Panasonic PT-DZ12000U Operating Instructions Manual page 148

B. Battery Systems
When using batteries to power vacuum pumps you must
consider the continuous run time you need to get from your
battery system.
Use the following table and equation to determine your
battery requirements after you establish how many watt-hours
of power you need from the system.
Example: You have a DC operated vacuum pump that uses
250 watts per hour. Your want to continuously operate your
vacuum pump for 8 hours. The watt-hrs you need from your
battery system is 250 watts times 8 hours (2,000 watt-hrs).
Battery Watt-hrs per kg
Type battery weight
Li-Ion
NiMH
NiZn
The batteries with the highest power density will be the
lightest for your application but the price will be the highest.
The lowest price for a battery system will be Lead Acid but will
be the heaviest battery system.
If your vacuum pump is AC operated then you must factor
in a DC to AC converter which increase the system cost and
weight. You will also have a power conversion factor of
around 90% so you will need extra battery power.
135
78
52
137
Battery Watt-hrs per kg
Type battery weight
NiCd
Alkaline
Lead Acid
47
80
37