7 Apr
2001
7 Apr
'01
1:25 p.m.
Thanks Joe and Tony. A further question is that some of the laptop batteries
have double positive and negative connection plates. Where these just to
ensure a good connection or are they actually 2 separate circuits. e.g.
2 6v in a 12 v pack ?
larry
At 10:36 PM 4/5/01 -0400, larry wrote:
Reply to:
lgwalker(a)look.ca
This is likely elementary but many times I run
across the encased laptop
and other function(eg cordless drills) batteries. Of course each has it's
own
proprietory
charger which have long since disappeared and are
costly to replace as
well as being
device and company specific . Many of them have a
3rd terminal. What was
it's
purpose.
Can you recharge these batteries simply by rigging up an interface using
appropriate
voltages and polarity ? How would you deal with
the 3rd terminal ?
Larry,
I'm assuming that your talking about NiCad batteries. If so, the third
terminal is usually connected back to the * battery terminal via a thermal
switch. The third terminal is used to recharge the batteries at a high
current rate (Quick Charge). The thermal switch has to be in the circuit to
prevent the batteries over heating and being damaged by the high current. You
can go ahead charge the batteries at a normal 1/10 C (or lower) rate via the
third terminal or the normal * terminal. The batteries will also last a lot
longer if they're charged at 1/10 C instead "Quick Charged". The charge
voltage
isn't critical in NiCads but the charging current is important.
Joe