan L-16HC
batteries & accessories EACH: $395
|
 |
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.
|
Model |
Volts |
Amp-
Hrs |
Length |
Width |
Height |
Lbs |
Price |
|
|
B-2-KS-33PS |
2 |
1766 |
15.44 |
8.32 |
24.82 |
208 |
$795 |
 |
|
B-4-KS-21PS |
4 |
1104 |
15.75 |
9.38 |
24.75 |
267 |
$1055 |
 |
|
B-4-KS-25PS |
4 |
1350 |
15.75 |
10.63 |
24.75 |
315 |
$1295 |
 |
|
B-6-CS-21PS |
6 |
683 |
22.00 |
9.75 |
18.25 |
271 |
$1015 |
 |
|
B-8-CS-25PS |
8 |
820 |
28.25 |
11.25 |
18.25 |
424 |
$1580 |
 |
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.
|
B-2580L 12 volt, 21" x 11" x 10"
162 pounds 255 amp hours: $690 |
 |
|
B-2120L 12 volt, 21" x 9" x 10.5" 135 pounds 210 amp hours:
$550 |
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|
B-2240 6
volt, 10.5" x 7" x 11" 68
pounds 220 amp hours: $295 |
 |
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.
|
0-HYDROMETER: Freas #1 Basic
model: free with battery purchase $20
In Stock |
 |
|
0-HYDROMETER: Freas #2: our
most accurate. 1.100 to 1.325 in 0.05
increments and now temperature compensated!! (The
float no longer has bumps as advertised in
our Summer 2007 Newsletter.) $35
In Stock!! |
 |

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
|
B-BLS12
for 12v systems draws 250 ma maximum: duty cycle 50%: $84
|
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|
B-BLS24
for 24v systems draws 250 ma maximum: duty cycle 50%: $84 |
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|
B-BLS48
for 48v systems draws 500 ma maximum: duty cycle 50%: $84
|
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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.
|
B-WATER MISER CAP:
$6 per cap |
 |
|
BATTERY LUGS fits on 5/16 battery bolt or 3/8 meter shunt
bolt. Allen screws clamp one or two wires up to 2/0 size, or many smaller wires down to 14
gauge. With allen wrench.
|

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| O-AU 4/0 Single Lug: $7 |
 |
|
0 - AU 2/0 Dual Lug: $4 |
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BATTERY TERMINAL COATING Keeps vapors, atomized battery acid, and air off battery terminals, bolts, and wire
ends. 3 ounce bottle with applicator does all your battery bank and auto batteries too.
|
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|
O-BAT COAT: $12 |
 |
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.
|
O-BIC 2: 2 gauge copper, 15" with 5/16" holes, for
Trojan batteries: $8 |
 |
|
O-BIC-2/0: 2/0 heavier gauge copper, 16" with 3/8"
bolt holes: $12
|
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O-SHUNT CABLE 2/0: 2/0 copper, 24" with 3/8"
bolt holes: $18
|
 |
|
O-2' SHUNT CABLE 4/0: 4/0 copper, 24" with 3/8 bolt
holes: $20
|
 |
|
O-3' SHUNT CABLE 4/0: 4/0 copper,
36" with 3/8 bolt
holes: $30
|
 |
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
|
Ready made 12, 24, or 48 volt fan in pipe sections with
back draft damper for easy installation in your battery vent pipe.
The automatic switch below will control a 12 or 24 volt fan. 12 and 24
volt models go in 2 inch PVC pipe. The 48 volt model has a 2 inch inlet
and a 3 inch outlet pipe socket.
|

|

|
|
O-PWRVENT 12 volt: $74 |
 |
|
O-PWRVENT 24 volt: $74 |
 |
|
O-PWRVENT
48 volt: $98 |
 |
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).
|
O-BATVENT 12v CONTROL: $84 |
 |
|
O-BATVENT 24v CONTROL: $84 |
 |
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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