BATTERIES

To achieve 50% cycling you should calculate your amp-hour consumption between charging cycles and use a battery bank with twice that capacity**. Each AC appliance or tool has a rating plate on it and will be rated in either AC amps or watts or AC VA (volt-amps) apparent power. To calculate amp-hour consumption, use one of the formulas to the right to calculate the DC amp-hour draw for a 12 volt system.

Calculate the amp hours for every AC appliance or tool that will be operated on the inverter. This will provide the total number of amp hours used between recharges. Size the battery bank using this number as a guideline. A good rule to follow is to size the battery bank a minimum of two times larger than the total amp-hour load requirement. Plan on recharging when 50% discharged.

AMP-HOUR CONSUMPTION FORMULAS(AC amps x 10) x 1.1 x hours of operation = DC amp hours(watts/ DC voltage) x 1.1 x hours of operation = DC amp hours(AC VA/ DC voltage) x 1.1 x hours of operation = DC amp hours

DC voltage is 12, 24 or 32, depending on your system.

In all formulas, 1.1 is the correction factor for

inverter efficiency.

Typical Power Consumptlon

The chart identifies typical power consumption for common AC loads. Use it as a guide when identifying your power requirements.

 

**Batteries are typically charged to 85% of full charge

Many electric motors have momentary starting

 

when charging with alternators without three-stage

 

regulators.

 

 

 

 

 

 

 

 

 

 

 

 

 

requirements well above their

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

operational rating. Start-up watts

 

 

 

Typical Power Consumption

 

 

 

 

 

are listed where appropriate.

 

Appliance

 

Typical

 

 

Appliance Run Times / Amp Hours

 

 

Individual styles and brands of

 

 

 

 

 

 

 

 

 

 

 

 

appliances may vary.

 

 

Wattage

 

 

 

 

 

 

 

 

 

 

 

 

 

5 Min.

15 Min.

30 Min.

1 Hr.

 

2 Hr.

 

3 Hr.

8 Hr.

24 Hr.

 

 

 

 

 

 

 

 

 

13" Color TV

 

50

 

.33

1

2

4

 

8

 

12

32

96

If using the same battery bank

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

for the inverter and other DC

 

19" Color TV

 

100

 

.66

2

4

8

 

16

 

24

64

192

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

loads, be sure to consider the

 

VCR

 

50

 

.33

1

2

4

 

8

 

12

32

96

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

power consumption of the DC

 

Lamp

 

100

 

.66

2

4

8

 

16

 

24

64

192

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

loads when sizing the battery

 

Blender

 

300

 

2

6

12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

bank.

 

Laptop Computer

 

50

 

.33

1

2

4

 

8

 

 

 

 

 

Curling Iron

 

50

 

.33

1

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3/8 Power Drill

 

500

 

3.3

10

20

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Icemaker*

 

200

 

 

 

2.6

5.2

 

10.4

 

15.6

41.6

83.2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Coffee Maker

 

1000

 

6.6

20

40

80

 

160

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3 cu' Refrigerator*

 

150

 

 

 

2

4

 

8

 

12

32

96

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20 cu' Refrigerator*

 

750

 

 

 

21

42

 

84

 

126

336

672

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Compact Microwave

 

750

 

5

15

30

60

 

120

 

180

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Full Size Microwave

 

1500

 

10

30

60

120

 

240

 

360

 

 

NOTE Certain laser printers, breadmakers,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Vacuum

 

1100

 

7.3

22

44

88

 

176

 

264

 

 

digital clocks and appliance/tool chargers

 

Number in each box represents the total Amp hours used (@ 12 volt DC) based on various continuous run times.

may not operate on modified sine wave.

14

*Note refrigeration is typically calculated using a 1/3-duty cyle.