Section 2 | Specifications
©
2022
–
Valeport Ltd
Page | 8
2.4.2 Based on Batteries
The MIDAS SVX2 will function with a voltage supply of between 9 and 30vDC. The voltage output
of the 8 x C cell battery pack will vary according to the type of cell fitted. The most likely cells to be
used will be standard alkaline type (1.5v each) or Lithium cells (3.6v each), giving a 12v nominal
output for alkaline cells, or 28.8v nominal for Lithium cells. The following calculations are based on
the same sampling scenarios as the memory calculations, using figures for a 12v alkaline battery
pack. Each example also gives a figure for a Lithium battery pack, calculated from a basic ratio of
alkaline to Lithium performance.
In all examples, it is taken that an 8 C cell alkaline battery pack will have a nominal capacity of
7.8Ah, and will be 75% efficient (total available charge, 5.85Ah), and that an 8 C cell Lithium pack
will have a nominal capacity of 7.2Ah, and will be 95% efficient (total available charge, 6.8Ah).
Continuous Data Sampling, 8Hz:
At 12v, the instrument draws
60mA
when sampling.
Total charge available is
5 850mAh
.
Number of hours available is therefore 5850mAh / 60mA =
97 hours
.
This is equivalent to just over
4 days
.
For Lithium cells, a similar calculation gives around
11 days
.
The instrument is effectively operating continuously when in Trip sampling mode, so similar
calculations will apply.
Burst Sampling, 4Hz, Sampling for 1 Minute Every 10 Minutes:
At 12v, instrument draws 60mA when sampling, plus 60mA for 5 seconds at the start of each burst.
It draws 0.25mA when in sleep mode between bursts.
In this scenario then, the instrument will draw 60mA for 65 seconds, and then 0.25mA for 535
seconds.
On average, it will draw:
Total charge available is
5 850mAh
.
Number of hours available is therefore 5850mAh / 6.72mA =
870 hours
.
This is equivalent to approx
36 days
.
For Lithium cells, a similar calculation gives approx
100 days
.
The above examples are intended as guides only. Valeport cannot accepts responsibility for
variation in actual performance.
Performance of individual battery cells is not always consistent.