15
FREQUENTLY ASKED QUESTIONS
Q.
When charging batteries what should I observe?
A.
If you want to see what’s going on then go to the CALIBRATION screen and you will be able to observe the
“Charge mA”.
With a relatively flat set of batteries when you first start charging you should observe a constant current of
around 230mA and “CHG” will be displayed (and a similar message on the MAIN screen). It will stay this way
for some time until the charging system switches to constant voltage. When this happens you should observe
the Charge mA slowly dropping. Eventually, when the mA drops below the
“Batt. Chg. Full mA” preset (see
SETTINGS) the charging will cease and “OFF” will be displayed. At this point the MAIN screen will display
“FULL”.
Q.
Why does the charge current suddenly drop to 0mA from 200mA+ when I am charging the batteries in the
PDVS2?
A.
The Lithium-Ion PP3 batteries are charged in series, as are the two cells within each battery. It is important for
successful charging that the batteries are the same capacity & type and have the same capacity of charge in
them before trying to charge them. Failure to do this can mean the internal protection circuit of one of the
batteries can detect a possible over charge and shutdown. The symptom of this is that when you are charging
batteries within the PDVS2 that it suddenly stops charging and the charge current drops to 0mA.
To fix this, remove the batteries from the PDVS2 and charge them separately in a standalone charger. This
will match them again and you can return them to the PDVS2.
If this problem persists then you may have a faulty/weak battery.
Q.
Can I run the PDVS2 without any batteries fitted?
A.
You can, but depending on the accuracy and stability you are looking for on the output it’s not recommended.
External DC supplies can sometimes generate noise and ground loops into a system. Running on batteries
negates this.This is also true when running with batteries and with the external DC Input connected.
Q.
What power source can I use to charge the batteries?
A.
Using the DC connector (tail) supplied you can use any electronic linear bench power supply that’s capable of
400mA (thus giving some margin). Just set it to 20Vdc. At this voltage you can also run the unit permanently
off the bench power supply. You can safely run it like this with the batteries installed because once the
batteries fully charge the charging circuit becomes disabled.
It is strongly advised to be very careful when using wall plug type power supplies since especially the linear
type can output a much higher voltage than is printed.
Also, it is advised not to use wall type switch mode type power supplies as these can be notoriously noisy.
Q.
Is there an Apple or Linux version of the PDVS2 Windows app?
A.
Unfortunately not, I am only able to write code for the Windows desktop. However, the ascii based serial
protocol is available on request if you want to write your own.
