# need the help to understand the circuit of the battery of the PDA(acer N300)

A

#### alex

Jan 1, 1970
0
I have bought a PDA (acer n300), and I can find nothing details about
its battery.
It is written on the back of the battery pack that:
Model NO: BA-1405106
Product Name: Acer n300 battery pack, rechargeable lithium-ion
battery
Rating: DC 3.7v 1200mAh

At the bottom of the battery, there are 6 pins (3 pins each side).

| | | | | |
a b c d e f

After charging the battery, I measured the tensions between all of
these pins. And I got the following results: condition 1: unused
situation
Condition 2: under use situation (while
the PDA works)
1) +
a
b 0
c 0 0
d 1.2/3.7 4 4
e 1.2/3.7 4 4 0
f 0 0 0 -4 -4
- a b c d e
f

2 ) +
a
b -3.2
c -3.2 0
d 0.6 4 4
e 0.6 4 4 0
f -3.2 0 0 -4 -4
- a b c d e
f

In condition 1, the tensions between the Pin A and D, the Pin A and E
vary in the two fixed values 1.2 and 3.7

And in condition 2, all of the tensions who are measured with Pin A
have descended by -3.2 v.
Is there anyone who can explain why this battery behaves like this? Or

M

#### M.Joshi

Jan 1, 1970
0
I was initially confused looking at the two sets of test results bu
after studying it for a while, I have created what I think is an easie
table for viewing them (See attached file).

I have bought a PDA (acer n300), and I can find nothing details about
its battery.
It is written on the back of the battery pack that:
Model NO: BA-1405106
Product Name: Acer n300 battery pack, rechargeabl
lithium-ion
battery
Rating: DC 3.7v 1200mAh

At the bottom of the battery, there are 6 pins (3 pins each side).

| | | | | |
a b c d e f

After charging the battery, I measured the tensions between all of
these pins. And I got the following results: condition 1: unused
situation
Condition 2: under use situatio
(while
the PDA works)
1) +
a
b 0
c 0 0
d 1.2/3.7 4 4
e 1.2/3.7 4 4 0
f 0 0 0 -4 -4
- a b c d e
f

2 ) +
a
b -3.2
c -3.2 0
d 0.6 4 4
e 0.6 4 4 0
f -3.2 0 0 -4 -4
- a b c d e
f

In condition 1, the tensions between the Pin A and D, the Pin A and E
vary in the two fixed values 1.2 and 3.7

And in condition 2, all of the tensions who are measured with Pin A
have descended by -3.2 v.
Is there anyone who can explain why this battery behaves like this? Or

+-------------------------------------------------------------------
|Filename: Battery Pack Voltage Measurements.txt
+-------------------------------------------------------------------

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